From the University of British Columbia:
Compared to its celestial neighbors Venus and Mars, Earth is a pretty habitable place. So how did we get so lucky? A new study sheds light on the improbable evolutionary path that enabled Earth to sustain life.
The research, published this week in Nature Geoscience, suggests that Earth’s first crust, which was rich in radioactive heat-producing elements such as uranium and potassium, was torn from the planet and lost to space when asteroids bombarded the planet early in its history. This phenomenon, known as impact erosion, helps explain a landmark discovery made over a decade ago about the Earth’s composition.
Researchers with the University of British Columbia and University of California, Santa Barbara say that the early loss of these two elements ultimately determined the evolution of Earth’s plate tectonics, magnetic field and climate.
“The events that define the early formation and bulk composition of Earth govern, in part, the subsequent tectonic, magnetic and climatic histories of our planet, all of which have to work together to create the Earth in which we live,” said Mark Jellinek, a professor in the Department of Earth, Ocean & Atmospheric Sciences at UBC. “It’s these events that potentially differentiate Earth from other planets.”
On Earth, shifting tectonic plates cause regular overturning of Earth’s surface, which steadily cools the underlying mantle, maintains the planet’s strong magnetic field and stimulates volcanic activity. Erupting volcanoes release greenhouse gases from deep inside the planet and regular eruptions help to maintain the habitable climate that distinguishes Earth from all other rocky planets.
Venus is the most similar planet to Earth in terms of size, mass, density, gravity and composition. While Earth has had a stable and habitable climate over geological time, Venus is in a climate catastrophe with a thick carbon dioxide atmosphere and surface temperatures reaching about 470 C. In this study, Jellinek and Matt Jackson, an associate professor at the University of California, explain why the two planets could have evolved so differently.
“Earth could have easily ended up like present day Venus,” said Jellinek. “A key difference that can tip the balance, however, may be differing extents of impact erosion.”
With less impact erosion, Venus would cool episodically with catastrophic swings in the intensity of volcanic activity driving dramatic and billion-year-long swings in climate.
“We played out this impact erosion story forward in time and we were able to show that the effect of the conditions governing the initial composition of a planet can have profound consequences for its evolution. It’s a very special set of circumstances that make Earth.”
###
What – no warning that we are on our way to become Venus II if we don’t park our cars right now? What incompetent communication office botched this press release?
Well the primary reason we live on “Earth” and not “Venus”, is because that’s what they named the place.
What idiot would call their home planet MW_OA 2/3_M 4392_3 as if it was just some entry in a star catalogue.
And in any case if we did happen to live on that planet I mentioned above, we would be a life form that could evolve compatibly with the conditions on that planet.
We are here, because if the conditions were considerably different like they are most other places; something else would be here instead of us.
g
+ rather a lot.
Auto
As Spike Milligan’s character in the Goons says “every ones got to be somewhere”.
James Bull
The Earth is roughly 93,000,000 miles from the sun, and Venus is roughly 67,200,000 miles. When the Earth drifts 25,000,000 miles closer to the sun, I’ll start to worry.
Does CO2 cause orbital decay?
/snark
Of course CO2 causes orbital decay. CO2 is the magic molecule. I am disturbed by you lack of faith.
Me too.
Terribly disturbed.
Somebody call Lew and Cook.
Let’s get this fixed, asap.
The biggest question is why Jupiter didn’t wander inward and eject the inner rocky planets out of the solar system, gobble them up, crush them like the asteroid belt, or put them into freezing cold highly elliptical orbits.
The answer to that likely has to do with Saturn Uranus Neptune gravitationally restraining the much larger Jovian planet.
I subcribe to the Rare Earth postulate, whereby all of a large assortment of unlikely events came together 4.5-4.0 Gya that made Earth a relatively stable platform for the evolution of highly complex biological machines. Whether their is any real intelligence here on Earth remains open to debate.
Yeah we can’t even get our spelling correct.
So what scientific evidence do you have that this large assortment of events isn’t the norm, so that similar life supportable planets are all over the place.
We currently have one single observation; we are here. You can’t do any sort of statistical analysis on a single observation, so you have no basis for claiming this is a rare circumstance.
By the way; just in case you misread me, I don’t think there is anything at all special about this place; but I also do believe it is the only such inhabited place in the entire universe; not that it matters a jot, if it isn’t. And no I also don’t believe that it didn’t just happen all by itself.
g
george, the observational evidence is all the other planetary systems found to date.
They all have Jupiter or larger planets very close to their sun.
Consistent spelling is indicative of a lack of imagination.
Pretty sure Jupiter (and the other gas giants) developed closer to the Sun, then have slowly drifted out to their current positions.
“And no I also don’t believe that it didn’t just happen all by itself.” – crystal clear, got it, thanks George.
And as for it not mattering a jot if Earth is or isn’t he only inhabited place in the entire universe? Seriously? In terms of science and humanity as a whole,what could possibly matter more than that? Other than reducing CO2 emissions of course…
I’m more and more in favour of the Rare Earth theory combined with the Great Filter (being behind us, thank goodness); it is incredibly unlikely for a planet to end up with conditions we have that allow it to be suitable for life, and it is incredibly unlikely for life to begin, and incredibly unlikely for life to make the jump from prokaryote to eukaryote, and the odds of all three things happening in the same place, well, that’s a once in a universe event. Even if there is multicellular life out there, somewhere, the odds of it being intelligent – tool making, communicating, space-faring intelligent, are virtually nil, and the odds of it being close enough to us for us to actually encounter them in any way are absolutely nil. We are alone.
I think life is inevitable, as it drifts among the planets and stars. But that is a purely speculative thought, based on the odds, and the age of the Earth relative to the age of the Universe, and considering the likelihood or spores some such surviving a trip on a space faring rock, as opposed to the odds of life arising spontaneously on a planetary surface in a relatively short span that it would have needed to have done.
It may be that more stable conditions exist in nebulae or some other non-gravitationally bound environment.
The existence of extremophiles here on Earth in everyplace we have looked, including inside of solid rock miles beneath the surface, along with the numerous observations that simple meteor impacts can and regularly do blast rocks from one planet into space which eventually land on other planets and moons, and the knowledge that other sorts of catastrophic events in long ago and far away star systems gave rise to the nucleogenesis which created the atoms in our bodies which subsequently disbursed, the re-agglomerated to be here when needed, makes me think that rocks with life spores of some sort could be free floating or imbedded in dust grains, or riding on larger rocks or in ice and making similar journeys. It need not be likely or quick to have plenty of chances and time to occur in a large galaxy over 14 billion years.
The large planetismal which impacted the Earth and led to the formation of the moon was highly influential on how the Earth turned out. It may well be the case that without this impact and all the unique changes it has brought about, both in chemical composition of the crust and atmosphere, and other more subtle ways, we would not be here.
As for the late heavy bombardment being responsible for changes on Earth which somehow did not affect our neighboring worlds, how is that logical? The bolides all hit one planet with a heavy bombardment, but missed the other ones nearby?
I doubt that is how it went down, although in the case of Mars, it was likely just random chance it survived, as the body which created the moon is thought to have been roughly Mars sized. If so, this would imply that multiple Mars sized bodies existed late in the formation process of the Solar System. Since this idea of the origin of the moon implies that they were in orbits with insufficient stability to prevent crossings of two such planet sized bodies, it may be the case that other bodies of similar size were ejected from the Solar System altogether.
Of course, any ideas I or anyone else has about speculative matters such as the origins of life, the universe, the solar system or, for that matter, complex multicellular life, or even consciousness itself, stands a high chance of being completely wrong.
Any ideas which wind up being a correct description, which were dreamed up using thin evidence, are correct only by random chance, IMO.
How many of the ideas that people had a few thousand years ago have stood the test of time? Sure, the Greeks speculated that there were atoms, but how many other ideas of the structure of matter came and went and held sway since then?
How likely was it that anyone could have guessed that fire was what it was, or than there were things all around us that we could not see but nonetheless held the power of life or death over us all?
The more things change, the more they stay the same, and people have always thought they had everything pretty much all figured out.
Of course most discovered planets around other stars are huge and close to their star. Those are the planets which are easiest to detect.
Well Mark W, I don’t believe I said there weren’t any other planets. Every star could have nine of them just like Sol does.
Yep we just discovered the other day that Sol has a ninth planet called Pluto. It’s not a rock; now that we’ve had a look at it.
g
PS The “Drake equation” that proves there’s an infinity of intelligent life containing planets out there; simply forgot to include the improbability of the likely (and necessary) sequence of chemical syntheses, (that so far we have NOT been able to duplicate), that had to happen in the correct order, in the correct environmental circumstances, to get to ANY life form on Earth, let alone any intelligent form. And to date, there has been no evidence, that ” intelligence ” conveys any greater likelihood of survival, than just being big and mean and ugly like the dinosaurs.
And no, that does not lead to any conclusion of ” intelligent design ” which to me is even more improbable, than it all just happening by itself.
IMO microbes are probably common in the universe, multicellular life less so and complex macroscopic organisms even less, requiring relatively stable environments for long ages. The central region of galaxies is however unlikely to be hospitable to living things.
Life may well have developed independently on earth or could have arrived here via meteorites, which in any case are loaded with organic chemical precursors of life, as indeed is the universe at large.
Advances in understanding the origin of life have recently been made, although science may never know for sure how it occurred with high certainty at every step. The overall picture is now pretty clear, however. Further development from the earliest archaea and bacteria is however better understood, ie, the evolution of eukaryotes and multicellular organisms.
I agree Paul. Proximity to the sun is the reason Venus is much hotter than Earth and why life evolved here.
Isn’t Venus hotter than Mercury, even though Mercury is closer to the sun than Venus?
Amazing how they studiously ignore that very very obvious difference.
Venus’ atmosphere is 92 bars of pressure (Earth Sea level = ~1 bar) at the surface and the overall composition is 96% CO2 and 3% Nitrogen. Mercury has an exospheric atmosphere at 10^-15 bars, which is 42% oxygen, 29% sodium, and 22% hydrogen.
It misleading to ask the question “Isn’t Venus hotter than Mercury, even though Mercury is closer to the sun than Venus?” because you are comparing a all-but barren rock to an atmospheric rocky world.
It’s also misleading to say that any one factor (CO2 or solar radiation) is the reason that Venus is so hot because pressure and density of the atmosphere are why Venus is so hot compared to other atmospheric rocky worlds. If our atmosphere was stripped of all CO2 and then densified to the extent that Venus’ is it would exhibit similar thermal properties. The precise temperature would also be far more dependent upon the incoming solar radiation in this state than our current temperature differences – Venus would still be hotter (it needs the spot light. What can I say?)
Let’s See, Mercury effectively has no atmosphere to insulate it. Could be something there to explain why Venus is hotter than Mercury.
Holding spectrum as seen from the sun constant , the temperature of a planet is inversely proportional to the square root of its distance from the sun :
http://cosy.com/Science/AGWpptSBplanetTemps.jpg
This is basic physics which should be part of every highschool physics curriculum .
We are about 3% warmer than a gray ( flat spectrum ) body in our orbit . Venus’s surface temperature is about 225% the gray body temperature in its orbit .
There is no material spectrum which will produce a solar heat gain within an order of magnitude of that given Venus’s ~ 0.9 albedo wrt to the solar spectrum .
It’s surface temperature must be due to internal heat held in by that very radiantly insulative atmosphere .
James Hansen’s howler that Venus is an example of a “runaway greenhouse” would have caused him to be ridiculed into obscurity rather make him a climate scare millionaire if “climate science” were the functioning branch of applied physics which it ought to be .
Bob Armstrong is correct, temperature on Venus is determined by internal heat and vulcanic activity.
What? The inverse square law is still a thing? I thought they abolished that a while ago.
Along with the rest of the science I learned at school.
An increase of a few one hundredths of one percent of a trace gas will boil the oceans, broil us all alive in our potato skins, and end human civilization within a few tens to hundreds of years, based on some almost surely trivial alteration of a few watts per square meter in energy balance. But being 1/3 closer to the sun and the inverse square relationship of energy input to the planet…
Krikey!
If one looks at the ionization constants, and the effect of the solar wind in the absence of a magnetic field, and somewhat lower gravity, and other such factors…one may see that lighter elements are far more likely to be scrubbed clean out of the atmosphere on Venus. Goodbye hydrogen, so goodbye water, and the moderating influence of it.
But really, that thirty million miles makes a huge difference, as perhaps does not having an oversized moon.
How many reasons do we need?
Bob Armstrong says:
Bob, I don’t think that’s right — if it were, the IR emission from Venus would be greater than the absorbed input. I think the observed IR emission of Venus equals the calculated net solar input (solar exposure minus albedo reflection).
Can you provide any references ? Those are essential observations .
Given Venus’s half-year long night , and the assertion that it’s pre-dawn surface temperature is nearly the same as its evening temperature , I continue to be skeptical of any cause other than geothermal heating .
Unfortunately , as with many of us , to paraphrase SpiderMan , with no funding , comes no time .
Funny! …maybe as the mass of the sun decays over time, the solar wind and orbital velocity of the earth will gradually cause the earth to migrate further from the sun. In that scenario, earth would need a thicker atmosphere to slow heat loss. … and a sign that says “ice not welcome here” 🙂
I don’t see the point of the research other than it’s a pay day.
Sadly, as the mass of the sun decays over time, it will also expand in size. I think (although I have no empirical evidence to back it up, thus it remains speculation) that the suns expansion will more than overcome any orbital drift of the earth, eventually leaving us closer to the sun’s surface than we are today. Not a scenario that a thicker atmosphere will help I’m afraid. But, baring successful immortality research, none of us (nor the next million generations or so) have to worry about it. 🙂
I presume they knew every component to put into their puter model (preuming how they “played out” their story) with nothing assumed, presumed, or guest?
Alan, you presume too much. My guess is that 80% of the variables in their model were pure guesses.
There’s a 90% chance you’re correct.
There is one other key difference between Earth and Venus. On Venus there is pure science to conduct and on Earth there are political science wars and purges against fact checkers.
Yes, and one can see these science wars e.g. by no longer mentioning some very basic facts like in this quote from above:
“On Earth, shifting tectonic plates cause regular overturning of Earth’s surface, which steadily cools the underlying mantle, maintains the planet’s strong magnetic field and stimulates volcanic activity. Erupting volcanoes release greenhouse gases from deep inside the planet and regular eruptions help to maintain the habitable climate that distinguishes Earth from all other rocky planets.”
Well, and what very basic fact is missing here? Volcanoes on Earth don’t only maintain the habitable climate by releasing “greenhause gases” (primarily CO2) but maintain – first and foremost – Life itself!
Without volcanic degassing our atmosphere would lose all of its CO2 because of limestone sedimentation and other similar biological/geological processes after some 1.5 Million years. And with no CO2 in the atmosphere there would be no more photosynthesis and consequently no more Life on Earth! Never forget:
CO2 is the GAS OF LIFE !!!
You are not going to have water on and in the crust of Venus-sized planet at Venus distance from the Sun, when the rotation rate has the length of day being 116 Earth days long. The Sun is up for 2700 hours straight. Joules accumulate at the surface for 2000 hours straight. At the rate Earth’s surface accumulates joules during the day, Venus’ surface gets to 400C in the daytime. All water is baked out in the very first day.
No water in the crust, no plate tectonics, thick atmosphere, crust melts out every few 100 million years with no plate tectonics, elements capable of being released as a gas are then released, even thicker atmosphere. Energy is shared across the darkside with such a thick atmosphere. Hot Venus.
I agree with Bill. No water, no plate tectonics.
Barring some other substance that can provide viscosity in that environment, i.e. hydrocarbons on Titan.
I reckon the Moon has more to do with plate tektonics than the oceans. The crust being heaved up and down twice a day must have a hellavan impact on crustal cohesion.
R
Question – ! Okay, you know how the moon’s orbit has slowed over the eons (moon slowly farther from earth) due to tidal drag. Has the earth also moved farther from the sun? Would this explain the faint young sun paradox? Have all the planets slowly moved farther out over the millions of years? Any astronomers out there?
Technically, the tidal effects of the Moon on the Earth accelerates the Moon, thus increasing the distance between the two. Additionally the spinning of the Earth decelerates to insure an energy balance.
..
http://eclipse.gsfc.nasa.gov/SEcat5/secular.html
Thank you Joel for that bit of insight. I am embarrassed I did not see it sooner. It is so obvious now.
I read somewhere that Earth-Moon would eventually become tidally locked like Pluto-Charon, but apparently that would take far longer than the life of the Sun. Anyway, what would happen to Earth’s climate if a day were just a few hours longer? Talk about “extreme weather!”
It might be a good idea to mount giant rocket motors around the equator to ensure rotational velocity does not decline beyond some “tipping point.”
verdeviewer July 22, 2015 at 10:54 am
This is incorrect. The tides subtract energy from the earth’s rotation and add half that to the moon’s orbital energy. This slows the rotation of the earth and pushes the moon further away and slows it down. (The NASA page that calls this an “acceleration” is incompetent science writing, if we assume it isn’t just incompetent science.) However, getting back to verdeviewer’s point, the earth can push the moon all the way to infinity without the earth’s rotation slowing enough to get tidally locked to the moon. When this (never will) happen, the earth’s day would be about 55 hours long.
BTW, the other half of the energy lost by the earth is a net loss due to frictional heating. The human energy usage in the 1970s was twice that lost by tidal friction, and would be many times more now. So tidal energy is most definitely NOT “renewable”.
Early in Earth’s history, the length of a day was only about 4 to 5 hours. The rate of rotation has slowed dramatically such that it is now about 24 hours.
As the moon retreats, the length of a day will gradually increase.
The rate of rotation of a planetary body has a major impact on its conditions.
Since the Moon’s orbital velocity around the Earth slows down as it moves into a higher orbit, what is this acceleration of the moon about.
Stan Vinson
…
Before you move an object into a higher orbit, you have to accelerate it. This acceleration increase the kinetic energy of the satellite which then coverts this new kinetic energy into potential energy by moving to a higher orbit. After the acceleration it’s orbital radius increases, and it’s velocity decreases to keep the sum of kinetic and potential energy constant.
This is one reason why an elliptical orbit with high eccentricity has the orbiting object moving faster at perigee and slower at apogee.
Ron House says: “(The NASA page that calls this an “acceleration” is incompetent science writing, if we assume it isn’t just incompetent science.)
…
The NASA page is correct in calling it an acceleration.
Any time you apply a force to a mass you are “accelerating” it (Remember F=MA ? )
…
For example if you put a weight at the end of a rope, and swing it round and round to show how centripetal force works, the weight is at constant velocity, but undergoing constant acceleration to follow a curved path.
The sun has heated up over time because of the buildup of impurities (elements other than hydrogen) in the Sun, requiring higher temperatures to maintain fusion.
Wut. Obviously the Sun doesn’t create higher temperatures to get the fusion it has an ego-driven desire for. And given the stock notion you’ll see tossed around everywhere, the Sun’s heat is a consequence of fusion, not the other way around. So I’m completely baffled as to what you’re attempting to convey here.
The fusion was ignited in the core by the heat of gravitational contraction. One fusion ignited, it pushed back against the contraction, and a steady-ish state was reached, with the gravitational contraction forces balanced by the fusion heating/expansion forces.
This state will exist until the sun burns through the hydrogen in it’s core, and it’s mass will determine where in lies on the main sequence, how long it will reside there, and where, on the Hertzsprung -Russel diagram, it will go next. Our star will pass into it’s red giant phase when the hydrogen it the core is used up, and the hydrostatic equilibrium it maintained for about 8-10 billion years is disrupted. The stability of a star on the main sequence, and at a mass of the sun, is considerable. And how much energy it radiates is not a function of temperature alone, and surface brightness is not the same is core temperature in any case. The sun could be cooler, but larger, and thus deposit more energy to the Earth. The core will not get significantly hotter until the lack of hydrogen causes core contraction and helium burning commences. We will not last long when that show begins.
(On a “personal favorite” object of interest note: Just be glad we do not live a lot closer to Eta Carina, and hope that it does not produce a gamma ray burst. Wolf-Rayet stars may do, but it is uncertain in this case. It seems we are not in line with the axis of Eta Carina, but if we were, and if it did produce a gamma ray burst…even at 2700 light years, it would flash fry everyone and everything on the half of earth facing it, and could be the equivalent of a Hiroshima sized bomb on every square mile of the Earth.)
I think the sun is actually powered by gravity, which sucks. So long as you have enough mass of Hydrogen (any species), you will eventually get fusion reactions; which will stave of the gravity suction for a while.
We don’t have near enough hydrogen on earth to build a gravity suction reactor.
And the coulomb force blows instead of sucks, and that is inherently unstable.
g
I think that means nyet on earthly controlled (continuous) fusion.
“Have all the planets slowly moved farther out over the millions of years?”
According to the Nice Model, the orbits of the giant planets may have changed substantially since their formation:
https://en.wikipedia.org/wiki/Nice_model
John, the Earth has moved further from the sun over the 4.5 billion years because the sun is continually losing mass both through conversion to energy and through the solar wind. However, the effect is small, not enough to explain the young sun paradox, although every little bit helps.
Tidal effects from the sun also move the Earth away from the sun.
The tidal effect slowing the Earth’s rotation is converted by conservation of angular momentum to increasing distance between Earth and Sun. I don’t know the exact distance- the earth/moon system is separating at 1 and a half inches per day, but Lunar tides are twice as powerful as solar tides..
However I don’t know if adding this effect to the others you mention is especially significant. I’d love to see the numbers.
More modelling BS? Yep. The real world isnt 1s and 0s in silicon chips…
So the late early bombardment (or was it the early late bombardment?) kneaded our mantle, massaging it into tectonic activity. Extraordinary speculations need extraordinary evidence. Of course, there is none, but fun to think about nonetheless.
Neat idea… but wouldn’t uranium (and any other heavy radionuclides) sink to the middle of a molten earth?
Yeah, the potassium would float, but only potassium 40 has a reasonably long half life, and unless we detected huge outgassing of argon from the Moon or certain asteroids, I’d say that we still have most of our potassium 40.
Indeed, that’s where most of the earth’s uranium inventory is located. Radioactive decay is what’s kept the earth’s core liquid for the past 4.5 billion years.
Ah, see now, this is part of the problem of modern science that is rife throughout things like Climastrology. We have estimated the age of the universe on the basis of various things, none of which are testable as such. And from that we’ve stated what the temperature of the Earth should be, which it isn’t. From which we estimate the amount of radioactive product that must be in the inaccessible and untestable Deep Earth (Hansen call your office.) From which we then state that since the Earth contains an estimate of whatever quantity of radioactive whatevers, therefore the age of the universe is… Each of the estimates is used to correct each of the other estimates such that they all hang together consistently. But calling it an ‘estimate’ is a little optimistic. As we certainly aren’t validating any of these things.
The consequences of which are statements such as: The Moon has no molten core, it’s too old. And then, surprise, it in fact does. Not much of one mind, but there you have it.
Lets do ourselves and the integrity of Science a favor. It’s not a ‘fact’ unless you can, and multiple people have, demonstrated it with experiments. Not estimates, experiments. And let’s ensure that a chain of provenance is always kept for all things. If P is clobbered together out of some idea of Q, then we cannot turn around and correct Q on the basis of P. As that’s just correcting Q on the basis of itself.
This question was debated starting in the 19th century. Stored radiation of heat would long since have produced a much smaller core with a much thicker crust. Radioactive decay explained how the earth’s core retained its high temperature and much larger volume that would otherwise be the case. And this statement:
“We have estimated the age of the universe on the basis of various things, none of which are testable as such”
is simply incorrecdt. Of course they’re testable. And they have been tested by observation. The problem is that the different observations conflict.
cgh:
This only follows if we already know the age of the universe, or some minimum bound on it’s youth.
Yes, I’m perfectly well aware that there’s a fondness about for calling an ‘observation’ a ‘test.’ But that hardly makes it so and why I said ‘testable as such.’ Consider one of the key notions around sorting out cranks from science. It is common for cranks to let you observe their over unity energy machine, but not test it. You may look, but you may not touch. You may observe, but you may not test.
Different observations can hardly conflict with one another. They simply are. However, any one or more observations can conflict with a given theory. If there were no errors in the observation or its interpretation, then the only error is the theory itself. Until you sort this out, the rest of your education in the Scientific Method will need to wait.
Well why would the Uranium sink to the bottom ?? After all, the gravity at the center of the earth is zero, not some huge number that attracts heavy stuff. The deeper you go, the lower that gravity gets. So nothing is crushing anything, at the earth’s center.
g
“Well why would the Uranium sink to the bottom ?? After all, the gravity at the center of the earth is zero, not some huge number that attracts heavy stuff. The deeper you go, the lower that gravity gets. So nothing is crushing anything, at the earth’s center.”
This is just wrong! This is like saying that a submarine at neutral buoyancy can go as deep as it wants in the ocean and not have to worry about being crushed. There may be no net gravitational force at the center of the earth, but you still have the weight of 3,500 miles of rock pressing down on you from all sides even tough you yourself are floating weightless.
george e. smith said “Well why would the Uranium sink to the bottom ?? After all, the gravity at the center of the earth is zero” .
But the gradient is maximal .
Time for a REAL SAVE THE PLANET! movement. Earth don’t need it; Venus does.
Could Ceres be put on a collision course with Venus at just the right trajectory to put some spin on her?
First we will need to drill the three big finger holes.
When the global warming scare first came to light, I believed it until some “scientist” said that if we did not stop burning fossil fuels Earth would end up like Venus because of the amount of CO2 in the atmosphere. This did cause me some worry until i decided to check it for myself.
“The density of the air at the surface is 67 kg/m3, which is 6.5% that of liquid water on Earth. The pressure found on Venus’s surface is high enough that the carbon dioxide is technically no longer a gas, but a supercritical fluid.” Wikipedia,
I realised that if temperatures increased so much that CO2 was lost from the oceans and limestone broke down to CaO and CO2 (which only happens at 848 Celsius anyway!) there would be a problem, until I then thought that all this CO2 was in the atmosphere in the first place and that did not cause Armageddon!
The whole AGW “theory” (in my view it is only a hypothesis) must be wrong! If I am missing something here, I would be grateful, if someone could let me know
Venus is hotter than Earth due to more mass in the atmosphere.
The evidence is that after adjusting for distance from the sun the atmospheric temperature is similar to that of Earth at the same pressure.
Exactly so.
Show me the equations .
“The only respite from the heat on Venus is to be found around 50 km into the atmosphere. It is at that point that temperatures and atmospheric pressure are equal to that of Earth’s”
from here:
http://www.universetoday.com/14306/temperature-of-venus/
but they don’t appreciate the implications of that fact.
and although this article:
http://www.datasync.com/~rsf1/vel/1918vpt.htm
discusses the viability of viruses on Venus it does show some relevant charts.
Although I don’t agree with Harry Dale Huffman on many matters he is dead right on this:
http://theendofthemystery.blogspot.co.uk/2010/11/venus-no-greenhouse-effect.html
Stephen , I know that it is claimed that at some height in the Venusian atmosphere the observations apparently match Earth . But I want to understand it . And for me that requires being able to compute it — which for me means to express the relationships succinctly in an APL ( at this point , my own 4th.CoSy ) .
Thus , to me , it remains just an interesting observation until I see and understand the equations and can derive it quantitatively to observational accuracy .
The classical quantitative relationships I assert have been and can be experimentally demonstrated and should be in any highschool physics curriculum .
I also disagree with Harry on the absorption / convection aspect but that does not detract from the calculation he presents.
Bob,
Stephen and Harry are just confusing themselves. The mean temperature at the 1 bar level in the Venusian atmosphere is ~339K. On Earth, the equivalent temperature (at the surface, at 1 bar) is 288K.
http://www.datasync.com/~rsf1/vel/1918-4a.gif
http://www.datasync.com/~rsf1/vel/1918-3b.gif
Yes, Venus is closer to the Sun, but it still absorbs a lot less solar energy as heat than what Earth does: 163 W/m2 vs. 239 W/m2. What Stephen and Harry leaves out is simply global albedo – Venus: 0.75, Earth: 0.3.
So Venus is hotter than the Earth by 51 degrees at the same atmospheric pressure level, even though it receives only 68.2% of its heat from the Sun. Go figure!
Kristian,
The albedo difference and the insolation difference are both dealt with by convective adjustments within the atmospheres which is why the ratios noted by Harry (and the ‘old’ pre radiation theory science) still apply to those planets with atmospheres where we have been able to ascertain the vertical temperature profile.
http://www.public.asu.edu/~hhuang38/mae578_lecture_06.pdf
“Radiative equilibrium
profile could be unstable;
convection restores it
to stability (or neutrality)”
Kristian , Thanks for the data ; Hockey has supplied critical equations . The temperature curve I would believe is the one that turns back towards the 328k equilibrium temperature of a gray ball ( flat spectrum ) in Venus’s orbit . That’s simply the temperature related by the StefanBoltzmann equation to the total energy impinging on a point in the orbit . Any difference from that from that as one descends in the atmosphere then is attributable to the absorption=emission spectrum of that atmosphere .
And the minimum of the curve would indicate that Venus is substantially more absorptive=emissive in the IR than its extreme albedo with respect to the solar spectrum .
However , the 184.5 or whatever NASA misleadingly labels Venus’s “black body” temperature is a useless inexcusably crude step-function approximation assuming Venus’s absorption=emission spectrum jumps to 1.0 at longer wavelengths . This is inexcusable when I am sure far more accurate measurements of Venus’s full spectrum are available . The fact that the atmosphere is apparently transparent at radar frequencies shows it’s not simply opaque black . At those frequencies , it is the absorptivity=emissivity of the surface which matters .
These emendations may seem small , but the total variation this statist useful hysteria is about is on the order of the 4th decimal place , a few 10s of a percent . There is no way you will ever understand such small phenomena if stuck on 2 digit crude ( and biased ) approximations when data are , or should be , available .
Stephen Wilde July 24, 2015 at 1:27 am
“The albedo difference and the insolation difference are both dealt with by convective adjustments within the atmospheres which is why the ratios noted by Harry (and the ‘old’ pre radiation theory science) still apply to those planets with atmospheres where we have been able to ascertain the vertical temperature profile.”
Er, no. Of course it isn’t “dealt with”. It is completely ignored. If it’s “dealt with”, that is, included, there is no fit, and hence Huffman’s great “discovery” is shown to be nothing more than an expression of the man’s profound confirmation bias.
What else is new? My new post:
“Convection Is Instability and Does Not Rule”
How do the computer models factor in the effect that the lack of a magnetic flux, which would shield Venus from the solar winds striping away the Hydrogen and Oxygen and other gases from the higher atmosphere? Why is the fact that Venus has no magnetic flux never addressed in the feeble AGW explanations justifying the effect that CO2 has on the Earths temperature based upon the Temperature on Venus?
Mustread: Bullock & Grinspoon, The recent evolution of climate on Venus, Icarus 150 (1) 19-37
http://www.boulder.swri.edu/~bullock/Homedocs/vclime.pdf
Well, that’s a massive house of cards.
Ancient astronomers and ancient oral histories from around the world — in areas and cultures that had zero interaction — all describe Venus as a stupendous comet.
Ironically, the best math teacher I had was very much into Velikovsky. I would have liked to have been in the teacher’s room when he ran into the best history teacher I ever had, and who had, shall we say, another opinion on Velikovsky.
well even a broken clock can be right twice a day. therefore it’s not out of the realm of possibility that velikovsky could be right once in his lifetime.
I think that our moon is the reason why Earth is unlike Venus. But that’s a long story involving:
http://www.imcce.fr/Equipes/ASD/preprints/prep.2002/venus1.2002.pdf
and a few more thoughts that the authors missed.
The “scientists” crafted a very nice creation story. What religion are they doing this for?
By the way, I can’t find anyplace where gravity and the mass of the earth’s atmosphere vs. the same on Venus are mentioned. Really? The weight of the atmosphere makes no difference?
“Erupting volcanoes release greenhouse gases from deep inside the planet and regular eruptions help to maintain the habitable climate”
Well, there goes any chance of them scoring a follow-on grant for further study.
I highly recommend the book Rare Earth: Why Complex Life Is Uncommon in the Universe (2000), by Peter Ward, Donald E. Brownlee.
It’s thesis is that simple forms of life may be quite common in the universe, but the development of Complex Life, not necessarily intelligent life, is probably much rarer than we thought just a couple decades ago.
The first argument, that simple life is that we have found simple life forms is some incredibly hostile environments such as deep sea volcanic vents that depend upon chemosysthesis. We have found bacteria inside rocks such as shales. Extremophiles that live in hot springs. Such discoveries make the finding of single cellular life on other bodies in just our own solar system a real possibility worth scientific investigation.
But the study of astronomy, astrophysics, paleontology, geology, biology, also lead to the conclusion that the condition that allowed the development of trees, dry land on a waterly planet, and animal life require conditions very unlikely to develop.
Most of the galaxy is hostile to life. A planet needs to be in a stable orbit around a stable star, in the “habitable zone”. The planet needs to have plate tectonics. It needs to be sufficiently large to retain an atmosphere, yet not so large that it becomes a gas giant. A large moon helps the planet maintain a stable axis with mild seasons. A rapid day-night cycle helps. You need all this stable enough for evolution to do its job. Rare conditions indeed.
In an infinite universe, everything is not only possible, but likely.
Hitchhiker’s guide to the galaxy.
Think about it. The attraction between protons and electrons and all fundamental particles has to be just “right” for matter to exist. What are the chances of that happening? The multiverse concept is very likely true.
So, I would expect there to be many thousands of worlds with complex life in our galaxy. Not intelligent life as we understand it (human). Intelligence is highly over-rated and, as we have seen, soon leads to self-destruction through technology.
Or through politics.
Sir Fred Hoyle and The Beryllium Bottleneck.
” as we have seen, soon leads to self-destruction through technology”
Actually, we haven’t seen that.
100% otherwise you wouldnt be here to ask that question
With untold billions of suns in our galaxy, with billions of galaxies, my thoughts would be that Earth like planets abound.
That depends on what you mean by “Earth-like”.
Earth-like in Mass? certainly
Earth-like in Habitable zone? yes many.
Earth-like in a stable orbit? Well that rules out half the galaxy.
Closer to the core the density of the stars make it a sure thing that one will pass close enough to another to jiggle the harmonics of any once-stable planetary system. One close encounter every 100 million years and you get repeated mass extinction events. We have survived a couple of them — the end of the Permian was a close call and it *probably* wasn’t a close encounter with a stellar neighbor.
So Earth like in Mass AND in a Habitable zone FOR a billion years…. The odds are getting longer.
Mind you, none of the previous condition preclude simple life. As Michael Crichton wrote: “Life will find a way.” Who knows what lie beneath the ice of Europa? The color bands of Jupiter may owe some of their existence to the biological waste products of scores of genus of simple life creatures.
Complex life, on the other hand, takes time for evolution to do its work. It need a place without gamma-ray bursts, solar variability, and dozen other environmentally hazardous astrophysical influences to destroy the handiwork of evolution.
There is a well known calculation multiplying each of the mentioned requirements (or what we might suppose are requirements) and then calculating the number of systems that have earth-like planets.
The final number is large.
The question then, now, has become: If this is true, then where the heck is everybody?
Funny thing about questions…until one knows the answer, one really has no idea whether they are even good questions, much less what the answers will turn out to be.
Our assumptions may be wrong, or we may just be less important than we think…or, there is no such thing as a warp drive engine, and space and time are very big…VERY BIG.
That may be the only real answer we need.
What hope does an earthworm in London have of finding a mole cricket in Indonesia?
Maybe so. Doesn’t mean ANY of those billions have life. Life is as improbable, as the number of earthlike planets is huge. Zero times infinity can still be zero. (or anything else).
The biggest difference by far that is the main reason is Earth 1 atm, Venus 90 atm. Mentioned earlier at 1 atm on Venus the temperature is similar to Earth.
Asteroid bombardment, bombschmardment. The thing is we both got hit very early on by Mars-sized planetesimals but we took a glancing blow which actually spun us the right way and gave us a nice big fat moon, whereas Venus ended up spinning the wrong way. Hell on Venus followed from there.
Pointman
Interesting. Is Earth the only planet in the solar system that spins “the right way?”
It’s not the “handedness” but the speed of revolution. How many hours long was the day in the Mesozoic era and what was already the effect of it? What will eventually happen to our spin and why? Follow up question, what happens when you spin up an iron core?
Pointman
Now here’s where probability and statistics come in handy: what are the chances that a collision would stop Venus dead in its tracks? or just a tiny bit backwards? or with resonance with the earth’s orbit? It seems almost as Velilkovskian as claiming a serendipitously circular orbit. Isn’t it more likely that a Venusian ocean or atmosphere slowed it down and stopped it, with the help of a big solar tide? –AGF
Reading skills Mr Foster, we’re not talking orbit here but spin, but I rather think you’re doing the modern version of spin in wilfully misinterpreting my comments. Velikovsky, who a low blow. Cicero: “If you don’t have a good argument, attack the plaintiff”.
Pointman
What the hell do you think I’m talking about? Resonance with the earth’s orbit? 3:2? That’s rotation. Rotation! And don’t take it so personal–I know you’re just spouting the consensus. But it’s a statistically incompetent consensus. The tides have to be invoked even with the questionable collision hypothesis–it’s a matter of degree. Since the history of the Venusian atmosphere and possible ocean is unknown, the collision hypothesis is an unneeded complication, not capable in itself of solving the problem. Do you think Mercury also slowed down via collision? –AGF
Why would statistics tell you anything about something that may not have happened at all, let alone enough times to get a good statistical sample to analyze.
g
The article/link below is intended to support the theory of “Intelligent Design”.
Whether you believe in that theory or not, it’s mind boggling to think about the hundreds of factors, many that are extraordinarily rare, that had to be just right for us to be here, reading and posting on WUWT at this moment.
http://www.godandscience.org/apologetics/designss.html
What would be the equivalent odds of flipping a coin and getting consecutive heads for instance?
Something on the order of flipping 1,000 consecutive heads, which has odds of 1:2(1,000th power) or ~1:10(301th power)
The actual number/odds for the coin flipping to heads 1,000 times in a row is: 1:
10715086071862673209 484250490600018105614 0481170553360744375 038837035105112493 612249319837881569 585812759467291755 314682518714528569 231404359845775746 985748039345677748 242309854210746050 623711418779541821 530464749835819412 6739876755916554394 607706291457119647 768654216766042983165 2624386837205668069376
………….of course that probability could be much less or much greater since we don’t have enough information to accurately estimate the statistical odds for the occurrence of most factors………but you get the point.
The multiverse concept seems very attractive.
Not to me. What are the odds we would be in the right universe of the multiverse?
About the same as the random chance of us being here in the one single universe?
Inventing something that there is no proof of, no way to test for, and that solves nothing is a lazy man’s way out of wondering about things, IMO.
Why wonder about it if the answer one settles on, is the sophistry ad hoc explanations, or of deciding all things are equally possible, so everything is inevitable?
Why ??
Intelligent design is not a legitimate theory. It is an attempt to sneak creationism into schools through the pretend science back door, as found by Delaware courts.It is fully debunked as a misunderstanding and misapplication of evolutionary principles. Used the eye as the ID example in ebook The Arts of Truth.
Yes and no. We cannot state that Intelligent Design is not appropriate to Science, nor that it’s not being used by science. At present Monsanto intelligently designs organisms every day. Likewise, forensic genetics are used routinely in biowarfare programs to highlight whether or not a given strain of a pathogen was intelligently designed or not.
What we can state is that because we can show intelligent design, it does not follow that all organisms were designed through all time. But the same problem adheres to the current consensus theory of Evolution. For we can show random mutations currently. But that hardly means that we can show that all organisms were constructed by random mutations through all time.
The problem here is not the current experimental results and engineering practices. It is the origin myths themselves. But as both origin myths have the same argument in favor, and the same epistemic veracity, then we cannot call one an issue of religious creation myth, but not the other. Either neither is, and so both can and should be taught. Or both are, and so neither should be taught on the public dime in nations such as the USA.
So if the universe has expanded and then contracted 10715086071862673209 484250490600018105614 0481170553360744375 038837035105112493 612249319837881569 585812759467291755 314682518714528569 231404359845775746 985748039345677748 242309854210746050 623711418779541821 530464749835819412 6739876755916554394 607706291457119647 768654216766042983165 2624386837205668069376 times, it would only take one of those expansions to be right for intelligent life to evolve and contemplate the question. The next question is: which expansion are we in?
The one we’re in.
The current one. Which is the only one that maters, and the only one we know for sure is not a figment of someone’s imagination, The Matrix notwithstanding.
The United States has 600,000 doctors to deal with the problems of its Intelligently Designed humans. Some intelligence.
I find it interesting that Mars appears to have had it’s surface scarred and partially ripped away by plasma arcing. Was it once like Earth before a close encounter with a charged object?
http://www.plasmacosmology.net/scars.html
It seems as time goes by we find less and less similarities in the individual planetary “experiences” over the aeons while sharing a common heliosphere.
I choose to believe Mars had an earth like environment before the Martians fought a huge planetary war with weapons that make our nukes look like fireworks. ○¿●
Is it just me or do others find that running models and drawing conclusions about an uranium/potassium stripping impact event without any actual observations other than: ” the layer that should have been there isn’t” can’t be classified as “science” much more than a group of guys sitting on the sofa passing a bong and one saying to the others: “yea man what if elephants could fly” Wow man.
It’s not just you. But, hey, in brings in the paycheck.
+1
These articles about how Venus came to be what we see today are garbage. They first of all ignore the widespread, global reports by pagans that Venus arrived in human-historical times as a comet (the feminine attribute derives directly from the comet’s hair). But, far worse than that, there is NEVER ANY MENTION OF THE FACT THAT THE VENUS PIONEER DATA WAS CORRECTED TO REFLECT A GREENHOUSE WARMING HYPOTHESIS.
See original snapshots at https://plus.google.com/108466508041843226480/posts/hKf2QRETTAy.
The only people talking about this are the plasma cosmology folks, so please realize that there’s a price to pay for filtering out their own posts on this site.
Even Plato is clear that a human-historical catastrophe occurred …
From Plato’s Dialogues at https://books.google.com/books?id=6IJEAAAAIAAJ&pg=PA367&lpg=PA367
“Phaethon, the son of Helios, having yoked the steeds in his father’s chariot, because he was not able to drive them in the path of his father, burned up all that was upon the earth, and was himself destroyed by a thunderbolt. Now, this has the form of a myth, but really signifies a declination of the bodies moving around the earth and in the heavens, and a great conflagration of things upon the earth recurring at long intervals of time”
(Notice that Plato is unwittingly describing a debris field that would regularly return to the earth after an initial catastrophe — even though Plato has no idea what gravity or a debris field actually is …)
And, to make sure that everybody understands the meaning of the ancient myths, he further states:
“All of these stories, and ten thousand others which are still more wonderful, have a common origin; many of them have been lost in the lapse of ages, or exist only as fragments; but the origin of them is what no one has told”
I don’t know how Plato could be any clearer:
The myths all originated with a planetary-scale catastrophe.
You’re supposed to put “sarc:)” or something like that. But we know you can’t be serious. –AGF
The collision which created the moon wiped out about 3/4 of Earth’s atmosphere. The lower surface pressure resulted in lower temperatures, and allowed liquid water. CO2 dissolved in the oceans and formed carbonates, further lowering the atmospheric pressure. The Earth also gets half the sunlight received by Venus. All of these factors combine to make Earth a lot different from Venus.
I guess you just cannot get attention nowadays without some sort of “OMG things COULD be so WORSE” …
Funny thing with Venus is, everyone is told that it is much hotter than Earth thanks to double solar irradiance and hellish greenhouse effect. Whereas in fact, because of its 0.9 albedo, Venus has (according to NASA’s “venus fact sheet”) a blackbody temperature 70 K LOWER than Earth (184 K Vs 254). It is horribly COLD (not hot !) out there.
I wonder …
Is it not because it is so cold, that atmosphere is so heavy, making surface so hot ?
funny paradox, if true. what you think ?
More scientific rationale for Rare Earth. Rare Earth at least partially explains why most of the “evidence” of Extra Terrestrial Advanced Lifeforms is found on the likes of “Coast to Coast AM.”
This hypothesis is based on the belief that the Earth was subjected to a greater bombardment than was Venus. The objects involved in the bombardment would have been in orbit around the Sun and as Venus is so much closer to the Sun than the Earth is, I can see no scenario where the Earth would have been impacted more heavily.
There is support here for the proposition that the heat at the surface of Venus is attributable to atmospheric mass held within a gravitational field and irradiated by an external source.
Yet I have been involved in many arguments here when regular contributors argued to the effect that it is not atmospheric mass which causes planetary surface temperatures to rise above S-B.
Interesting.
I am getting ready to disappear in a cloud of blue steam. ( No apologies to Hansen)
It also seems strange to me that the “rocky” planets were originally and always “rocky” planets. Since all planets were supposedly made from an accumulation of the matter in the disk around the Sun, WHY would the inner planets NOT also have originated by all of the matter in the position in the disc that they were located? Thus all planets would have been gaseous at first, and then, over billions of years the inner planets would have lost large portions of their gases making up the planets and leaving a “rocky” planet.
maybe the gravitational attraction of the sun ensured that more dust & rocks moved to the inner parts of the disk, then formed rocky planets, while most of the lighter gases stayed in the outer portion & became the gas giants?
The Rocky planets are much better than the Apollo Creed planets. Ask anyone.
Personally I think that the only relevant unlikely event in the Earth’s history is the collision that bound the moon. That collision would have completely altered the composition of the Earth, and IMO probably took a large fraction of the early atmosphere of the Earth off with it.
It is this atmosphere that really differentiates the Earth and Venus. The atmosphere of Venus has a surface pressure of 90 atmospheres. The outermost portion of that atmosphere has to radiate as much energy as it receives, which determines the temperature, more or less, at its cloud tops. As a result of this high density (and its composition, mostly CO_2) the troposphere on Venus extends all the way to 65 km, roughly 10x higher than Earth’s, and it has to be balanced at a proportionally higher greybody temperature at the cloud tops since there is basically no direct radiation loss from the surface. There is no stratosphere on Venus — it goes straight to the mesosphere.
The lapse rate, OTOH, continues all the way to 100 km — 10x that of the Earth — and drops temperatures from over 700 K to under 200 K before turning over, where the Earth has a stratosphere that warms from a minimum temperature well above 200 K before dropping again in the Mesosphere and warming again (irrelevantly) in the thermosphere.
IMO the only reason Venus isn’t conducive to life is that it has way, way too much atmosphere, and tends to lose both O2 and N2 before either one can build up into an atmosphere like Earth’s with CO_2 constantly recycled into bound carbon and oxygen. I agree with the top article that the magnetic properties are important as well — having a strong magnetic field definitely alters the way the solar wind strips off atmosphere at the very top as well as protects the surface from excessive radiation — and suspect that this too is related to the moon-forming collision and its aftermath as much as anything else — but I’d bet “life would find a way” if somebody stripped Venus of 90% of its existing CO_2, allowing it to develop a stratosphere and cooling the surface to where liquid water might accumulate at least at the poles. It might help to take e.g. Europa and drop it onto Venus and wait a billion or so years and see what happened, or to scavenge a dwarf-planet’s worth of large (> 10 km) comets from the Oort cloud and drop them all onto Venus one at a time, blowing away most of its existing atmosphere and releasing a huge cloud of free water to reflect heat away with its high albedo until the surface had time to cool to the greatly reduced ALR to the much lower tropopause.
But we needn’t worry about the Earth becoming “like Venus” unless and until we could increase the total mass in our atmosphere by an order of magnitude or more, and there simply isn’t the raw material or any reasonable process that is going to make that happen.
rgb
rgbatduke said:
“But we needn’t worry about the Earth becoming “like Venus” unless and until we could increase the total mass in our atmosphere by an order of magnitude or more, ”
So is it mass that makes the Earth’s surface 33K warmer than S-B ?
S-B is predicated on unobtanium by design. It is used as a mathematically and existentially ‘pure’ starting point for the rest. And for which if we find anything that violates S-B, then we know that Thermodynamics is as bunk as Phlogistons.
To claim that the Earth is 33K warmer than S-B requires that you give up at least one of:
1) Thermodynamics
2) The propriety of the model for charateristic temperature of a sphere orbiting an (effictively) point souce.
3) The propriety of the model for determining the average temperature of Earth.
Jquip , That 33k number is meaningless red herring useless in any computation . It is not the temperature of a grey , flat spectrum body in our orbit and it obscures the important fact that a gray ball , no matter how light or dark , comes to the same equilibrium temperature , about 278.6 +- ~ 2.3 degrees from peri- to ap- helion , Any difference in temperature is proportional to the 4th roof of the ratio of absorptivity=emissivity wrt the sun’s spectrum , and absorptivity=emissivity wrt the insignificant thermal spectrum of the rest of the celestial sphere . See http://cosy.com/Science/HeartlandBasicBasics.html for the computations including the assumptions creating the irrelevant 33k meme .
Jquip
The Earth’s surface is warmer than the S-B equation predicts but the Earth as a whole when viewed from space is not.
The difference (whether it be 33K or some other figure) is accounted for by surface kinetic energy locked into convective overturning which maintains the hydrostatic balance of the atmosphere as here:
http://www.public.asu.edu/~hhuang38/mae578_lecture_06.pdf
Thus:
“Radiative equilibrium
profile could be unstable;
convection restores it
to stability (or neutrality)”
The convective adjustment occurs without a change in surface temperature unless there is increased TOA insolation or a greater portion of TOA insolation reaching the surface provided atmospheric mass and the strength of the gravitational field remain constant.
Stephen , thanks for the link . I’ve bookmarked it .
So you’ve given up 3). No worries, keep it under your hat as a challenge to others that haven’t thought about the issue.
Why dont we paint a basketball the right color gray and put thermometer on it and launch it into space and make it rotate once every 24 hours? Then we can once and for all measure what temp the earth should be with out an atmosphere.
Bob , see my comment at July 22, 2015 at 9:49 am . This physics is older than relativity and was abstracted from broad experimentation in the 19th century . It is certainly no more difficult than the high school PSSC physics I had half a century ago .
But it would be extremely therapeutic to see it replicated today . It is clear that many posting here , much less any alarmist blog , have never learned even these most basic non-optional equations .
It would be useful to demonstrate them in both the brilliantly simple and affordable manner of the PSSC curriculum and most spectacularly by sticking well spectrally calibrated ball out the window of the space station . ( I don’t understand why engineers in satellite heat budgeting are not more active in these debates . )
When I moved from Manhattan to Colorado , the first thing I did becoming active in this battle for rationality was a “Mr Wizard” style experiment with painted ping-pong balls , http://cosy.com/Science/warm.htm#PingPong , to confirm my , literally childhood , sense of the most essential physics wasn’t just nuts .
It makes it 33 warmer than the greybody temperature, which is not exactly S-B. It isn’t “mass” per se that does it, either — it is atmospheric density, the adiabatic lapse rate, and greenhouse gases all working together that does it. But I’ve explained this maybe four times on two or three different threads in the last couple of days on WUWT and I don’t have the energy to explain it again on yet another thread.
rgb
RGB , we are about 10 degrees warmer than the 278.6 of a gray , flat spectrum ball in our orbit . That is the only number useful in computations .
The 33 degree number is produced by a crude unjustifiable hypothetical step function spectrum assuming a average absorptivity=emissivity of 0.7 over the bulk of the solar spectrum , but an absorptivity=emissivity of 1.0 ( black ) over the longer wavelengths . Here’s a plot showing the computations :
http://cosy.com/Science/AGWpptHypotheticalSpectra.jpg
The 95% of the missing universe is not dark matter, it is charge, the recycling of charge from the sun enters from the poles. It discharges from the equator in the band +30 to -30 degrees north and south. This is the Earths internal heat. It is also the missing part of the puzzle in physics besides the missing part of the universe.
Well I don’t know what a S-B gray body spectrum or Temperature is, I only know what a fictitious BB spectrum or Temperature is, and incidently that BB is required to be isothermal, which it cannot be, unless it has infinite thermal conductivity as well.
So calculating what earth’s Temperature is “supposed” to be is an exercise in futility.
The Temperature of the earth is at all times, exactly what it is supposed to be; no more, and no less.
g
By Kirchhoff ( & Stewart , building on Ritchie’s experiment ) the temperature of a gray , ie : flat spectrum , body , no matter how dark or light , will come to the same temperature as a black body — which simply calculated by summing all the radiant energy impinging on it .
That simple minimal computation explains 97% of our estimated temperature .
There’s a reasonable quantity of CaCO3 which at one time would have contributed a significant amount of CO2 in the Earth’s atmosphere
This article is basically bunk because it deals with plate tectonics as if the plates were floating around on an Earth of constant diameter. It has been conclusively proved that the Earth is expanding in diameter.
Websearch You Tube for videos on “expanding Earth” and you will see that the Earth’s sea bottoms contain very precise measurements of Pangea’s expansion through sea-floor spreading over time, including the directions of the spread.
Whaaaa…?
I suppose they missed the part about subduction on the opposite margins of the plates.
Apropos of not very much at all, this reminds me of a question in my first year maths exam at uni which went very much as follows: “Assuming (if this were possible) that the Earth instantaneously disappeared from the solar system at some point of time, what would then happen to the Moon”? Answer – the Moon would wobble for a while about at first, but soon settle down into (effectively) exactly the same orbit as that of the (former) Earth. So: Earth and Moon are really dual planets, rotating about one another and, together jointly, about the Sun.
But Earth and Moon of course have very different climates and, yes of course, Earth is a pretty habitable place. How did we get so lucky? For myself I’d say essentially pure chance: but with enough stellar systems in the universe thankfully it had to happen somewhere. But I very much doubt we can be the only ones …
To my knowledge no one has contested Émile Clapeyron’s pV = nRT. Because AGW cult seems to upscale laboratory experiments to planetary scale as a standard procedure, how much carbon homo sapiens should theoretically burn to even approach Venus-like temperatures on Earth?
PS. Because carbon is 4th most common chemical element in the our Galaxy and only the 15th on Earth (by mass), we may need Scott to beam Kranken Mare here for the project.
From the University of British Columbia: lucky … evolutionary path … early in its history … early loss … evolution … early formation … create the Earth … events … differentiate Earth … over geological time … evolved so differently … billion-year-long swings … initial composition of a planet … evolution … circumstances that make Earth.”
Is there some reason to actually believe that the early bombardments of Earth and Venus were quantitatively different other than hypothesizing it was so makes their desired result?
I’m getting the faint whiff of models here.
“Venus is in a climate catastrophe”
Seriously?
Catastrophe to who? Who’s suffering?
Venus is what it is.
Is Mars in a climate catastrophe, too?
Follow up:
Was Earth in a climate catastrophe when it was putatively stripped of 3/4 of its atmosphere? You would think so. Or did that solve the putatively existing climate catastrophe?
What’s the opposite of “be careful what you wish for”? “Be grateful what you didn’t wish for”?
Yes, Mars is in a major catastrophe. According to NASA it contains 30 times more CO2-ice than initially presumed. It has major difficulty kick-starting positive feedback loops.
Correction; we Skeptics live on planet Earth. Hard to say what planet (or even universe) Warmists live on.
It appears to be a restatement of the theory that Venus has periodically resurfaced itself volcanically. This is obvious to practitioners of science since Venus has no craters, or very few, compared to most of the moons and planets and asteroids in the Solar System.
In this case, the “impact erosion” knocked off the layer of earth which would have made it resurface itself with planet-wide volcanic floods, just like Venus:
They could be getting a little closer to the truth when they say that some of earth’s crust has been partly lofted into space. It would not surprise me if an occasional meteorite was actually a terrestrial rock returning to us; rocks from Mars are collected from Antarctica all of the time.
It is not really a very peaceful neighborhood here. You can make all the rules and models you want but the sun and asteroids are not always going to obey them.
This little bombardment knocked off the crust
This little bombardment deposited the ocean water
This little bombardment cleared the stage for mammals
And now we are all snug and safe except for the ghgs from agriculture, cattle, and personal transportation.
Not to mention the Squidgy Bombardment, which, in the Nebular Hypothesis, assembled the planets in the first place.
Venus, with a considerably denser atmosphere, incoming meteors/comets would get burnt up far more than they do here on planet Earth (or on the moon that has no atmosphere).
It may well be the case that most incoming material gets burnt up,, or breaks up into smaller parts so one may well not expect to see as much in the way of impact craters on Venus.
So it could well be the case that the lack of impact craters is not evidence for volcanic replenishment of the surface.
Where do they get these people????
Venus is the way it is because it has 96 times more atmosphere than Earth. The composition of that atmosphere is irrelevant! The ‘work’ done on that mass by gravity raises both the pressure and temperature of its atmosphere at its solid surface. This is standard physics. No other fairy tale explanation is needed. No greenhouse effect. Why is this so hard to understand?
Because it’s wrong!
Show me your equations .
See
“Don’t Tell the Experts”
and the original 2010 article
“Venus: No Greenhouse Effect”
I don’t see anything other than the most basic Stefan-Boltzmann relationship which will produce the 328k gray body temperature in Venus’s orbit . I don’t even see the equations for the dependence of radiative balance on spectrum ( color ) .
I see no equations for any additional parameters .
Bob,
What additional parameters do you need and why ?
The observed, measured ratio is enough to make the point is it not ?
Any of those factors which are a function of radius .
Dear Moderator, this comment seems to have been lost?
hockeyschtick Your comment is awaiting moderation.
July 22, 2015 at 7:19 pm
No, it is not wrong. Mathematical derivation of equations which perfectly describe temperature profiles of Earth, Venus, Triton, & all other planets in our solar system with thick atmospheres:
http://hockeyschtick.blogspot.com/2015/07/new-paper-finds-increased-co2-or.html
Same basic atmospheric physics were used to calculate the 1976 US Standard Atmosphere, without one single radiative transfer calculation, and entirely on the basis of mass/gravity/pressure/density. Trace CO2 was completely discarded from their model since it was determined to have negligible effect.
http://hockeyschtick.blogspot.com/search?q=1976+US+Standard+Atmosphere
I’ll have to study your links . While clearly there is a gravitational energy well to a planet , it intuitively seems far too little to account for the temperature gradient of Venus . In deed , Venus and Earth are very different in the manner in which they are heated . The Earth is , of course heated from the surface causing strong convection . Only about 3% of impinging solar energy reaches Venus’s surface . Thus in a first approximation the effective surface at which radiative balance between its spectrum as seen from the outside and that of the sun is high in the very reflective clouds . Within that boundary the divergence theorem says average energy density will match that calculated for that surface .
Unfortunately it will be some time before I look at these equations because my priority is bringing my open 4th.CoSy APL informed vocabulary in Forth to the point where I can express your equations as succinctly as you have written them so they will run on arbitrary data on any current or future hardware .
Incidentally , Alan Guth has a brief but convincing explanation of why gravity is a negative energy in a short appendix in his book The Inflationary Universe . It is appealing that the sum of gravitational and thermal energy is the quantity which is balanced . Perhaps that is what your equations do .
Bob,
It isn’t just the movement up or down in relation to the pull of gravity. For gases it is also the extent to which the gas molecules move closer together or further apart under the gravitational influence as they rise or fall relative to the centre of gravity.
That is where the bulk of the mechanical KE to PE or PE to KE exchange comes from.
When you bring that into the equation the temperature of the Venusian surface is fully explainable.
I will be looking at Hockey Schtick’s links when I have time . He provides equations .
But my priorities are my ( approximately ) MidSummer party the first Saturday in August ( anyone along the Front Range is welcome ) and some recursive “stack frame” vocabulary to enhance my 4th.CoSy‘s ability to express such equations and apply them over a sphere .
Bob, see my comment: http://wattsupwiththat.com/2015/07/22/why-we-live-on-earth-and-not-venus/#comment-1992058
Because it is wrong. Work is done on mass by gravity only when it changes height. Gravitational compression can indeed be a source of “heating” — in a gravitationally collapsing protostar, or maybe even in star-wannabe Jupiter. Not so much for the Earth’s atmosphere. The adiabatic lapse rate is what you are trying to describe, and it isn’t maintained by the “work” done by gravity, it is the result of the adiabatic expansion and compression of air that is uplifted or downfalling due to ordinary convection, due to buoyancy. And that in turn is caused by heating or cooling of the gas by something else, not by gravity.
Gravity is not a source of energy for the atmosphere. It is a bank where energy from other sources — almost entirely from the sun, ultimately — can be stored and recovered. But the source of atmospheric heat is pretty much The Sun.
rgb
rgb said:
“Gravity is not a source of energy for the atmosphere. It is a bank where energy from other sources — almost entirely from the sun, ultimately — can be stored and recovered”
Gravity itself is not the ‘bank’ because gravity has no ‘substance’ which can carry such banked energy.
Instead the ‘bank’ is atmospheric mass which, when lifted up within a gravitational field stores what was previously heat in the form of kinetic energy as potential energy which is not heat.
That kinetic energy is then recovered in the subsequent descentt.
The recovered kinetic energy in descent cannot warm the surface directly but instead reduces convection beneath the descending column which allows continuing insolation to heat the surface beneath higher than S-B predicts.
The additional kinetic energy at the surface cannot then be radiated to space because it immediately gets taken up in the next cycle of convective uplift.
The same parcel of kinetic energy at the surface cannot simultaneously be radiated to space AND engaged in maintaining the hydrostatic balance of atmospheric mass suspended off the surface against the force of gravity.
Energy cannot be in two places at once or perform two distinct processes at once.
“That kinetic energy is then recovered in the subsequent descent”
…
Oppps….
…
You forgot something.
…
Whenever some air rises due to heat, there is an equivalent volume of air that has to descend to take it’s place.
Joel,
That is implicit in my account.
Once the first convective overturning cycle completes, a quantity of stored PE is then locked permanently into that cycle and cannot escape to space.
From then on all KE taken up from the surface is matched by KE returning to the surface in a never ending loop and that is why the surface is warmer than S-B. No GHGs needed.
RGB seems to think that the relevant PE is simply the sort of PE stored by lifting a solid or a liquid up against gravity which is a relatively small figure.
Since gases are far more compressible than solids or liquids the PE that they acquire during uplift is mostly derived from the molecules moving apart rather than from the mere uplifting of their mass against gravity.
As the gas molecules move up into a region of lower pressure the moving apart takes up energy in the form of PE and in the process reduces the vibrational activity of each molecule which results in a reduction of KE and thus cooling.
Gases which decrease density always bcome cooler (vibrating less) and gases which increase density always become warmer (vibrating more)
It is the relationship between density and molecular vibrational activity which is most relevant rather than simple height above the surface. This is a special feature of gases which is why we need The Gas Laws.
“a quantity of stored PE is then locked permanently into that cycle and cannot escape to space.”
….
I don’t think that is correct. The effect is a zero sum game. The energy used to move mass up is recovered in the heating due to compression of the downward moving air that replaces the volume in the updraft.
Joel,
It is only a zero sum game after the first convective overturning cycle completes.
At that point just as much energy is taken upwards as is returned downwards in a never ending loop for as long as the atmosphere remains suspended off the surface.
During the first convective cycle the energy taken upward was drawn from radiation leaving to space so from space the Earth would temporarily appear to be at 255K less 33K = 222K.
At the end of that first convective cycle the Earth from space would settle at 255K but you still have that extra 33K (or whatever) sitting at the surface holding the mass of the atmosphere off the surface in hydrostatic balance.
rgb says gravity doesn’t do thermodynamic Work on Earth’s or the Venutian atmosphere (due to adiabatic compression/expansion). Sorry, but this contradicts basic atmospheric physics known at least since Maxwell’s 1872 book Theory of Heat, and which proposed the basis of the barometric formulae, Poisson relation, and the 33C gravito-thermal (not radiative) GHE. Here’s slides from a basic atmospheric physics course that explain Work done by gravity via adiabatic compression/expansion:
http://hockeyschtick.blogspot.com/search?q=adiabatic+work+thermodynamics
See also:
http://hockeyschtick.blogspot.com/2014/11/the-greenhouse-equation-predicts.html
Joel said:
“There is a significant difference between the environment at 1 atm pressure on Venus versus 1 atm pressure on Earth”
Why is that ‘significant’ if temperature and pressure are similar at 1 atm ?
That simple fact shows that it is atmospheric mass and not radiative characteristics which controls temperatures and pressures within planetary atmospheres.
Other features of the surrounding environment are irrelevant.
The only factors that influence surface temperatures are atmospheric mass, the strength of the gravitational field (which controls surface densitry) and the prortion of top of atmosphere insolation absorbed by both surface and atmosphere by conduction and convection.
Any radiative imbalances that develop are dealt with by convective changes that prevent surface temperature changes.
For a detailed explanation as to how that works see here:
http://hockeyschtick.blogspot.co.uk/2015/07/erasing-agw-how-convection-responds-to.html
The second diagram is especially pertinent.
“Why is that ‘significant’??
…
Simple.
…
On earth there is a solid/liquid surface below the 1 atm point. There is no such surface on Venus at that altitude.
…
Inbound radiation behaves differently when it hits the solid/liquid surface at 1 atm on Earth as opposed to the transparent volume beneath the 1atm altitude on Venus.
“Inbound radiation behaves differently when it hits the solid/liquid surface at 1 atm on Earth as opposed to the transparent volume beneath the 1atm altitude on Venus.”
But yet it makes no difference to the relationship between temperature and pressure which rather proves my point 🙂
Convection adjusts to correct for any radiative imbalances.
” But yet it makes no difference to the relationship between temperature and pressure ”
…
The relationship breaks down at the 1 atm level.
…
Any pressure higher than 1 atm makes the comparison between Earth and Venus invalid.
Still confused about the adiabatic lapse rate I see.
Maintained by gravity. An upward moving gas molecule loses speed, and thus temperature, to gravity. A downward moving molecule gains speed and thus temperature.
Correct.
If radiative characteristics serve to introduce a radiative equilibrium then convection changes to negate it:
http://www.public.asu.edu/~hhuang38/mae578_lecture_06.pdf
The proof is that the temperature and pressure within the atmospheres of both Earth and Venus (and other planets) is similar after adjusting for distance from the sun.
Harry Dale Huffman’s calculation is correct and he cannot be discredited on that point just because one might disagree with him on other points.
Harry Dale Huffman’s calculation is incorrect due to a massive problem in his thinking. There is a significant difference between the environment at 1 atm pressure on Venus versus 1 atm pressure on Earth. Below the altitude of 1 atm on Venus there is a lot of atmosphere where radiant energy can dissipate, many km of additional CO2. On Earth below the 1 atm point there is solid surface. You cannot compare the two because it is an “apples to oranges” comparison.
Joel D Jackson: The point is that the *overlapping* portions of the T/P curve are very similar between Earth & Venus, despite huge differences of atmospheric composition. True for all the other planets with thick atmospheres in our solar system as well (Robinson & Catling in Nature). Magellan mission shows T/P curve very close to Earth’s 1976 US Std Atmosphere overlapping portions, & US Std Atm completely excludes CO2 & radiative calculations from their model.
I’ve been aware of it being standard physics since schooldays in the mid 20th century. Only in recent years as it been ignored and replaced with the defective radiative theory of gases.
I think that the importance of the Earth’s magnetic shielding from the solar and cosmic rays radiation is grossly underestimated.
Where did they get the idea that the early earth’s crust was full of transuranics? Being heavier, those elements would have mostly sunk to the core while the earth’s surface was still molten.
This alleged bombardment erosion would have affected all of the inner planets.
The reason why the earth has a thin crust is that a Mars sized planet crashed into the earth some 4 billion years ago. The collision ejected most of the crust which formed the moon.
The two cores combined giving us a larger than average core, combined with a thinner than average crust.
That impact erosion theory is not likely. What distinguishes us from Venus is plate tectonics: we have it but Venus does not. With active plate tectonics radioactive heat is constantly vented by plate boundary volcanism. Absent plate tectonics, heat just piles up beneath the crust. In-plate volcanoes form and excessive heat eventually so weakens the crust that it breaks up into giant slabs. These sink into the interior and an entirely new crust is created. Its atmosphere is a product of these giant volcanic eructations and not a result of an ocean boiling away as some climate scientists like Hansen have hypothesized. On Venus impact craters are not eroded and from crater counts it has been determined that the existing crust is no more than 500 million years old. It is likely that these repaving incidents happen every 300 to 600 million years on Venus. If it is the same age as the earth there may have been as many as eight or ten such episodes in its past.
Venus is not so dissimilar from Earth as it looks on first sight. Just strip Venus atmosphere from CO2, imagine it as storing it to limestone CaCO3… Look what will remain:
16800x10e15 kg of N2 (Earth 4270x10e15kg), 72x10e15kg of SO2, 33.6x10e15 of Argon (Earth 47x10e15), 9.6x10e15kg of water (Earth 1400000x10e15kg), 3.4x10e15 kg of Neon.
Mass of water comparing to Earth seems minuscule, but it is enough to cover whole Venus with 21cm deep ocean.
Let’s assume that Nitrogen/Oxygen ratio will remain same as on Earth 78/21% and some Oxygen remains in atmosphere. It will be 4523x10e15kg (21/78*16800)
Result will be total mass of atmosphere 21432x10e15kg (Earth 5500x10e15kg) with percentual content:
78% N2
21% O2
0.3% SO2
0.1% Ar
0.01% Ne
So we have 4 times more dense atmosphere than on Earth, with almost same composition and some water to run hydrological cycle.
I think only problem of Venus is missing life which did not strip Venus atmosphere of CO2 and stored it as limestone and Carbon.
Sublime.
I don’t completely disagree with this, but I think the much more dense atmosphere also created the surface temperatures that made life capable of stripping out CO2 and reducing it to oxygen and not just limestone but other forms of sequestered carbon comparatively unlikely. I’m guessing its comparative dearth of water made a big difference as well — both because life probably requires free water or even free ice to start up (which in turn requires certain pressure/temperature ranges) and because oceans are enormous thermal sinks. The Earth’s ocean acts like an anti-greenhouse — 4 C on the bottom almost everywhere, warmer in only a very thin layer at the very surface (where even that is warmer). That’s the funny thing. At least 60%, maybe closer to 70%, of the actual surface of the Earth is at or very close to 4 C in temperature. If one averages the temperature over the mass of the fluid components of the Earth’s surface, I suspect that they are collectively much colder than 288 K. Even the land surface rapidly approaches the 10 to 14 C temperature that is supposedly the average once you dig below the surface — ten feet or more down, it is usually cave cool, and remains quite cool until you descend far enough to begin to experience the effect of insulation and switch from surface heating to heat flowing out of the interior as a primary source.
It sounds like Venus is remarkably hot everywhere in its interior, given its surface temperature.
If we had the money and the will, we could certainly do some very interesting things with Venus. The most interesting one would be to try to block sunlight from Venus altogether for a year or two. Try to cool it to where the CO_2 rained out on the surface, chilling it down but good. See if doing this would freeze it deep enough to develop a real crust, one that would last when the screen was removed. Partially remove the screen, let it develop (say) 1 atm of pressure, and see if one could get plants established that would fix the carbon and liberate the oxygen while letting it gradually warm. Drop a few dozen comets on it to bump up the water. Install a huge solar powered laser in orbit that is aimed to blow off its atmosphere (give it escape speed at the top) and run it for a few centuries to see if one can strip it down. Terraform the place!
It isn’t any more of a waste of money than carbon trading, and there is a whole world to reclaim if one can make it work. Mars would be fun to work on as well, but there the difficulty would be getting the raw materials for an atmosphere and (if possible) bumping up its mass so that it would last. One would have to drop whole moons into it and wait a few million years for it to cool down. Venus seems as though it could be a much faster project.
rgb
I find the closeness of the 277+ deep ocean temperature to the 278+ gray body temperature in our orbit an interesting datum .
A strong prima facie indication that Venus’s internal heat dominates is that its surface temperature appears to be nearly uniform over the whole sphere despite its year long day .
Bob,
venus has an effective gb T of only 188K vs 255K for earth. Thats because its bond albedo is 0.90 already. It’s at 3/4 the orbital diameter of earth so the tsi is somewhat more but that albedo has a massive effect. you have some interesting terraforming notions but the biggest buggaboo is that rotation rate. no rotation – no magnetic field. it’s doubtlessly extremely hot inside and capable of one – if it could only spin up. trying to blow off the atmosphere from a big laser – cut idea – assuming it doesn’t launch itself outa orbit by it’s own beam but with no spin – the atmosphere is no mixed well vertically. it’s basically an ocean of co2 at the bottom and nearly 2 (earth) atmospheres of n2 floating on top – so you’d blow away the n2 before you ever made a dent in co2.
seems like pretty much a lost cause – better to colonize the asteroid belt, moon, and mars before wasting effort on venus. even mercury might be effort better spent. besides, in the long run, we need to get further away from that warming sun and when it finally goes, venus is going to be inside.LOL
I’m sorry , but those are such irrelevant BS numbers . Doubly so if “gb” stands for “gray body” .
The gray body ( flat spectrum ) temperature in Venus’s orbit is about 328k .
If you want to discuss any other value , give me a measured full absorption=emission spectrum for the planet and I will tell you its radiative balance temperature .
feel free to go check out the nasa fact sheet on venus. you’ll find its temperature at 184.2k
rgb said:
“It makes it 33 warmer than the greybody temperature, which is not exactly S-B. It isn’t “mass” per se that does it, either — it is atmospheric density, the adiabatic lapse rate, and greenhouse gases all working together that does it. ”
You don’t need greenhouse gases to do it.
Even without GHGs gravity works with mass to produce declining density with height. It is that decline in density with height that allows uneven surface heating (causing density differentials in the horizontal plane at the surface) to result in lighter less dense parcels of air rising above heavier more dense parcels.
Convective overturning inevitably ensues with no need for GHGs. There can be no isothermal atmosphere developing as long as there is uneven surface heating (inevitable around a sphere illuminated by a point source) and a decline in density with height.
Reducing density with height creates the lapse rate slope because work is done against gravity in lifting atmospheric mass and that converts KE at the surface to PE above the surface for a cooling effect.
The process is reversed in descent.
This is basic meteorology which is a specialised discipline from which one can learn that rising columns of air develop huge reserves of potential energy (PE).
Agreed with Stephen, including “you don’t need GHGs to do it,” and that a pure N2/O2 atmosphere would establish a GHE/temperature gradient (even greater than current atmosphere – calculations in my links above).
Maxwell, greatest physicist in history on the topics of heat & radiation said in his 1872 book Theory of Heat that the atmospheric temperature gradient (GHE) is due to dominance of convection over radiative-convective equilibrium, & atmospheric temperatures a function of pressure raised to a ratio of specific heat capacities. Carnot & Clausius also described the essentially the same gravito-thermal GHE.
Basically we are here because we are here, the odds are like drawing 4 of a kind 4 hands in a row, but it happened. With billions of stars it’s likely life started else where as well. I’m mean we have creatures at the bottom of the ocean.
In our solar system having 1 planet with life is incredible, not everyone gets 4 of a kind 4 hands in a row in 5 card stud.
No, it is not wrong. Mathematical derivation of equations which perfectly describe temperature profiles of Earth, Venus, Triton, & all other planets in our solar system with thick atmospheres:
http://hockeyschtick.blogspot.com/2015/07/new-paper-finds-increased-co2-or.html
Same basic atmospheric physics were used to calculate the 1976 US Standard Atmosphere, without one single radiative transfer calculation, and entirely on the basis of mass/gravity/pressure/density. Trace CO2 was completely discarded from their model since it was determined to have negligible effect.
http://hockeyschtick.blogspot.com/search?q=1976+US+Standard+Atmosphere
This illustrates how climate science works, we have three things; what is, what isn’t and what might be. Every statement about greenhouse warming has to be qualified by “than it would have been” and how do we know how hot it would have been. The atmosphere of Venus is mostly carbon dioxide which is a greenhouse gas so why would it not have some effect on temperature as well as atmospheric pressure. If we were to take water out of earths atmosphere then it would seem to me that we would end up with a dessert climate where it was hot during the day but cold at night it would only be uniformly hot if we had the atmospheric pressure of Venus.
A dessert climate?
Must be Baked Alaska!
This article drew lots of excellent comments. Earth is at an orbit where substantial amounts or water are present and temperatures permit all three phases of water to exist simultaneously. This produces a very stable climate regime where the solvent properties of water allow all sorts of chemistry to take place. As for CO2, that was taken care of by the appearance of critters in the ocean that could consume it. And of course more critters appeared to consume the oxygen they produced, namely, us. As for Venus, close to the sun, it has a massive atmosphere which convects just like earth’s so that the high surface pressure along with the shorter orbital radius produces high surface temperatures, too high for liquid water to exist. These simple facts need to be taken into consideration before greenhouse gasses, plate tectonics, and impact erosion are even thought of. In fact, that Venus’ atmosphere follows the same laws of thermodynamics as on earth is powerful evidence that the Climate Consensus and its fixation on radiative models is barking up the wrong tree.
Not quite. CO2 was starting to be removed from the atmosphere long before the emergence of life by liquid water acting as a catalyst to convert CO2 into limestone.
Well said, pochas.
There are many here and elsewhere who are coming to realise that not only are the alarmists wrong in denying the effect of atmospheric mass in causing the so called greenhouse effect but also a number of sceptics are wrong too including the well respected rgbatduke, our esteemed host plus the entertaining and usually informative Willis Eschenbach.
Convection adjusts to counter any radiative imbalances so as to maintain the hydrostatic balance of the atmosphere and no increase in surface temperature ensues unless one changes TOA insolation or global albedo assuming atmospheric mass and the strength of the gravitational field remain the same.
http://www.public.asu.edu/~hhuang38/mae578_lecture_06.pdf
Such was basic high school physics 50 years ago.
An atmosphere will only convect if it is heated from below and only 3% of impinging solar energy reportedly reaches its surface . Thus there would be almost no convection . If there is , it indicates internal heating even if the gravitational-thermal trade-off notion is true .
An atmosphere will convect through its entire depth as a result of density differentials arising in the horizontal plane at any height.
Rising or falling which is initiated at any point in the vertical column forces a chain reaction through the entire column.
This is why my core interest is in constructing the executable notation to succinctly express these relationships and be able to play with them .
You won’t get bottom to top convection in a planar top heated fluid . Venus’s rotation is so slow that there’s not much Coriolis effect . The extreme difference in diurnal insolation would be a driver , but that’s somewhat a different phenomenon .
The is a great deal of food for thought in this discussion , but I have no more time for it now .
I think it is most significant that the science of Venus’s extremes is so unsettled . If we can’t with well winnowed quantitative theory explain Venus’s 225% ratio of surface temperature to gray body temperature , what chance do we have of understanding Earth’s 3% , much less the 0.3% total variation this whole statist useful brouhaha is over .
An atmosphere is never a planar top heated fluid because density declines with height.
Insolation will always penetrate deeply enough through the low density upper layers to set up convective overturning through the entire vertical column.
That is why Venus has convection despite such a small proportion of insolation reaching the surface.
Bob,
Google “images venus” and click “more images.” Convection bands are clearly evident on many images that show the outer atmosphere, even though the atmosphere is heated from the top as you say. Convection occurs when gas heated at the equator advects toward the poles where it cools, densifies, and sinks. Heat of compression raises its temperature as it descends. Finally the hot gas migrates back to the equator to complete the cycle. Actually, the circulation is probably divided into cells as it is on earth.
Mike McMillan said:
“Still confused about the adiabatic lapse rate I see.
Maintained by gravity. An upward moving gas molecule loses speed, and thus temperature, to gravity. A downward moving molecule gains speed and thus temperature.”
That is only part of what happens.
In rising, gas molecules move apart and, as they do so, work is done against the force of gravity which seeks to pull them together into a smaller volume closer to the centre of gravity.
It is the moving apart that creates the bulk of the PE acquired by expanding gases at he expense of KE. That PE is additional to the PE acquired by simple uplift from the surface.
Less dense gases are cooler (vibrating less) and more dense gases are warmer (vibrating more) which is quite unlike solids and liquids, hence the need for The Gas Laws. At all times the gas molecules carry the same total energy but that energy transforms between KE (heat) and PE (not heat) in ascent/expansion and back again in descent/contraction.
Once one understands that concept it all falls into place such that radiative gases are not needed to explain surface temperatures higher then a straightforward S-B calculated radiative only energy exchange would suggest.
Stephen 8:32am: “..radiative gases are not needed..”
Who would you say wrote: “I do subscribe to IR emanating from each level of the atmosphere according to its temperature at that height”? Read the full context and consider that this energy is not destroyed Stephen. Nor does testing show evaporation and convection speed up to counter or compensate for this “emanating” energy. Consider also the water temperature was modulated by modulating the “emanating” energy, shielded and unshielded.
http://www.drroyspencer.com/2015/06/can-infrared-radiation-warm-a-water-body-part-ii/#comment-194491
Energy is not destroyed or created. It is simply transformed to an fro between KE (heat) which does release IR and PE (not heat) which does not release IR.
The proportion of PE relative to KE at any given height determines the amount of IR that will be released because that determines the temperature at that height.
Stephen 10:10am: Good, energy is not destroyed so Stephen gets some of the “emanated” energy entered the water.
Ideally also KE+PE yes, but nature is not ideal, not as tidy in experiments, some KE is transformed to radiation also, to and fro, not just PE. Testing shows no speed up of evaporation and/or convection to counter the “emanating” energy of the cirrus clouds after 1:30am, the water temperature is affected by their added “emanating” energy as this energy is not destroyed.
By the way Stephen, doesn’t it bother you that I can add&subtract PE to your ideal system merely by changing the arbitrary ref. level for PE? Could that be why Venus is so warm at the surface, nature merely changed the ref. level for PE over there? It is closer to the sun, atm. PE must be way down compared to earth in higher orbit.
All this about late heavy bombardments and the formation of the moon from a collision ignores one fact, the oldest rocks on earth, some 4.35 billion years old, show that they were all formed in the presence of liquid water. Would not a bombardment that threw off the crust, or a glancing blow that tore off the moon, also tear off that water and/or those oldest rocks that were formed in the presence of it?
If there was a late heavy bombardment that added the water, it would have to have added that before 4.35 billion years ago.
The idea that a late heavy bombardment is where our water came from came from the exact composition of that water matching one, and only one, comet from the Kuiper belt. However, now we have landed a craft on another comet from way out there, and discovered that its composition does not match that of the other nor of the earths water, this theory is discredited.
Any theory must therefor match the data of these earliest rocks, and the water completely covering the earth at that time, and preserve that water and those rocks through any bombardment or glancing moon causing blow that may happen, or those must have happened before 4.35 billion years ago, leaving an earth that, when it cooled, was completely covered in water.
That Venus is closer to the Sun and has an atmosphere two orders of magnitude more massive than Earth’s seems to be irrelevant in the minds of those seeking attention for this “evolutionary” theory of climate.
1sky1
Yes, it is weird.
I’ve spent the past several years arguing with so called sceptics who think an atmosphere must become isothermal in the absence of GHGs. They think that radiation from those GHGs is what causes the decline in temperature with height which is simply daft. Even Roy Spencer thinks that to be the case.
The decline in density with height occurs because as one moves up and away from the surface of a sphere the space available for the gases to expand into increases exponentially.
By virtue of three dimensional geometry an exponential increase in available space translates into a linear decline in density with height.
As the gas molecules move apart they vibrate less because their kinetic energy is used to power the process of moving apart against the force of gravity which is trying to pull them together into a smaller, lower volume towards the centre of gravity. Reduced vibration manifests itself as cooling and the visible sign of that cooling is the lapse rate slope.
You cannot stop convective overturning when a decline in density with height develops within an atmosphere held off a surface in hydrostatic balance against the force of gravity.
All one then needs is uneven surface heating which is inevitable around a sphere.
It is that convective overturning that pushes gas molecules up and away from the surface in the first place.
Kinetic energy held at the surface and which is engaged in maintaining hydrostatic balance ceases to be available for radiation to space because it is taken up in ascending columns via conduction and convection as fast as it returns in descending columns.
It is locked into the system and cannot radiate out to space past the mass of the atmosphere.
Thus the surface temperature increases as a consequence of atmospheric mass.
Old science that has been forgotten, not taught or deliberately ignored.
Stephen 11:49am: “Thus the surface temperature increases as a consequence of atmospheric mass.”
Because all mass radiates, at all times, all temperatures, all frequencies, depending on its mass extinction coefficient & mass mixing ratio, partial pressure of the particular specie. The water temperature under test was thus affected due radiation from cirrus clouds at 1:30am; evaporation & convection did not have the offsetting effect you claim.
Add more atm. mass, get more radiation as on Venus, less mass, less radiation as on Mars as in:
“I do subscribe to IR emanating from each level of the atmosphere according to its temperature at that height”
Radiation at a surface beneath an atmosphere (beyond that representing the equilibrium state of energy in equalling energy out) is merely a consequence of temperature caused by the interaction between mass and insolation. That temperature is highest where density is greatest because the greater the density the greater the proportion of insolation that is taken up by conduction and convection.
That means the temperature (with its IR) is highest at the surface and declines with height at a rate determined by the decline in density.
The radiative capability of the atmospheric mass is not causing the elevated temperature. The elevated temperature is a consequence of mass conducting and convecting and the IR present at the surface is a consequence of those non radiative processes.
It would all happen even if the radiative capability of the atmosphere were zero.
Diagram 3 in this article is especially pertinent:
http://hockeyschtick.blogspot.co.uk/2015/07/erasing-agw-how-convection-responds-to.html
Stephen 1:10pm: “The radiative capability of the atmospheric mass is not causing the elevated temperature.”
In the real world test, the added IR radiation from the cirrus showing up at 1:30am modulated the water temperature Stephen just as it does the 33K, and even the shield modulated the DW IR. While evaporation and convection undoubtedly had an effect, it was negligible & not immediate, the added IR being at speed of light was immediate. Dr. Spencer constructed a decent cloud detector, as did NOAA ESRL with same confirming results – on the same all mass radiates theory.
“..the IR present at the surface is a consequence of those non radiative processes.”
True but as you repeatedly write their energy exactly balances up and down so they don’t change median T over multiple annual periods yet surface T median does change due a surface atmospheric window (Venus surface has no true windows at wavelengths above 3 microns), and “I do subscribe to IR emanating from each level of the atmosphere according to its temperature at that height”.
“It would all happen even if the radiative capability of the atmosphere were zero.”
In which case so would the sun’s be zero, it would be mighty dark around here, no stars in the sky. If we were here, our campfires would look weird, but we might guess the moon is there based on tides et. al., and a space probe (wired as no radio) running into something.
Trick,
Variations are due to albedo changes altering the proportion of insolation that can be absorbed.
The radiative capability of an atmosphere of pure Nitrogen would be near enough zero as makes no difference for the purpose of my illustration. It does not follow that a sun made of other more radiative materials would also be near enough zero as makes no difference.
You seem to be setting out to obscure the basic point so as to confuse readers and pretend to be of superior intellect.
It is not disputed that all mass radiates to some extent. The point is that radiative capability is not the cause of the greenhouse effect whereas conduction and convection is.
Stephen 2:17pm – I make no assumption on intellect. Only the written word is evident here.
Albedo is reflected SW radiation not convection/conduction or evaporation Stephen, so the IR present at the surface does vary with that radiation modulation in addition to DW IR due clouds. Did the albedo change in Dr. Spencer’s experiment? Did evaporation/conduction change appreciably & immediately? No to both Stephen, the DW IR added from the cirrus changed the water temperature near earth surface measurably/immediately in the same way it affects the 33K. You can see the confirming effects in NOAA ESRL plots.
An easy energy balance including conduction/convection, evaporation & radiation can quickly compute the measured median ~33K and shows 0K on median T from conduction/convection multiple annual averages. So your task is to show a similar eqn. using just mass, insolation, gravity.
Any surface warming beneath stratiform cloud cover is due to a reduction in convection beneath the cloud and not a warming effect from downward radiation.
Additionally, clouds float above higher humidity which suppresses evaporaton from any water surface beneath them so that the water surface warms.
You are constantly introducing irrelevant special circumstances because you do not wish either yourself or readers to understand the reality.
HS has given equations relating to the US Standard Atmosphere which do show that mass, insolation and gravity are all one needs to establish the surface temperature and the lapse rate slope.
It applies on multiple planets with atmospheres with no term required for the radiative characteristics of constituent molecules.
Trick (replying to Stephen)
No, the -33 deg C ONLY works on the flat-earth simplified single-plane equilibrium radiation model favored by Trenberth’s approximations…
The real world (a sphere, last time we saw photo’s of earth) irradiated over an elliptical orbit while rotating every 24 hours at a 23.46 degree angle to the elliptical plane) does NOT come into any sort of -33 degree (not +14 degree, not any other constant temperature) because, in part) the most radiation received is between +45 and -45 degrees latitude, and the most energy radiated is at the regions of the highest temperatures. NO PLACE – even in the vacuum around the moon) exhibits the simplifications you seek.
Now, do that “simplified” radiation model for the actual moon you claim is so easy. Show me the actual full month cycles of the moon’s surface (1/2 meter deep) at each 10 degree band from pole to pole.
Roger 4:06pm: “..33 deg C ONLY works..”
Glad you agree the simplification does work Roger, it is at best a good analog do not stretch it. Stephen has not been able to improve on it with only mass, insolation and gravity.
“..do that “simplified” radiation model for the actual moon..”
Unfortunately the surface of the moon has significance diffraction from the powder, can’t ignore diffraction as was done by Planck, so not even straight Planck radiation is going to work on our moon, it is a toughie; I have seen no simplification that works on the powder. Going to have to grind it out or go set a thermometer field in place equiv. to GCN. Or better.
Actually the simplification gets more complicated on Venus too as the optical depth is so thick multiple layers are necessary not just the one layer that works so well on earth, but there are those that have done it the hard way, get results pretty close to ~730K from 1st principles for surface T and the upward profile after enough iterations.
Stephen – low stratiform clouds form from warm, moist upward convection. At any rate, the ~288K/33K are from global multiple annual periods including all the stratiform nature has to offer. The high ones in Dr. Spencer’s test are not a special circumstance and illustrate real world testing. Any other cloud type would have served the same purpose.
The US Standard 1976 atm. surface 288K was voted on by a committee as well as the profile which averaged mid-tropics testing by the thousands which include the radiation effects, there may be no real natural atm. anywhere showing the same profile, if there is, see the defn. of coincidence. And it has since changed! How could that be if only mass, insolation, gravity are involved?
Stratifirm clouds do not involve convection. They arise from temperature and humidity differences between layers. They are a result of horizontal advection not vertical convection.
Surface warming beneath clouds is a consequence of reduced upward convection (above land) and/or reduced evaporation above water) and NOT downward radiation. It is a non radiative process.
Roy Spencer’s cirrus clouds are at a point along the lapse rate slope where the temperatures are very low and IR coming downward is negligible. Cirrus clouds do not warm surfaces by radiating IR at them.
Roy is a whiz in his speciality but knows little basic meteorology, a common problem these days.
The Standard Atmosphere is a worldwide average and it works to a high degree of accuracy sufficient for aeronautics and rocketry. It may well be that the real world always shows something different at any given location or time but that is because the air is highly mobile and does not detract from the practical and empirical success of the numbers used.
It has not been ‘changed’, merely refined as more measurements accumulate. It is getting ever closer to the actual thermal profile derived from equations involving only mass, gravity and insolation. Radiation not needed.
Stephen 1:09am: “Cirrus clouds do not warm surfaces by radiating IR at them.”
Dr. Spencer’s test results show real world nature does not agree with your assertion. NOAA ESRL confirms Dr. Spencer’s results with daily records at its observing stations, detecting passing clouds with same results. To get meteorology right, according to test & instrumental observation, Stephen, you will have to add effects of radiation to your repertoire.
1:15am: “The Standard Atmosphere is a worldwide average…it has not been changed.”
Not worldwide only around mid-tropics, and US Standard Atm. was changed, updated by committee vote in 1993 to include the avg. changes nature made in the interim. It is not “derived” from eqn.s involving only mass, insolation and gravity, the numbers are from averaging huge amount of test flights in and around the mid-tropics including all of nature’s radiation therein.
Trick claims 1976 US Std Atmosphere “is not “derived” from eqn.s involving only mass, insolation and gravity, the numbers are from averaging huge amount of test flights in and around the mid-tropics including all of nature’s radiation therein.”
False, the 1976 US Std Atmosphere IS derived from basic physical chemistry & physics of molecular mass/gravity/pressure/density. The complete mathematical derivation & mathematical model is described in 50 pages of the 1976 US Std Atm technical description here:
http://hockeyschtick.blogspot.com/2014/12/why-us-standard-atmosphere-model.html
And their model does not use one single radiative transfer calculation whatsoever. AFTER developing the mathematical model, the model was then verified with millions of rocket, radiosonde, & flight observations.
Hockey , you and Stephen have opened my eyes to the very profound relationship between temperature and gravity . Alan Guth’s ( not original with him ) notion of gravity as being negative energy simplifies the thinking for me . So what is balanced at the effective radiative surface is
gravity + KineticEnergyand that is the quantity the divergence theorem holds constant .I’ve said since first getting diverted into this slough that calculating the mean temperature of a planet was more akin to calculating the temperature of a volume of gas thru gas laws rather than getting involved with the details of the internal eddies . Whatever convection there may or may not be doesn’t even enter into this constraint .
I’m glad all I did in my Heartland talk is show the quantitative absurdity of Hansen’s claim that Venus’s surface temperature was due to its spectrum rather than claim I knew the cause . I look forward to implementing and confirming your computations . I had been aiming at mapping the cosine function over the hemisphere and adding simple thermal conductance and radius as the next couple of expressions to implement ( in 4th.CoSy ) , but this is simply scalar and clearly the most important additional parameter .
BTW : my annual CoSy MidSummer Mountain Mela is next Saturday , August 1 . I invite anyone along the Front Range interested in this stuff enough to be reading this — and I know we are overrepresented here .
Damn , missed a closing .
A closing “” . Did that do it ?
( What ever value there is in having posts be archival is not a justification for no ability to preview or modify at least for a short period . )
Oops, corrected tag.
HS 11:43am: The US Standard Atmosphere, in the foreword, communicates and I quote verbatim skipping some uninformative classification detail: “The definition of the lowest 50km was recommended as the standard for international adoption by the International Standards Organization (ISO) cognizant committee…..It was approved by the ISO Member Bodies in September 1973 as the ISO Standard Atmosphere (ISO 1973).”
The 1976 starting z=0.0m temperature 288.156K is based on two international agreements (15C from 1924 !! & unchanged from that date) & profile avg. 6.5K/km is the product of a committee recommendation & approval, not nature, the Standard Atm. is “a hypothetical vertical distribution of atmospheric temperature, pressure and density…roughly representative of year round midlatitude conditions.”
Though the committee was guided by the tests and the science, it is not a natural atm. that can be studied for climate research or to draw reliable climactic conclusions, since it is hypothetical, thus you & Stephen should use actual soundings and basic/advanced science from measurement, analysis and test data which are intended for climate related conclusions. Commonly available in relative modern text books, especially those devoted to radiation (and RTM!).
The ISO standard typical uses: “pressure altimeter calibration, aircraft performance calculations, aircraft and rocket design, ballistic tables, and meteorological diagrams. The air is assumed to obey the perfect gas law and hydrostatic equation…”
Noticeably absent is an intended usage to draw real world (non-ideal) climate related conclusions.
As a hypothetical, the US Standard Atmosphere is derived from ideal non-real world eqn.s and “is not “derived” from eqn.s involving only mass, insolation and gravity, the numbers are from averaging huge amount of test flights in and around the mid-tropics including all of nature’s radiation therein.”
For instance, beyond mass, gravity, and insolation there are “diffusion coefficients”, molecular weights, number density of individual species, Maxwellian velocity distributions discussed and many more considerations. It is a good read. You can learn a lot. The various eqn.s for Tm came from expressions in the ARDC Model Atmosphere 1956 (Minzner and Ripley), as revised, from rocket and satellite data, a good read, See Fig. 2 for the curve fit. This when Venus data was a decade away.
“..their model does not use one single radiative transfer calculation.”
Agreed, ISO standard is not of RTM real world accuracy (meaning RTM used for analyzing real earth profiles close to observed as can be done for Venus), ISO Standard is only ideal & hypothetical committee vote after curve fitting.
“I’ve spent the past several years arguing with so called sceptics who think an atmosphere must become isothermal in the absence of GHGs. They think that radiation from those GHGs is what causes the decline in temperature with height which is simply daft. Even Roy Spencer thinks that to be the case.”
Yup, me too.
Easiest math proof that a pure N2 atmosphere would have an even greater GHE/tropospheric temperature gradient than the current Earth atmosphere:
http://hockeyschtick.blogspot.com/search?q=N2+Boltzmann+distribution
The decline in density with height occurs because as one moves up and away from the surface of a sphere the space available for the gases to expand into increases exponentially.
Shouldn’t that be quadratically?
As the gas molecules move apart they vibrate less because their kinetic energy is used to power the process of moving apart against the force of gravity which is trying to pull them together into a smaller, lower volume towards the centre of gravity. Reduced vibration manifests itself as cooling and the visible sign of that cooling is the lapse rate slope.
The translational kinetic energy is what is used to move them apart, not the vibrational energy. If the molecule is vibrationally excited and possesses a dipole then it will lose the excess vibrational energy by radiation.
Phil,
I’ll check both points but if you are right and my terminology is not correct the conclusions are the same.
There is a linear decline in temperature with height whether the decline in density is quadratic or exponential.
Molecules cool and move about less as they move apart whether it is a loss of translational or vibrational energy. Can vibrational energy decline by means other than loss of a photon such as by conduction to another molecule that has lost translational energy ?
If so, the distinction is not relevant.
HS 11:43am: The US Standard Atmosphere, in the foreword, communicates and I quote verbatim skipping some uninformative classification detail: “The definition of the lowest 50km was recommended as the standard for international adoption by the International Standards Organization (ISO) cognizant committee…..It was approved by the ISO Member Bodies in September 1973 as the ISO Standard Atmosphere (ISO 1973).”
The 1976 starting z=0.0m temperature 288.156K is based on two international agreements (15C from 1924 !! & unchanged from that date) & troposphere profile avg. 6.5K/km is the product of a committee recommendation & approval, not nature, the Standard Atm. is “a hypothetical vertical distribution of atmospheric temperature, pressure and density…roughly representative of year round midlatitude conditions.”
Though the committee was guided by the tests and the science, it is not a natural atm. that can be studied for climate research or to draw reliable climactic conclusions, since it is hypothetical, thus you & Stephen should use actual soundings and basic/advanced science from measurement, analysis and test data which are intended for climate related conclusions. Commonly available in related modern text books, especially those devoted to radiation (and RTM!).
The ISO standard typical uses: “pressure altimeter calibration, aircraft performance calculations, aircraft and rocket design, ballistic tables, and meteorological diagrams. The air is assumed to obey the perfect gas law and hydrostatic equation…”
Noticeably absent is an intended usage to draw real world (non-ideal) climate related conclusions.
As a hypothetical, the US Standard Atmosphere is derived from ideal non-real world eqn.s and “is not “derived” from eqn.s involving only mass, insolation and gravity, the numbers are from averaging huge amount of test flights in and around the mid-tropics including all of nature’s radiation therein.”
For instance, beyond mass, gravity, and insolation there are “diffusion coefficients”, molecular weights, number density of individual species, Maxwellian velocity distributions discussed and many more considerations. It is a good read. You can learn a lot. The various eqn.s for Tm came from expressions in the ARDC Model Atmosphere 1956 (Minzner and Ripley), as revised, from rocket and satellite data, a good read, See Fig. 2 for the curve fit. This when Venus data was a decade away.
“..their model does not use one single radiative transfer calculation.”
Agreed, ISO standard is not of RTM real world accuracy (meaning RTM used for analyzing real non-hypothetical earth T(z) profiles close to observed as can be done for Venus), ISO Standard is only ideal & hypothetical committee vote after some ideal eqn.s and curve fitting.
Nonsense.
Well now, Since New Horizons finally reconnected me WI-FI with Yuggoth, that’s PLUTO to you denizen’s of Erf, we can answer your ape like grunts with the wisdom of the Fungi from Yuggoth.
The Reasons you are not citizens of Venus, is because the Elder Things settled on Erf, and grew your ancient ancestors in a vat, in that frozen waste you call the Antarctic.
Simples.
By the way, it was a bloody nuisance playing hide and seek with that probe, spent ages looking from an empty hidy hole, Pluto isn’t exactly large you know.
Your Over lord superiors have spoken,…wait which button do I push?,…that one?, no? that one!,…well that’s daft who puts a self destruct button next to an off switch,…
Bear in mind the gods don’t really care what we believe. But we do keep them smiling. 🙂
This has been an interesting thread.
For any lurkers like myself a few pics of the surface of Venus may be interesting:
http://cseligman.com/text/planets/venus.htm
wayne,
Consider a rocky planet with no atmsphere. Then volcanic activity releases a bubble of gas.
That gas will expand without pushing against other gas molecules.
According to your scenario it will not cool during expansion because there are no other gas molecules for it to push against.
In reality it will expand againsty the pull of gravity which constantly tries to draw the gases back towards the centrre of gravity.
Work is done against gravity and the gases cool during expansion as per The Gas Laws.
Will.
You contend that air suspended off the ground against gravity in hydrostatic balance has no weight.
How, then, do you account for pressure at the surface which falls when the surface is overlain by warmer lighter rising air and rises when the surface is overlain by colder denser falling air?
Stephen Wilde says, July 26, 2015 at 3:23 am:
“Consider a rocky planet with no atmsphere. Then volcanic activity releases a bubble of gas.
That gas will expand without pushing against other gas molecules.
According to your scenario it will not cool during expansion because there are no other gas molecules for it to push against.”
Stephen, this is not “according to [wayne’s] scenario” (is he even on this thread?). It’s according to science, meteorology, atmospheric physics, common knowledge among people who’ve taken even a single course on thermodynamics.
Of course the gas won’t cool during expansion when it has nothing to push against. It’s called “free (or isothermal) expansion” and happens without a change in T. Just look it up. The opposite is “adiabatic expansion”, where the air rising is constrained by surrounding air and thus have to push it to the side (against a certain external pressure) in order to expand, thus DOING WORK ON THE SURROUNDING AIR, losing internal energy in the process, thus cooling. You can read about it for instance here (or in ANY learned text on the subject; if you want more sources, I’ll be happy to provide some, or you can just google “adiabatic process”):
http://eesc.columbia.edu/courses/ees/climate/lectures/atm_phys.html
From the link (under the heading “The first law of thermodynamics and adiabatic expansion:”):
“In reality it will expand againsty the pull of gravity (…)”
What does this even mean? Expand against the pull of gravity!? The bubble of gas will expand in all directions, Stephen. Up, down and to the sides. Spontaneously. Because there’s nothing stopping it from doing so. The gas will simply dissipate until it’s no longer a gas, simply according to the various trajectories of the individual gas molecules, the molecules eventually drawn back to the surface by gravity, if, before this happens, they don’t manage to escape into space. This is how the exosphere is maintained on different moons and asteroids in the solar system. An exoshpere is not really an atmosphere in its proper sense, because the gas molecules are spread so far apart that they hardly, if at all, interact.
Aaarrgh! Thanks, wordpress!
Kristian,
I meant to post on another thread elsewhere but no matter since you make the same error as the said wayne.
The example of isothermal expansion is limited to a parcel of gas which expands equally in all directions without altering its height. That assumes no solid surface beneath it restricting downward expansion.
A bubble of warm gas exiting from the ground and rising upwards against gravity whilst expanding as it does so is a very different scenario.
The gas leaving the ground will expand and cool as its molecules move upward and apart even without any surrounding molecules for it to do work against. There is no container wall for it to do work against.
In that case ‘the surroundings’ are the ambient gravitational field which is seeking to pull the gases back down towards the surface.
The quote you found is not applicable to the latter scenario and it is the latter scenario that applies to atmospheres around planets as opposed to free floating parcels that do not change height.
Stephen, you say:
“The gas leaving the ground will expand and cool as its molecules move upward and apart even without any surrounding molecules for it to do work against. There is no container wall for it to do work against.”
No, Stephen. It doesn’t magically come true just because you say it’s so, just because that’s how you picture it.
All you do is make up your own physical principles as you go along and state them as truth. You’re getting nowhere with such an approach. You will convince some people who don’t know this subject. The people who do know it, however, will laugh, shake their heads or just ignore. I’m trying to make you open your eyes and step out of your bubble. You need to pick up a book soon and start reading. You can never expect to be taken seriously before you do and stop promoting your self-invented nonsense physics. What you say goes squarely against the entire fields of thermodynamics, meteorology and atmospheric physics. You have to just realise that. Wake up.
Free, isothermal expansion of a gas happens in a vacuum. Gravity or no gravity. Gravity doesn’t cool the gas. If there’s no surrounding air for the gas to do work on, it will not cool. Everyone who has read just a little bit about these topics knows this. And that’s why we don’t know what to do with you. Because you simply won’t take that step back and go ‘Hmmm, maybe I should pick up that book’, no matter how many times we tell you (and show you) how fundamentally wrong you are. We lead you to the water. It’s there, right in front of you. Just drink. (It’s there. In black and white.) But you won’t. You just go ‘Oooh, look over there!’ And you’re off, as if nothing had happened. And everything starts all over again … It’s an impressive ability that you share with Doug.
You say: “The quote you found is not applicable to the latter scenario and it is the latter scenario that applies to atmospheres around planets as opposed to free floating parcels that do not change height.”
!!!!! The quote I found SPECIFICALLY addresses what happens in the atmosphere, Stephen. And I’ve shown you tens of similar ones before. They all say the same thing. It’s everywhere. It’s one of the first things you learn in this field. The fundamental connection between the 1st Law of Thermodynamics and the adiabatic process is legendary. This knowledge, these principles, go back to the days of Carnot and Clausius and their heat engines. It is work against surroundings, against external pressure, Stephen. NOT GRAVITY!!!!
Q = 0, so ΔU = -W. Pressure/volume work, Stephen. Ideal gas law. 1st Law of Thermodynamics. Adiabatic process. Look it up …!
Your obstinate refusal to acknowledge these simple (and totally uncontroversial) physical concepts, rather insisting that everyone else is simply wrong and misguided and only you (and Doug) are right, we all somehow missed it, and only you see it, frankly speaks volumes all by itself.
But it’s sad to behold.
I don’t see what this raging quibble is over . I doubt if Stephen has any real disagreement about gas laws sans the gravity parameter .
Stephen’s point , and Hockey’s and , I think Huffman’s is that gravitational energy ( or negative energy ) must be considered in temperature balance equations . I just never thought of it as having a significant static effect . But it’s effect is clearly rather simply and precisely computable .
Odd as it seems to me , the pressure and temperature lower in a gravitational field must be greater to balance a radiant temperature in essentially a 0 gravitational field .
Bob,
This “raging quibble” is over the adiabatic process and how it works in our atmosphere. Stephen thinks he’s come up with something that no one else in thermodynamics (all the way from Carnot and Clausius), in meteorology or in atmospheric physics, has ever realised, that adiabatic cooling and heating really works simply by a conversion back and forth between molecular KE and (what is perceived as) molecular PE as the air rises and falls in the atmospheric column. This is of course nonsense. And it is common knowledge in these fields that it is.
Stephen is simply mixing up the mechanical movement of bulk air up and down within the tropospheric column (where there is conversion going on between KE and PE, only bulk (centre of mass) KE and PE, not affecting the air temperature at all) with the adiabatic process, which only involves the expansion and contraction of the air as it moves up and down and thus faces a reduced, then increased, external air pressure. The adiabatic process affects directly the temperature of the air, because it pertains to its internal (microscopic/molecular, disordered) energy.
This is elementary stuff, and it annoys people who know these things, who have studied them thoroughly at university level for years, constantly having to wade through Stephen Wilde’s misguided ramblings on these issues that he clearly knows nothing about, just wild (!), self-invented physics that he does his best to push at every opportunity on whoever might pass by.
Bob, you say: “Stephen’s point , and Hockey’s and , I think Huffman’s is that gravitational energy ( or negative energy ) must be considered in temperature balance equations . I just never thought of it as having a significant static effect . But it’s effect is clearly rather simply and precisely computable .”
Hockeyschtick and Huffman are both wrong. They don’t see the forest for the trees. Gravity works together with the mass of an atmosphere to create a pressure and a density gradient, fine. However, these two parallel gradients can both be compressed and stretched, and the surface starting point of the density gradient can likewise be moved back and forth along the x-axis. How? Through a change in temperature, creating a change in ‘internal (or thermal) pressure’. This will not affect the adiabatic lapse rate, but it will affect the altitude of the so-called ‘average atmospheric level of upward radiation’, better known as the ERL. Same with mass and/or gravity. Increase the atmospheric mass (or planetary gravity) and the ERL is forced upward, away from the surface. This in turn will cause a rise in surface temperature.
HS claims that the ERL is simply located at the atmospheric ‘centre of mass’. It’s not. On Earth (and Titan) it’s close. Not quite there, but in the general ballpark. That’s because these two bodies happen to have ‘moderately’ thick atmospheres, and thus their ERL is forced somewhat off the surface. On Mars, the atmosphere is extremely thin and light, so thin that the ERL is actually to be found on the surface, below the entire mass of the atmosphere. At the other end of the spectrum, Venus’s atmosphere is extremely massive (heavy and dense), which means the ERL is forced 60-65 km off the ground, to the actual tropopause cloud layer, above most of the atmospheric mass.
Kristian said:
“Free, isothermal expansion of a gas happens in a vacuum. Gravity or no gravity. Gravity doesn’t cool the gas. If there’s no surrounding air for the gas to do work on, it will not cool.”
Movement away from a centre of gravity by way of raising height above a body of mass large enough to generate a gravitational field allows expansion that results in cooling as per The Gas Laws.
Expansion without movement away from a centre of gravity does not.
My example does state that the bubble of gas emanating from the rocky surface is warmer than the temperature of the surrounding vacuum otherwise it would not rise.
“It is work against surroundings, against external pressure, Stephen. NOT GRAVITY!!!!”
There is no external pressure when there is no gravitational field. Gravity imparts weight and thus pressure to mass. Expansion without changing position relative to a centre of gravity involves no change in external pressure and thus no change in temperature.
Kristian is so emotionally committed to the false impression that cooling in uplift is caused by rising air passing heat energy to surrounding moecules by doing work on them that he cannot accept that the work being done in adiabatic uplift is being done against the gravitational field and not against the surrounding molecules.
Even in the quote he refers to the reduction in outside pressure comes before the expansion and the walls of the parcel are therefore moving outward at the same rate as the molecules in the parcel so that the walls are exerting zero resistance against the outward moving molecules.
Zero resistance from the expanding walls means trhat no work is being done on those walls. The work being done is being done against the gravitational field which has been weakened so as to reduce the external pressure in the first place.
I am expressing the established science on this point. Kristian’s idea that a bubble of warm gas rising off the surface of a planet that previously had no atmosphere will not cool as it expands is bizarre and clearly contrary to The Gas Laws.
Kristian’s quote says:
“When a force is moving an object over a given distance it does work. Thus the expanding air parcel does work on its surroundings. ”
That does not say that the surroundings are the surrounding molecules. The surroundings against which work is being done is the ambient gravitational field when the expansion follows an initial reduction in external pressure. It is the movement across a distance that matters whether there are other molecules in the way or not. If there were no initial reduction in external pressure prior to the expansion then in that case the work would indeed have to be done against surroiunding molecules but that would then be a diabatic process with heat moving out from the parcel to those surrounding molecules via the work done.
If there is no gravitational field or if the expansion all occurs with no change in height then there is no change in temperature despite the expansion because then no work is done against either the ambient gravitational field or against surrounding molecules.
For expansion with no change in height within a gravitational field the work done against gravity in the upward expansion is exactly matched by the expansion with gravity in the downward expansion for zero net work overall hence no change in temperature.
Also, for expansion with no change in height there will be no movement of kinetic energy in or out of the parcel by way of work done on surrounding molecules because all the molecules involved both inside and outside the parcel average out to the same temperature and pressure.
So I think Kristian has it wrong about the established science rather than me.
Stephen Wilde, July 26, 2015 at 7:24 pm:
“So I think Kristian has it wrong about the established science rather than me.”
Sorry, Stephen. This is not a matter of opinion. The adiabatic process works by the air expanding against a reduced external air pressure, thus doing work on the air surrounding it, thus losing internal energy, thus cooling; conversely it works by the air contracting against an increased external air pressure, thus having work done on it by the air surrounding it, thus gaining internal energy, thus warming.
Q = 0, so ΔU = -W. 1st Law for the adiabatic process. Look it up.
When you release carbon dioxide from a fire extinguisher, it quickly expands, cools and condenses as a result. It does so whether you shoot it downwards or upwards or just straight ahead. Meaning, gravity doesn’t matter here. Only the swift expansion against a lowered external pressure does. Same with a cylinder piston. The air warms as the piston quickly compresses it and cools as it falls back, letting it expand again. This happens to the same extent whether the piston is working in an upward or in a downward or in a horizontal direction. Gravity takes no part. This is the adiabatic process, and it works by the exact same physical principles in the atmosphere as it does in these two examples, only there the air volume in question will have to move vertically for the external pressure to change.
This is just how it is. It doesn’t matter what you “think”, Stephen. This is how the adiabatic process works. Period. Gravity takes no part in it. That’s just your delusion.
I’m not happy with paras 3 4 and 5 above so please ignore. Para 1 is OK.
You can’t have expansion with no change in height within a gravitational field because the added thermal energy that needs to be supplied diabatically in order to cause the expansion creates a density change that inevitably leads to adiabatic uplift.
“Stephen. This is how the adiabatic process works. Period. Gravity takes no part in it”
Obviously wrong:
http://www.britannica.com/science/lapse-rate
“The dry adiabatic lapse rate for air depends only on the specific heat capacity of air at constant pressure and the acceleration due to gravity”
That’s the lapse rate, Stephen. Not the adiabatic process.
Sigh
The adiabatic lapse rate is a product of the adiabatic process.
Work done against gravity is integral to it and NOT work done against surrounding molecules. The latter is a diabatic process because heat moves in or out which is not permitted for an adiabatic process.
The former does not move heat in or out. The heat energy is transformed to or from PE instead.
Stephen, you say: “Work done against gravity is integral to it and NOT work done against surrounding molecules. The latter is a diabatic process because heat moves in or out which is not permitted for an adiabatic process.”
You don’t know ANYTHING about these things, do you? You haven’t read ANYTHING about even basic thermodynamics. And still you comment on this issue as if you words alone were enough to verify your nonsensical claims about reality. Unfathomable.
First you need to familiarise yourself with the 1st Law of Thermodynamics, what it is and what it says.
Then you need to know how ‘heat’ [Q], ‘work’ [W] and ‘internal energy’ [U] is defined in thermodynamics. They are both terms in the mathematically expressed version of the 1st Law.
Further, you will have to read about the basic definition of an “adiabatic process”. How is it expressed mathematically? And how does it connect with the 1st Law?
During this learning process you will encounter the term “PV work”, pressure volume work. PV work is the kind of thermodynamic work that operates in an adiabatic process. You can read about it here:
https://en.wikipedia.org/wiki/Work_(thermodynamics)#Pressure-volume_work
The work done by the system in an adiabatic process is PV work, thus it involves the internal and external pressures of the system, where the system expands against the external one (the surrounding pressure), thus doing (PV) work ON the surroundings. It’s there in black and white, Stephen. Once again. Like I said, this is not a matter of opinion. This is not about what you think. It’s about what the physics says.
There is much more to learn even after this, but start with this. It should occupy you for a while.
Kristian,
When expansion occurs during uplift the movement is towards an area of lower pressure.
No work needs to be done against surrounding molecules in that situation.
The rising parcel simply expands into the space made available by the less dense, lower pressure, medium,.
The only work that is necessary is work against the downward force of gravity and the equations work perfectly well in that scenario.
Convective overturning is not like a rising parcel pushing static gases above it out of the way and thus doing work against them in order to ‘win’ additional space for expansion.
Once the first convective overturning cycle completes, the entire cycle is in constant motion upwards in one column and downwards in the adjacent column.
Thus as fast as a rising parcel expands into the lower pressure space above it the molecules in that higher space are themselves moving out of the way by rising even further up and reducing their own density. No work is needed between rising molecules and the molecules above them.
Let’s try and get to the nub of the disagreement about the adiabatic process between me on the one hand and Kristian on the other.
As I recall, Kristian accepts that, for a process to be adiabatic, heat cannot transfer in or out AS HEAT.
I agree with that.
Kristian then said that heat can be transferred in or out AS WORK without the process ceasing to be adiabatic. Thus, rising molecules can do work on surrounding molecules so that heat transfers, from the rising parcel which cools, to the surrounding molecules which warm.
I disagree with that.
Is that a fair summary of the point in dispute ?
If so, then I will proceed to explain why I disagree with the second part but there is no point in doing so unless I have correctly identified the issue.
Stephen 5:08am – I will try to help, again, since you can’t read math. Lapse means a decline of something over a distance.
Neither of you are being mathematically precise. For the derivation of the dry adiabatic lapse rate in the 1890s, -g/Cp ~ 9.8K/km for earth, for the math to be simplified & proceed, which you can’t just imagine, Poisson assumed the expansion process (by reading thru his derivation not wiki, not a link on the net, but his original work) takes place:
1. at the same temperature as the surroundings T=Ts, and
2. at same pressure as the hydrostatic surroundings P=Ps. These two allowed him simpler integration over the z height.
And 3. no condensation, not moist, so dry.
Condition 2. means no work was assumed to be done on or by the air in the expansion process to derive the DALR. The cooling T comes from only gas expansion with z increasing due to surrounding pressure, density decreasing:
P(z)=density(z)*R*T(z).
So if P down, density down, then T down in the expansion process.
Poisson then went on to relax the condition on T equal to surroundings (keeping 2. and 3.) and found a more precise ideal troposphere lapse derived with integration that was more time consuming effort, you can see all this in his math if you could read it:
T(p) = To * (P(z)/Po)^R/Cp
None of this really happens in the troposphere as this work is ideal, that is why the ELR is the natural lapse existing in nature, needing RTM analysis or thermometer on a rocket/balloon to know at a given location with increasing z. The Stnd. Atm. curve fit existing midlatitude soundings and drew a straight line through them at exactly 6.5K/km guided by idealism. Closer to hub?
In the standard committee voted 6.5K/km, T is not equal Ts, P not equal Ps, and there are sometimes on avg. clouds, i.e moist not dry. Interestingly, this can be solved rigorously mathematically too but too advanced for your limited math skills to even attempt to discuss.
NB: I did not use “adiabatic” term in discussion except in DALR, did not use “heat” term, these are imprecise. Cause confusion.
Trick,
You have completely missed the point at issue.
Actually, Trick, this bit is useful:
“Condition 2. means no work was assumed to be done on or by the air in the expansion process to derive the DALR. The cooling T comes from only gas expansion with z increasing due to surrounding pressure, density decreasing:”
Kristian’s proposal seems to be in breach of that condition 2. Since gravity creates the decline in surrounding pressure and density one could argue that work is being done against gravity, just not against surrounding air molecules.
Stephen – A swing and miss then a hit for assumption 2. in 1st sentence at 8:54am. Pressure P=Ps does mean Poisson assumed no work done.
“..one could argue that work is being done against gravity..”
What did I just write? No, Poisson’s math moved forward with no work at all being done in the process of the gas expansion, P=Ps. g entered into the mix from the hydrostatic equilibrium of the atm. in that surroundings pressure gradient = -density of surroundings * g. Then P=Ps was key assumption.
It is ok to think of the air rising and doing work against gravity separately Stephen but you continuously miss the pv term in that discussion so it goes nowhere & sets Kristian off as at 9:34am. The specific enthalpy of a parcel decreases as it rises Stephen, not just the molecule KE, as I’ve repeatedly & futilely noted for you. For that you DO need the pv term to account for the work done by the parcel on/from its surroundings as in Kristian’s 9:34am.
I have noted you have recently written of the forces between molecules which is progress, THAT is where the important pv term arises in test and it is part of the conserved quantity “dry static energy” in the process of adiabatic ascent or descent but you have resisted this notion, focusing incorrectly on just PE+KE.
It may be useful to note that Poisson did not even need to consider the parcel in motion, he just used the mathematical process it would undergo from T=Ts and P=Ps & dry. He simply differentiated over z height one of his relations from the ideal gas law connecting p,V,T and made the assumptions I noted along the way. I would lay the calculations out but it would be futile.
Trick,
You are raising straw men from what I say.
I have it right as confirmed here:
http://virakkraft.com/Experimenting%20on%20a%20Small%20Planet.pdf
Kristian is wrong.
Work is done against or with gravity when the volume changes and not against surrounding molecules.
Stephen – No strawmen. That short paragraph article doesn’t have much if any foundation. You can do a lot better. “Cools by expansion” is sort of mixed with rising and descending work. Two different math concepts are simply mixed up.
Kristian is right about the pv term for ascending and descending work being done by surroundings, intermolecular forces and from gravity in ELR; Poisson is right about the “cooled by expansion” when no work is done DALR. Again, cooled by expansion is DALR no work, but when work is done you have the ELR. That paragraph confuses & mixes the two. You could easily see this if you could read the math involved, but alas you cannot. It is futile to convince you otherwise as I noted. Keep searching for a link that gets it not so confused, you know like a good text book, make it not futile.
It is the gravity field which comprises the relevant ‘suroundings’ against which work is done when a gas volume changes due to uplift and descent and not the surrounding molecules.
Kristian is wrong but neither he nor you will ever admit it.
Stephen – Again, the gravity field g only enters the DALR derivation as I wrote through hydrostatic equilibrium of the atm. in that surroundings pressure gradient = -density of surroundings * g. Then assuming Ps=P of the subject air. There is no motion against g.
For the DALR derivation is from simply taking the derivative dT/dz of the 1823 Poisson relation drawn from IGL, hence there is no motion against gravity at all in the DALR as work=0. The gas cooling is 100% from its expansion. In 1888, Helmholtz extended the work (with tougher integration of differential T not constant due advancement in calculus) to the formula I gave earlier and it became commonly known in meteorology as potential temperature in the 1890s.
Motion against gravity comes in the reduced ELR, work not equal 0, upon parcel ascent and descent against/for gravity which also brings in the pv term that Kristian discusses and you have never accepted, unfortunately, p*v energy is hard to imagine but you are getting there discussing intermolecular forces acting over a distance. Feynman: molecules close in repel, when they get far away molecules attract.
The motion against g occurred when the gases first rose off the surface. That was when the DALR was first put in place.
This is what is wrong with Kristian’s account:
Let’s look at Kristian’s use of equations.
He uses W (work), Q (heat) and U (internal energy).
For the starting point we can set all three at 0 because we are interested only in changes and not absolute values.
Kristian says that work can take place against surrounding molecules (say 1 unit of work) which reduces internal energy (by say 1 unit) but that Q can nonetheless remain at 0.
That contradicts his assertion that a reduction in internal energy results in cooling. In fact, reducing U by 1 unit must also reduce Q by 1 unit if the units of internal energy are kinetic energy rather than potential energy.
So how has he become so confused?
Kristian said:
“if there is cooling of the system, meaning, a reduction in system U, it can only be caused by a transfer of energy out of the system in the form of ‘work’ [W].”
However, work is NOT a ‘form’ of energy. Work is a process whereby energy can either be transformed (say KE to PE or back again) or moved (inside or outside of the initial volume).
Since he is wrongly asserting that work is a form of energy he thinks that 1 unit of work (+1) can offset a reduction of internal energy (-1) to leave Q on the other side of the equation at 0. He thinks that the unit of W is a form of energy that can be added back to the reduced internal energy to leave Q unchanged.
In fact what happens is that 1 unit of W will either transform 1 unit of U from KE to PE which reduces both U (if internal energy is defined as kinetic energy) and Q by 1 unit
OR
1 unit of work will move 1 unit of U out of the parcel which also reduces the Q of the parcel by 1 and in order to conserve energy the air outside of the parcel must gain 1 unit of internal energy and 1 unit of Q. Just as before, the initial parcel shows a reduction of 1 unit in both U and Q.
The former involves work against gravity (adiabatic since no internal energy is lost or gained by the parcel, simply a transformation from KE to PE) and the latter involves work against surrounding molecules (diabatic because some of the internal energy has moved out to the surroundings).
The temperature change in the real world is overwhelmingly the result of the adiabatic process arising from work done against gravity.
Stephen – “The temperature change in the real world is overwhelmingly the result of the adiabatic process arising from work done against gravity.”
No sir, the DALR is ideal not the real world Stephen, its cooling results 100% from expansion, not from work done against gravity, you can imagine for each molecule rising, one falls in the expansion process undergone by the gas of interest. The ELR is real world where the rising and descending parcels conserve the “dry static energy” not just KE+PE since there are forces between the molecules compressing & expanding which is also conserved (can’t destroy or create that existing energy either).
“..work is NOT a ‘form’ of energy..”
Has no meaning I can see, work is energy, a force over a distance of which there is none (W=0.0) in the derivation of the DALR arrived at in the 1800s, work was set = 0.0 in that original derivation taking dT/dz of an ideal gas under hydrostatic conditions & the 3 conditions I noted.
Recommend reading David Deutsch on chemical scum living on a typical rock in a typical etc etc
Stephen Wilde, July 28, 2015 at 6:39 pm:
“Kristian is wrong.”
*Sigh* Yeah, I thought you might like that source. I’ve discussed lgl’s peculiar “finding” with him at the site where he first brought it to our attention. It’s wrong. In fact, it’s stupidly so.
This Hay-fellow (as esteemed as he might be) does two fundamental (and quite amateurish) mistakes:
1) Like you, he cannot separate between ‘heat’ [Q] and ‘internal energy’ [U], and therefore cannot understand that energy is in fact lost and gained by the system during the adiabatic cycle, through ‘work’ [W] performed on and by the system, by and on its immediate surroundings.
2) Like you, he thinks by doing thermodynamic ‘work’, KE is somehow simply transformed to PE inside the system performing the work, instead of that system actually spending the energy while performing the work. In thermodynamics, when you do ‘work’, you use energy and you transfer it to the system that you do the work on. You do not just tranform some of your own internal energy from KE to PE. That’s not just ridiculous. It’s simply un-physical. Contrary even to Newton! If you do work and don’t transfer energy to the thing your doing work on, then you are not doing work, because you cannot accomplish any change.
Both of these points are elementary in thermodynamics (the second one even in Newtonian mechanics). Especially the second one is an egregious mistake to make. Simply because it’s so obvious.
BTW, Stephen, me and several others have provided you with an avalanche of sources over the years who say exactly the opposite to this one guy. You have never acknowledged even a single one of them.
I have seen a couple of other sources displaying the same kind of fundamental miscomprehension of this issue as this one does. They do exist, for sure. But they are (luckily) rare. All educational texts on the subject (i.e. the things actually taught at universities all around the planet) say the same thing, very consistently. I’ve shown you tens upon tens of examples of what they say before, and I know it’s still no use, because you just go lalalalalala anyway, but here are two more (randomly picked):
http://www.geog.ucsb.edu/~joel/g110_w08/lecture_notes/cooling_processes/cooling_processes.html
http://snowball.millersville.edu/~adecaria/ESCI107/esci107_lesson05_stability.pdf
From the first source:
From the second source:
I can keep going …
Read my post at 10.52 pm
Why? You clearly didn’t read my post. Once again it’s right there in front of you. In black and white. And you just ignore it. And move on with you own personal takes on science, physics and reality. It’s hopeless.
Here’s another source to enlighten you (one you should really read through thoroughly):
http://farside.ph.utexas.edu/teaching/sm1/lectures/node56.html
I will remind you once again, that ‘work’ in thermodynamics is defined like this:
https://en.wikipedia.org/wiki/Work_(thermodynamics)
Worth noting from the same source (for you in particular, Stephen, who seems to have a complete blind spot when it comes to differentiating between the transfer of energy as ‘heat’ [Q] to/from the system, the transfer of energy as ‘work’ [W] to/from the system, and the energy held inside the system, the ‘internal energy’ [U]):
http://www.geog.ucsb.edu/~joel/g110_w08/lecture_notes/cooling_processes/first_law.gif
See, Stephen? Two different types of energy transfer. In an adiabatic process, only the arrows to the left, the ‘heating’ [Q], is defined as zero, not the arrows to the right, the ‘working’ [W]. Because the ‘working’ arrows involve the expansion and the contraction of the air parcel, against a reduced and an increased outside air pressure respectively.
The energy inside the parcel is NOT what’s called ‘heat’. That’s ‘internal energy’, the U.
Any source which refers to work in an adiabatic process being done on the surrounding air is wrong.
The usual terminology is ‘surroundings’ or ‘environment’, both of which which accommodate
the gravity field.
You might try this:
http://hockeyschtick.blogspot.ca/
Given a choice between you and Feynman the decision is obvious 🙂
Stephen Wilde, July 29, 2015 at 3:35 am:
“Any source which refers to work in an adiabatic process being done on the surrounding air is wrong.
The usual terminology is ‘surroundings’ or ‘environment’, both of which which accommodate
the gravity field.”
Of course, if Professor Stephen Wilde says so, we have accomplished instant Truth. It just has to be so. His words alone do magic. They turn things into facts by simply being stated.
So the cooling of the air inside a cylinder as the piston relaxes and falls back is not adiabatic. The cooling of the air coming out of a punctured tire is not adiabatic. The cooling and resulting condensation of CO2 as it comes out of a fire extinguisher is not adiabatic. Because the expansional work done by the gases in all these examples are performed on the surrounding air and not on the gravity field. And so they are not adiabatic. According to Professor Stephen Wilde. If gravity doesn’t cool the gas, then it’s not adiabatic cooling. It’s … something else.
Yup. Welcome to the cuckoo’s nest!
Strange, then, how NONE of the educational texts and lectures on the adiabatic process in the atmosphere EVER mentions the ‘gravity field’ as a player, don’t you think? How the ‘surroundings’ or the ‘environment’ is NEVER specifically stated to include the gravity field.
Or, I guess you just have to know that, don’t you, Professor Stephen? It will never be stated. It’s just a hidden fact that only a few are allowed to utter. Right?
The expansion of the air parcel is done against the surrounding pressure, Stephen. The outside pressure of the air immediately surrounding the air parcel. That is what is stated. Again and again and again. Gravity is never mentioned.
Looks like my reply to Kristian tripped the moderation filter so I hope the mods approve it shortly.
While I wait for my full reply to be released I’ll just mention this :
Kristian said:
“The expansion of the air parcel is done against the surrounding pressure, Stephen. The outside pressure of the air immediately surrounding the air parcel. That is what is stated. Again and again and again. Gravity is never mentioned.”
If the ambient pressure were the same as or higher than the pressutre in the ascending parcel then you would be right.
However, gravity sets up declining pressure with height so the ascending parcel is expanding into a region of lower pressure.
Thus the surrounding molecules present no resistance and no work is done against them by the rising parcel which simply expands into the space made available by the lower pressure.
The only work that needs to be done is against gravity as the molecules move apart to fill the space made nrewly available during the ascent.
Try resubmitting that with a URL shortener and less caustic language
I’m just looking at this from the perspective of a layman quant with expertise elsewhere but for whom only quantitative relationships count .
Even the importance of the total energy impinging on an orbit has been so suppressed in this field that I’m not sure whether Kristian will agree that at the top of an atmosphere the temperature must converge on the temperature corresponding to that total — in the case of Venus , about 328K , Earth , 279K .
The next parameter to be considered is the planet’s spectrum as seen from the outside and its correlation w that of the Sun .
After that , and in many ways the big mystery is how heat can actually be “trapped” . How can the interior of a ball remain perpetually hotter than the temperature calculated for its surface ?
This discussion , and Hockey’s calculations and observational confirmation ( and Kristian’s graphs ) — which I have yet to work thru and implement myself , and probably won’t for at least a month , has made it clear that gravity is the force which cannot be ignored .
It is the next non-optional parameter .
It doesn’t matter the details , it is the sum of gravitational ( considered a negative ) and thermal energy which must be in balance with impinging radiation . Working out the equations should be , and apparently are , fairly simple from there .
But this is a basic change in world view . It extends to the very center of a ball . It means that even without radioactivity , the core of the earth will always be far hotter , by an easily calculable amount , than the surface as long as the Sun shines .
I wonder if Chandrasekhar covers this . I think he must .
Bob,
The interiors of large enough solid objects do indeed heat up as a consequence of gravity compressing the matter of which they are composed to a density higher than the molecular bonds would otherwise determine.
It is the struggle between the force of gravity and the molecular bonds that generates the kinetic energy.
That is part of the general physical characteristics of matter throughout the universe and if the aggregations of matter are large enough one gets the creation of suns when the force of gravity generates enough interior heat through the compression of matter to let fusion commence. Ultimately one can achieve creation of black holes (if they do actually occur).
The thing is, though, that it takes a lot more mass and much stronger gravity to create heat within solids and liquids than in gases simply because gases are magnitudes more compressible and so generate kinetic energy within a gravitational field much more readily than do liquids and solids.
I don’t think any of this is new since I learned it decades ago.
What seems to have happened is that the link between such astronomical processes involving planets and suns and the similar but magnified effect within gases has not been noticed by those climatologists who try to explain everything in terms of radiative balances.
That link was known decades ago because I was always taught that the high surface temperature of Venus was due to the compression of dense gases by gravity, long before anyone tried to explain it with radiative theory.
Stephen/Bob – As the planet compressed there was f*d energy increase; infalling matter brought KE with it. After this process completed there is f of gravity but no f*d (i.e. f*0) so no energy increase any longer except by radioactive decay which has f*d in itself.
Bob’s global surface Tmedian 279K comes from incorrectly considering the global atmosphere emissivity 0.6 when it has been actually measured ~0.7 looking up in coldest, dry polar regions and .95 in humid tropics. Confirmed by lowest DW IR recorded in polar regions around 130W/m^2 , where 0.6 would result in DW IR substantially lower around 102 W/m^2 which has never been observed naturally anywhere.
Tridk : “Bob’s global surface Tmedian 279K comes from incorrectly considering the global atmosphere emissivity 0.6 ”
NO ! . Absolutely totally WRONG .
It simply comes from adding up ( integrating ) all the radiant energy impinging on a point in our orbit .
Watch my Heartland presentation on How to Calculate the Temperature of a Radiantly Heated Colored Ball ,
http://climateconferences.heartland.org/robert-armstrong-iccc9-panel-18/ if you don’t understand why that is the only computationally relevant value .
The next parameter after that to be added to the computation is the full spectrum of the planet as seen from space . It is retarded , as I have pointed out above and elsewhere to keep perseverating on crude step function hypothetical spectra when actual measured spectra are available .
“As the planet compressed there was f*d energy increase; infalling matter brought KE with it. After this process completed there is f of gravity but no f*d (i.e. f*0) so no energy increase any longer except by radioactive decay which has f*d in itself.”
Depends on the size of the aggregation of mass of the planet. I didn’t commit myself as regards Earth because I don’t know the answer.
I’m going to cc Alan Guth on this .
I got to get ready for my closest Saturday to MidSummer 3 days hence .
Stephen , The thing is , I always thought of the gravitation heating as being a dynamic heating of accretion . But , given an external radiant source , the interior has to be hotter by the calculated gravitational energy than that calculated for its surface to be in radiative balance with that source .
Thus Kelvin needed not have worried that the Earth’s core would ever cool to its surface temperature .
I really look forward to having time to explore the computations , but for right now my priorities are more about testing that the function I made yesterday in my open and free 4th.CoSy to count the portion of Nobel laureates willing to sign onto CAGW :
: PoT 1p R@ R@ +/ %f 1P> ; | Proportions of Totalf( 30 35 )f PoT |>| 0.46153 0.53846
works perceptually instantaneously on a string of a million numbers and doesn’t bomb using my new stack frame definitions of those parameter push and Pop fns .
Bob 12:25pm – I have listened to your lecture and looked through your .ppt with obtuse nomenclature.
I will stand by what I wrote.
For instance, you multiply temperature on slide 24. This would imply 2 cups of room temperature water combined can multiply 2 * 72 = 144F. Not true. So 0.98*279K is not 273.4K.
Your chart on slide 11 gives no source, T does not appear to be correct from the usual sources.
You simply announce the 279K which is equiv. to global near surface Tmedian calculated from atm. at 0.6 emissivity looking up from surface on a simple balance (see e.g. Bohren 2006 text p. 33), no calculation given, no source. In fact I see no source given for any of the data.
I’m sorry you do not follow the computation of the temperature of a gray , flat spectrum object in our orbit simply from the temperature and radius of the Sun and our distance from it .
I spend a couple of slides on why the notation . In such APLs a functioning model of planetary physics can be written as succinctly as it can be expressed in any physics text . My friend Morten Kromberg recently gave a Google Tech Talk on his company’s APL which may help understand why these notations are worth learning : https://www.youtube.com/watch?v=PlM9BXfu7UY . I understand that Roy Spencer’s new system , still in FORTRAN , is under 10,000 lines . I consider that a remarkable achievement and clearly has to deal with a score of factors . In well written APL , I cannot imagine it taking much more than a hundred lines — mostly brief definitions . All of the code for the computation of equilibrium temperature of a ball with an arbitrary absorption=emission spectrum and arbitrary source spectrum are contained on the my slides .
You think I really need references for this slide :
http://cosy.com/Science/CO2vTkelvin.jpg
I believe it is universally accepted that our temperature has change from about 288K to 289K while CO2 has gone from about 290ppm to 390ppm . What’s to reference ?
Your comment on this slide
http://cosy.com/Science/WaterEquilibriumTemp.jpg
makes me wonder if you understand slide 10 which explains what I consider a grade school fact that only the 0 based Kelvin scale is useful in multiplicative computations .
Frankly , you come across to me as symptomatic of the utter retardation of the understanding of essential undergraduate math endemic in this field , prerequisite in any any other branch of applied physics , eg , semiconductors .
“You think I really need references for this slide :”
Yes. With citation.
“What’s to reference ?
The source of the data.
“..a grade school fact that only the 0 based Kelvin scale is useful in multiplicative computations .”
You can talk about delta temperature in grade school, 289K being 1K higher than 288K. Cannot multiply, cannot add 72F to 72F to get 144F, or zero based 288K + 288K = 576K.
https://en.wikipedia.org/wiki/Intensive_and_extensive_properties
“…makes me wonder if you understand slide 10…”
Let me remove all wonder, I do not understand slide 10. Fill me in. Start with what altitude is the 279K you discuss, is it global, annual spatial & temporal avg.? What? And what is a flat spectrum in the context of climate?
To claim that it is “accepted that our temperature has change from about 288K to 289K while CO2 has gone from about 290ppm to 390ppm .” needs some specific reference is just silly among this audience . I use the word “about” twice because the point is simply that dT%dCO2 at these concentrations is at most on the order of 0.01 .
I am NOT multiplying or adding 2 temperatures . I am multiplying the gray body temperature by the 4th root of a ratio of dot products . Perhaps my best phrasing so far in at http://cosy.com/Science/RadiativeBalanceGraphSummary.html :
The conversion of that statement of balance to the product of the gray body temperature times the 4th root of the ratio of absorption to emission is the subject of slide 23 , http://cosy.com/Science/AGWppt_AEratioCalc.jpg . Martin Hertzberg derives the same formula in a less general way .
I’m curious if you know what a dot product is . It is arguably the most fundamental computation of existence .
It appears to me that you have learned to parrot the 33K meme while never learning how to calculate the value for any arbitrary spectra . This should be absolutely core curriculum for anybody claiming even college level expertise in the field . The ubiquitous ignorance of even these most basic non-optional computations is what drove me to divert a painfully costly amount of time and energy into this battle against tyrannical nonscience .
Trick ,
I see you are right that my description of the necessity of 0 based scales is insufficient . Of course it is computations in energy , ie ,
T ^ 4which are linear . That’s why its the 4th root of the absorption%emission ratio which is used in the computation in terms of temperature .I’m surprised the phrase I commonly use “gray body in our orbit” is ambiguous . And I explicitly state it is calculated simply by summing the total energy impinging on a point in our orbit . It has nothing to do with atmosphere or observed Earth temperatures at some altitude or whatever . It is simply the StefanBoltzmann temperature calculated from the observed temperature of the Sun and the portion of the celestial sphere it subtends viewed from our orbit . It is the same for any shade gray from black
ae = 1to almost white ( there is a singularity , of course atae = 0) .Trick ,
I thought of another way to relate the 279K value to something you know . ( but also which I hoped my graph at July 22, 2015 at 6:24 pm tried to make clear . It’s the temperature corresponding to total top of atmosphere insolation . In 4th.CoSy current reverse Polish given the Stefan Boltzmann constant , 5.670373e-8 :
279. 4. ^ 5.670373e-8 * |>| 343.58 | 279K correspond to ~ 343.58 w%m^2 over the sphere .
343.58 4. * |>| 1374.32 | multiplying by ratio of surface of sphere to that of disk .
Does that make it clear ?. It’s the temperature of a sphere in our orbit before any spectral parameter is considered . It is what Wikipedia and NASA should label the black body
==gray body temperature .“I am NOT multiplying or adding 2 temperatures .”
This sure appears to be your doing so on the slide: 0.98 * 279 for 273.4. You are multiplying a number & temperature, which has no meaning as in 2 * 288K = 586K is not correct.
You are right that you cannot add temperatures without taking their 4th power to convert to energy in which computations are linear and then taking the 4th root .
However in Kelvin it does make sense to multiply and divide . It makes perfect sense to say that 200K is 2 times 100K . Note the multiplier 2 is dimensionless . It makes perfect sense because
200 ^ 4is2 ^ 4times100 ^ 4.“It makes perfect sense to say that 200K is 2 times 100K .”
You can do the calculation Bob, but no physical sense is made, unless you can demonstrate 200K water ice added to 200K water ice creates a a mix of liquid water boiling away at 400K.
What level are you at in school ? I hope it is not beyond high school .
There are some very basic issues you fail to understand .
Saying one temperature is twice another is NOT the same thing that if you add one mole of water to another mole of water at the same temperature the 2 moles of water will be 2 times the temperature .
You demonstrate that you DO NOT understand the necessity and import of the Kelvin scale .
Bob – It is you on your slide saying that not me! with your multiplying a temperature in K by a factor, you need to correct that slide. Then I’ll have a look at the rest.
I conclude that you have never had a college level or even good highschool level physics class .
By your (ill)logic even a thermometer would be impossible . Think about it . There is only an affine transformation between temperature scales .
You are coming close to revealing yourself to be a willfully dishonest troll .
Bob – Nothing to do with a thermometer. You multiplied a number by a temperature on your slide, I explained this is nonphysical, intensive properties include temperature. Pretty simple: your slide showing 0.98 * 279 for 273.4 needs to address this issue.
You are a willful troll who fails even high school math .
F
I’ll simplify and shorten the whole thing and repost shortly.
Kristian said:
“Strange, then, how NONE of the educational texts and lectures on the adiabatic process in the atmosphere EVER mentions the ‘gravity field’ as a player, don’t you think? How the ‘surroundings’ or the ‘environment’ is NEVER specifically stated to include the gravity field.”
One of your own links over at Tallbloke’s said this:
“there are two separate kinds of work being done here. Simply because we’re operating in a gravity field”
In relation to which I commented to you:
“The first kind of work is the raising vertically.
The second kind of work is the moving apart of molecules into lower pressure.
Both involve work against gravity and NOT against surrounding molecules. The link says as much since both types of work are explicitly mentioned as a consequence of ‘operating in a gravity field’.”
And there is this item:
http://hockeyschtick.blogspot.co.uk/
which discusses work against gravity in some detail.
All the authoritative sources emphasise the importance of gravitational acceleration in connection with adiabatic uplift and descent but I accept that some sources, misleadingly, do refer to work being done against surrounding molecules and that has caused your understanding to be faulty.
The examples you give are not applicable since they do not involve changing height within the gravitational field.
Stephen 9:58am: “The first kind of work is the raising vertically. The second kind of work is the moving apart of molecules into lower pressure. Both involve work against gravity and NOT against surrounding molecules.”
Both are in the math of the ELR, neither in DALR math.
Yes, the “first kind” is for ELR parcels considered ascending and descending in a gravity field.
The “second kind” though is independent against the force between molecules (not against gravity force) resulting in the p*v term, which you don’t acknowledge, from Maxwell’s reasoning and test around 1870. Here P of the air inside Kristian’s diagram may not equal Ps so there is a force over a distance called working in Kristian’s diagram when that is the case in the ELR, since v also changes the energy exchanged in the “working” arrows is p*v. This is not allowed in DALR since its math holds P=Ps so no force exists over the distance (which does exist).
Also there is thermal energy crossing the border as in Kristian’s diagram called “heating” both ways if T not equal Ts.
All of the energy crossing the border can be accounted for as conserved with z height changing & along with the existing internal energy (KE+PE), the sum of which with p*v term is called the “dry static energy” the proper conserved quantity – not just KE+PE being conserved as in your improper imagination that doesn’t line up with test.
You can find all this in a good text, in math and prose, internet links are subject to increased error propagation. Texts suffer that disease too, one appreciates the texts quoting the original work an increase of “goodness”. As I mentioned to you long ago.
Trick said:
“The “second kind” though is independent against the force between molecules (not against gravity force) resulting in the p*v term, which you don’t acknowledge”
Not correct.
The force between molecules has already been adjusted by the gravity field creating a declining pressure gradient with height. Gravity has previously done the necessary work on the molecules along the lapse rate slope so as to account for the p*v term even before uplift commences.
Thus there is no residual force between molecules opposing the expansion of a rising parcel when the expansion is into a region of lower density. The rising parcel simply expands to match the new ambient pressure and density.
That leaves the only force opposing expansion during uplift as the downward pull of gravity.
The necessary work of expansion is therefore done against that downward force.
As regards the rest of your post it is not relevant here. It is not disputed that there is some thermal leakage in and out of ascending parcels but that is a diabatic not an adiabatic process.
So Stephen – Do you have a proper test to go with your assertion(s)?
The ELR is always diabatic, the DALR always T=Ts and P=Ps so both Kristian’s arrows are 0.
The ELR is not all diabatic but it always has a diabatic component.
It is only diabatic to the extent that it diverges from the pure ALR determined by mass and gravity.
Even the DALR is partly diabatic because all matter has some radiative capability which allows leakage out from the adiabatic process.
Convection then adjusts to negate the diabatic components so that on average over time the ALR is achieved and the atmosphere retained.
The method of convective adjiustment is described here:
http://hockeyschtick.blogspot.co.uk/2015/07/erasing-agw-how-convection-responds-to.html
Stephen – nothing in nature is adiabatic, so it appears you have no tests backing your assertions, that site didn’t have any, your assertions remain speculative at best unsupported.
Nothing is purely adiabatic but there is adiabatic uplift and descent in so far as the work done is done against gravity.
Not even adiabatic uplift, ruled out by second law.
Don’t be silly.
http://eesc.columbia.edu/courses/ees/climate/lectures/atm_phys.html
With regard to the link I just gave you this is interesting since it may go some way to explaining Kristian’s confusion:
“As our air parcel expands in response to the lowering of the outside pressure, the force of its internal pressure is moving the walls of the container outwards. When a force is moving an object over a given distance it does work. Thus the expanding air parcel does work on its surroundings. This work must come at the expense of internal energy (remember, heat is neither added nor taken away from the parcel in this experiment). Thus the molecular motion within the parcel will slow down, and the parcel’s temperature will drop. ”
Note firstly that they previously referred to internal energy as kinetic energy only whereas potential energy should really be included. No doubt that was done for simplicity.
Note secondly that they refer to the walls of a flexible container and it is the walls of the container that are pushed out and NOT outside molecules being pushed away. There is no need to push outside molecules away because the lowered pressure outside the parcel has removed all resistance to expansion.
If there is no flexible container then the walls are effectively the outermost layer of molecules of the parcel and they cross a distance in response to the higher internal pressure of the parcel, not meeting any resistance along the way.
Work is done moving the molecules across the distance so it is that distance, that additional volume , which is the surroundings and NOT molecules outside the parcel.
In the process of crossing that distance work has to be done against the gravitational field which is constantly seeking to pull the parcel back down and compress it once more.
It really is obvious that the relevant work is being done against gravity but people such as Kristian and even providers of some source materials have misunderstood the position and simply assumed, incorrectly, that work against external molecules was required.
Stephen – My stuff agrees with that link, so nothing silly. In that link you don’t discuss the “outs” afforded by the discussion:
“the expanding air parcel does work”
Here they are discussing the ELR as Kristian’s arrows for working are stated non-zero, in contrast the DALR derivation the working arrows are 0 since P=Ps. This is a clue you miss all the time it seems.
“It really is obvious that the relevant work is being done against gravity”
Yes, for the ELR.
“the ideal gas law (ideal because it is not exact..”
IGL is ideal, not exactly reality. The adiabatic lapse rate DALR is NOT measured, the ELR is:
“The measured local vertical profile of temperature in the air is called the environmental lapse rate.”
Measured is real world.
“..rising air cools adiabatically…”
Here in context they are discussing the DALR with T=Ts and P=Ps.
“Water vapor is an absorber of infrared radiation..”
See? They even discuss mixing ratio – a term I have used. This link is ok but not “good” as it just announces things without telling us the original sources that relied on test for the “things” originally said, which is very unsatisfying.
Anthony Watts. It is the ROTATION that is the difference.
1) average temperature is irrelevant. We blow through it in a second twice per day. The Earth has a day temperature and a night temperature.
2) Compare the Moon and the Earth temperatures. The moon has much higher day temperatures and much colder night temperatures due to its lack of atmosphere and slow rotation.
3) Rotation. This is the key difference between the Earth and Venus. The Earth rotates in 24 hours. Venus, what I’d it 300 plus days?
4) Venus day/night cycle is extreme, like the moons, because of its long day/night cycle.
5) Venus would be much cooler if it rotated ever 24 hours.
The most profound effect of an atmosphere , and GHGs is to reduce diurnal variance . But I have never seen an analysis of this effect which vastly exceeds any effect on the mean .
My understanding is , and what made be believe Venus’s surface temperature must be due to internal heating , that it’s pre-dawn temperature is almost indistinguishable from it’s evening temperature ~ 114 days earlier .