Guest Post by Willis Eschenbach
I’ve been reflecting over the last few days about how the climate system of the earth functions as a giant natural heat engine. A “heat engine”, whether natural or man-made, is a mechanism that converts heat into mechanical energy of some kind. In the case of the climate system, the heat of the sun is converted into the mechanical energy of the ocean and the atmosphere. The seawater and atmosphere are what are called the “working fluids” of the heat engine. The movement of the air and the seawater transports an almost unimaginably large amount of heat from the tropics to the poles. Now, none of the above are new ideas, or are original with me. I simply got to wondering about what the CERES data could show regarding the poleward transport of that energy by the climate heat engine. Figure 1 gives that result:
Figure 1. Exports of energy from the tropics, in W/m2, averaged over the exporting area. The figures show the net of the energy entering and leaving the TOA above each 1°x1° gridcell. It is calculated from the CERES data as solar minus upwelling radiation (longwave + shortwave). Of course, if more energy is constantly entering a TOA gridcell than is leaving it, that energy must be being exported horizontally. The average amount exported from between the two light blue bands is 44 W/m2 (amount exported / exporting area).
We can see some interesting aspects of the climate heat engine in this graph.
First, like all heat engines, the climate heat engine doesn’t work off of a temperature. It works off of a temperature difference. A heat engine needs both a hot end and a cold end. After the working fluid is heated at the hot end, and the engine has extracted work from incoming energy, the remaining heat must be rejected from the working fluid. To do this, the working fluid must be moved to some location where the temperature is lower than at the hot end of the engine.
As a result, there is a constant flow of energy across the blue line. In part this is because at the poles, so little energy is coming from the sun. Over Antarctica and the Arctic ocean, the sun is only providing about a quarter of the radiated longwave energy, only about 40 W/m2, with the remainder being energy exported from the tropics. The energy is transported by the two working fluids, seawater and air. In total, the CERES data shows that there is a constant energy flux across those blue lines of about six petawatts (6e+15 watts) flowing northwards, and six petawatts flowing southwards for a total of twelve petawatts. And how much energy is twelve petawatts when it’s at home?
Well … at present all of humanity consumes about fifteen terawatts (15e+12) on a global average basis. This means that the amount of energy constantly flowing from the equator to the poles is about eight-hundred times the total energy utilized by humans … as I said, it’s an almost unimaginable amount of energy. Not only that, but that 12 petawatts is only 10% of the 120 petawatts of solar energy that is constantly being absorbed by the climate system.
Next, over the land, the area which is importing energy is much closer to the equator than over the sea. I assume this is because of the huge heat capacity of the ocean, and its consequent ability to transport the heat further polewards.
Next, overall the ocean is receiving more energy than it radiates, so it is exporting energy … and the land is radiating more than it receives, so it is getting energy from the ocean. In part, this is because of the difference in solar heating. Figure 2, which looks much like Figure 1, shows the net amount of solar radiation absorbed by the climate system. I do love investigating this stuff, there’s so much to learn. For example, I was unaware that the land, on average, receives about 40 W/m2 less energy from the sun than does the ocean, as is shown in Figure 2.
(Daedalus, of course, would not let this opportunity pass without pointing out that this means we could easily control the planet’s temperature by the simple expedient of increasing the amount of land. For each square metre of land added, we get 40 W/m2 less absorbed energy over that square metre, which is about ten doublings of CO2. And the amount would be perhaps double that in tropical waters. So Daedalus calculates that if we make land by filling in shallow tropical oceans equal to say a mere 5% of the planet, it would avoid an amount of downwelling radiation equal to a doubling of CO2. The best part of Daedalus’s plan is his slogan, “We have to pave the planet to save the planet” … but I digress).
Figure 2. Net solar energy entering the climate system, in watts per square metre (W/m2). Annual averages.
You can see the wide range in the amount of sunlight hitting the earth, from a low of 48 W/m2 at the poles to a high of 365 W/m2 in parts of the tropics.
Now, I bring up these two Figures to highlight the concept of the climate system as a huge natural heat engine. As with all heat engines, energy enters at the hot end, in this case the tropics. It is converted into mechanical motion of seawater and air, which transports the excess heat to the poles where it is radiated to space.
Now, the way that we control the output of a heat engine is by using something called a “throttle”. A throttle controls the amount of energy entering a heat engine. A throttle is what is controlled by the gas pedal in a car. As the name suggests, a throttle restricts the energy entering the system. As a result, the throttle controls the operating parameters (temperature, work produced, etc.) of the heat engine.
So the question naturally arises … in the climate heat engine, what functions as the throttle? The answer, of course, is the clouds. They restrict the amount of energy entering the system. And where is the most advantageous place to throttle the heat engine shown in Figure 2? Well, you have to do it at the hot end where the energy enters the system. And you’d want to do it near the equator, where you can choke off the most energy.
In practice, a large amount of this throttling occurs at the Inter-Tropical Convergence Zone (ITCZ). As the name suggests, this is where the two separately circulating hemispheric air masses interact. On average this is north of the equator in the Pacific and Atlantic, and south of the equator in the Indian Ocean. The ITCZ is revealed most clearly by Figure 3, which shows how much sunlight the planet is reflecting.
Figure 3. Total reflected solar radiation. Areas of low reflection are shown in red, because the low reflection leads to increased solar heating. The average ITCZ can be seen as the yellow/green areas just above the Equator in the Atlantic and Pacific, and just below the Equator in the Indian Ocean.
In Figure 3, we can see how the ITCZ clouds are throttling the incoming solar energy. Were it not for the clouds, the tropical oceans in that area would reflect less than 80 W/m2 (as we see in the red areas outlined above and below the ITCZ) and the oceans would be much warmer. By throttling the incoming sunshine, areas near the Equator end up much cooler than they would be otherwise.
Now … all of the above has been done with averages. But the clouds don’t form based on average conditions. They form based only and solely on current conditions. And the nature of the tropical clouds is that generally, the clouds don’t form in the mornings, when the sea surface is cool from its nocturnal overturning.
Instead, the clouds form after the ocean has warmed up to some critical temperature. Once it passes that point, and generally over a period of less than an hour, a fully-developed cumulus cloud layer emerges. The emergence is threshold based. The important thing to note about this process is that the critical threshold at which the clouds form is based on temperature and the physics of air, wind and water. The threshold is not based on CO2. It is not a function of instantaneous forcing. The threshold is based on temperature and pressure and the physics of the immediate situation.
This means that the tropical clouds emerge earlier when the morning is warmer than usual. And when the morning is cooler, the cumulus emerge later or not at all. So if on average there is a bit more forcing, from solar cycles or changes in CO2 or excess water vapor in the air, the clouds form earlier, and the excess forcing is neatly counteracted.
Now, if my hypothesis is correct, then we should be able to find evidence for this dependence of the tropical clouds on the temperature. If the situation is in fact as I’ve stated above, where the tropical clouds act as a throttle because they increase when the temperatures go up, then evidence would be found in the correlation of surface temperature with albedo. Figure 4 shows that relationship.
Figure 4. Correlation of surface temperature and albedo, calculated on a 1°x1° gridcell basis. Blue and green areas are where albedo and temperature are negatively correlated. Red and orange show positive correlation, where increasing albedo is associated with increasing temperature.
Over the extratropical land, because of the association of ice and snow (high albedo) and low temperatures, the correlation between temperature and albedo is negative. However, remember that little of the suns energy is going there.
In the tropics where the majority of energy enters the system, on the other hand, warmer surface temperatures lead to more clouds, so the correlation is positive, and strongly positive in some areas.
Now, consider what happens when increasing clouds cause a reduction in temperature, and increasing temperatures cause an increase in clouds. At some point, the two lines will cross, and the temperature will oscillate around that set point. When the surface is cooler than that temperature, clouds will form later, and there will be less clouds, sun will pour in uninterrupted, and the surface will warm up.
And when the surface is warmer than that temperature, clouds will form earlier, there will be more clouds, and higher albedo, and more reflection, and the surface will cool down.
Net result? A very effective thermostat. This thermostat works in conjunction with other longer-term thermostatic phenomena to maintain the amazing thermal stability of the planet. People agonize about a change of six-tenths of a degree last century … but consider the following:
• The climate system is only running at about 70% throttle.
• The average temperature of the system is ~ 286K.
• The throttle of the climate system is controlled by nothing more solid than clouds, which are changing constantly.
• The global average surface temperature is maintained at a level significantly warmer than what would be predicted for a planet without an atmosphere containing water vapor, CO2, and other greenhouse gases.
Despite all of that, over the previous century the total variation in temperature was ≈ ± 0.3K. This is a variation of less than a tenth of one percent.
For a system as large, complex, ephemeral, and possibly unstable as the climate, I see this as clear evidence for the existence of a thermostatic system of some sort controlling the temperature. Perhaps the system doesn’t work as I have posited above … but it is clear to me that there must be some kind of system keeping the temperature variations within a tenth of a percent over a century.
Regards to all,
w.
PS—The instability of a modeled climate system without some thermostatic mechanism is well illustrated by the thousands of runs of the ClimatePredictionNet climate model:
Note how many of the runs end up in unrealistically high or low temperatures, due to the lack of any thermostatic control mechanisms.
Konrad 5:27pm, Kristian 12:08pm: “… it has taken “Trick” over a year to concede..”
I haven’t conceded. The discussion long ago was for an adiabatic column. Konrad’s recent construct leaves out the word “adiabatic”.
Plug in a trick solar powered heater orbiting at say just below thermopause and plug in same model at the surface; I concur the relative height will be critical to determining the avg. temperature of the gas column.
Kristian 10:53pm: “I know full well that you (Konrad) are one of the few around who actually think that CO2 is incapable of warming the Earth system. I’m another one.”
Count me in. I’m another one.
Added IR active gas ppm has a logarithmic decreasing mechanism to increase surface atm. constituents KE (Tmean) while identical decrease of KE (Tmean) at great height occurs so added CO2 is incapable of warming the Earth system. Warming the Earth system takes a source energy reservoir to be used up, as the sun is using up hydrogen.
“And you cannot transfer heat from a cooler atmosphere to a warmer surface.”
Concur.
Can transfer energy though in such a real unforced process as long as entropy increases in the system control volume which it does for the real earth & atm. 345.6 +/- 9 W/m^2 avg. DWIR increases the entropy of the dirt&water surface.
Konrad implies the entropy from DWIR is unchanged over water so that hypothesis cannot be real.
. Stephen Wilde says:
“…the surface has a temperature that under the S-B law should radiate out to space more radiation than is received from space.”
So say, Venus has surface temperature that according to S-B law should radiate out to space more radiation than is received from space.
I am not sure what this means.
Planet because of their internal heat do radiate slightly more energy than they receive- but this is not related to S-B law.
Let start with wiki statement of S-B law:
“The Stefan–Boltzmann law, also known as Stefan’s law, describes the power radiated from a black body in terms of its temperature. Specifically, the Stefan–Boltzmann law states that the total energy radiated per unit surface area of a black body across all wavelengths per unit time (also known as the black-body radiant exitance or emissive power), is directly proportional to the fourth power of the black body’s thermodynamic temperature”
http://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law
So roughly power of flux [watts per sq meter] is proportional to the fourth power temperature.
And so if measure flux, you can convert it into temperature [Kelvin]. So if at the surface
one has flux of X, one determine temperature K. Or if one measure temperature one determine
amount watts per per square meter.
This does assume something is radiating into a vacuum. Not only does a blackbody have radiate into vacuum, but this blackbody is ideal body [something that doesn’t exist].
So all known real universe matter does not include such a blackbody, but select material could considered to be close to a blackbody for some purpose. So by making some material resemble a blackbody, and if you in a vacuum you use Stefan–Boltzmann law to measure the temperature of the Sun. Or you can measure the temperature of the Sun from Earth surface and use adjustments or models to get an estimate of Sun’s temperature.
So when we say the Solar flux above Earth atmosphere is 1360 watts per square meter we saying what Sun’s temperature would be if Sun were blackbody in accordance inverse square law per square meter of it’s surface. If is flat panel and pointed at sun, it would same temperature of the sun at Earth distance, so ideal blackbody in which only radiated energy towards the sun.
instead of flat surface radiating 1360 watts per square meter it would radiate 1/4 of these watts per square meter of it’s surface were spherical and ideal blackbody in vacuum
Or the Moon should radiate in total of about average of 340 watts per square meter.
All it’s reflected light, and all it’s IR radiation should equal to around 340 watts per square meter entire lunar surface area.
Or if the Moon were a ideal blackbody. Which means such moon would be invisible to human eyes, because only spectrum leaving such a moon is not in spectrum humans can see. It’s *uniform* temperature should about 278 K [5 C].
And contrary to what seems accepted practice in the pseudoscience, uniform temperature is not the same as average temperature. Or median average amount is not same as uniform amount.
One would think these socialist would understand the difference.
Socialist claim they want a uniform income for all people- this is their “equality”. Achieving median average is not something to achieve as one already has it in past, present, future have had and will have a median average income.
A reasonable person might think increasing the median average in income could be generally a good idea- something broadly in right direction for a society. So two billionaires are better than one billionaire, and 1000 is better than 2. But according to the theory having rich neighbors is the source most of evil in the world.
So an astonishingly stupid perversion of the issue of problems related to sin of envy. Though certainly involves a issue related to an explanation of The Terror which spawned the modern Left. If one imagine the The Terror as “good idea” or right direction, then it is in accordance with this “direction”. It’s true to this faith.
In terms global temperature, the Earth [or the Moon] is not uniformly warmed.
An design feature of ideal blackbody was to suppose it was uniformly warm a spherically body.
The fact of the earth is spinning and on an axis tilted 23 degrees is element which gives our world and more uniform temperature. But the stipulated design of blackbody does not *require*
any spin in order to have completely uniform temperature.
Another element of Earth which makes more towards an uniform temperature is the heat retaining ability of it’s ocean, land, and atmosphere.
A ideal blackbody has no stated attribute of storing heat- it’s irrelevant to the model.
So a spinning body and body retains heat are not important to the ideal blackbody,
but there certainly important real body in space in terms of a body having more uniform temperature. But for real body in space, neither make a significant difference in terms amount total energy striking the surface and a total energy leaving the surface. Obviously a planet doesn’t reflected or re-radiate more or less of the energy of the Sun. Nor does planet absorb more or less energy then it radiates. Broadly speaking, not factors such as geothermal energy of planet, or plant life absorbing more energy and is emitted burning this chemical energy, etc. So broadly speaking and so not including such relativity geological speaking short duration variations. So, it’s nothing more than restating that energy is generally, conserved.
Why I mention the above, is because the pseudoscience educated appear to think retaining of heat or spinning and axis tilt of world have nothing to do with global average temperature.
An interesting assumption about Venus is the idea, that it must have started out like Earth.
And we got same assumption with Mars.
Whether Venus or Mars had some water at some point in past billion years, is not the point I mean.
It’s the idea of these planets starting like Earth.
The idea that Mercury or our Moon started like
Earth is less common assumption, or it isn’t given much thought.
One could say we grew out of the idea that there could beings living on the Moon, but in mythology remained longer of hope of alien beings living on Mars and Venus.
Another part of it, is not that it started out as Earth of +4 billion years ago, but starting
out as essentially modern Earth.
What did Venus look like 4 billion year ago?
People can have to go on, but they can assume things which is based no evidence.
That was possibly even more of inferno from large impactors slamming into it at very high velocity, could be considered part of an educated guess.
One could make many stipulation about Venus it’s early history but why should it resemble anything like Earth of last 3 billion years to present?
it –Kristian 10:53pm: “I know full well that you (Konrad) are one of the few around who actually think that CO2 is incapable of warming the Earth system. I’m another one.”
Count me in. I’m another one.–
I am not certain. I think that doubling of CO2 has 0 C +/- .5.
And I think it’s a good chance we might get as much as 1 C to global average
temperature by 2100.
Whereas .5 C increase from being of 21 century to 2050 seems unlikely.
And so I think a .6 C increase from 2050 to 2100 is possibly or around
50% chance. So a 1.25 C more increase by 2100 I view as unlikely.
Of course I don’t think CO2 would why we get such increase or it’s
only a small part of why we could get such an increase.
Or I don’t think we will have 800 ppm CO2 by 2100- but nor is anyone
seriously suggesting that this is likely.
So I think we get less than .4 C of increase in global temperature by year
2100. And less than .3 C from CO2 by 2050.
This due to my guess that we will see the highest levels increase of CO2
emission by human before 2050, and highest driver of this increase will
be from China [just as it is has recently and to the present time].
The only one remotely capable of matching China emissions are Russia
and US, and it seems unreasonable to expect this from either of these
countries. China is burning 4 billion tons of coal.
“China – already the top consumer – will drive two-thirds of the growth in global coal use this decade. Half of China’s power generation capacity to be built between 2012 and 2020 will be coal-fired, said Woodmac.”
ttp://www.huffingtonpost.com/2013/10/14/world-coal-consumption-oil_n_4095221.html
And China eventually conceivable doubles it to 8 billion tonnes per year. It’s doubled
it in last decade, but unlike it will double it again within next decade, though
maybe within 2 decades. But it China will reach “peak Coal” some time within next
couple or perhaps 3 decades. If China gets to 8 billion tonnes it will have highest
will probably highest emission per capita in world. It seems more likely China will
peak at about 6 billion tonnes, though it’s seems possible reaching 8.
So seems that fracking would possibly have biggest effect on how much CO2
china emits. And there other elements which also lower global CO2. Beyond decade
one could have methane hydrate and/or Nuclear energy. But because both require
time develop, one will not see these having much effect within a decade.
So sems a given fracking will continue to grow and could become far more significant
within 10 years, global. And if China did [and it will not soon] it switch from coal to Methane,
it halves it’s emissions. And I would guess China only choice beyond 2050 is nuclear and/or methane.
And seems quite possible before 2050 global CO2 yearly emision could decline and leveling or decline of global CO2 level before 2100. And therefore global CO2 around 500 to 600 ppm.
And so we could be bit over 450 ppm be 2050. And if over 500 ppm by 2050, China would face political presure to do something drastic- despite whatever global temperature are, even if they lower than current global temperatures.
Willis, you once said this:
“I hold it can be proven that there is no possible mechanism involving gravity and the atmosphere that can raise the temperature of a planet with a transparent GHG-free atmosphere above the theoretical S-B temperature.”
So I ask you whether you agree that even for a GHG free atmosphere there would still be ‘surplus’ energy constantly recycling conductively between the surface and the mass of the atmosphere which would give a higher surface temperature than S-B predicts without affecting the net radiative balance at all.
The reason being that the S-B equation simply cannot be applied to a solid surface which is overlain by a gaseous atmosphere..
That gaseous atmosphere by virtue of its mass alone interferes with the free flow of radiative energy through the planet’s atmosphere because all mass has some radiative absorption capability in some part of the radiative spectrum.
It doesn’t have to be capable of absorption only in the IR wavelengths. It is sufficient for the mass of the atmosphere to absorb in any part of the spectrum for the mass induced greenhouse effect to occur. Whatever part of the spectrum is absorbed it is all converted to IR by the mass it encounters.
It matters not at all that a varying portion of the atmospheric mass tends to prefer to absorb in the IR bands because the mass induced greenhouse effect is not a result of that preference.
Rather it is the result of the interaction of atmospheric mass with every part of the incoming spectrum combined because that is what primarily slows down the transmission of solar energy through the atmosphere.
If there is a preference on the part of certain gases to absorb in the IR bands then that just affects the volume of the atmosphere and not the total length of the delay in transmission of solar energy through the system.
The only resistance to atmospheric expansion being gravity and gravity remaining constant any ‘extra’ IR can only go to expansion and not heating.
One cannot apply S-B to any surface unless there is no atmospheric mass at all above it.
It is conduction which invalidates the S-B equation and the conductive exchange which heats the surface further without altering the radiative balance between surface and space.
The cause of the so called greenhouse effect is the mechanical process of conduction and not radiation at all.
Actually it is even simpler so one can ignore my comments in my previous post about radiative capability except in so far as more such capability can only expand and not heat an atmosphere due to the lack of any constraint on expansion.
The warmer than S-B surface is all about conduction and mass resulting in convective overturning.
Nice enough presentation. Lots of people have been studying the heat flows through the system, and calling it a “heat engine” adds little. As a high-dimensional non-linear dissipative system with radiative output appx proportional to T^4, the climate does not need a throttle to stay within a range of temperatures. Complex dynamics (waves, vortices, etc) arise even in lower dimensional systems with uniform input on flat uniform surfaces, so in a system with 3 spatial dimensions complex flows of all kinds are to be expected — documenting those present in the Earth climate system is informative.
Whether the clouds do act as a throttle is an important question, but a throttle (or a thermostat) is not required to keep temperatures within bounds.
Stephen Wilde says:
December 28, 2013 at 1:18 am
“It matters not at all that a varying portion of the atmospheric mass tends to prefer to absorb in the IR bands because the mass induced greenhouse effect is not a result of that preference.”
—————
Now I can agree in principal with the above, …. but not with the following, to wit:
“Rather it is the result of the interaction of atmospheric mass with every part of the incoming spectrum combined because that is what primarily slows down the transmission of solar energy through the atmosphere.”
—————
And that is because the mass induced “greenhouse effect” is primarily the result of the interaction of atmospheric mass with the heated surface.
I changed my mind about the usefulness of the appellation “heat engine” — it might direct more people’s attention away from the fixation on “equilibrium”..
Stephen Wilde: Noted Willis but it’s not always easy to find specific quotes in a long thread or across multiple threads so paraphrasing is a useful time saver and it is always open to you to correct any misapprehension by restating your case rather than simply complaining about being misquoted.
I think it is implied in your previous words that all of the heat (temperature) at a surface is utilised in radiation to space and that there is no deduction for conduction.
Quote first then paraphrase. That way the rest of us can follow you as well.
Samuel C Cogar said:
“And that is because the mass induced “greenhouse effect” is primarily the result of the interaction of atmospheric mass with the heated surface.”
Agreed, hence my short follow up post at 2.01am
Matthew R Marler said:
“Quote first then paraphrase. That way the rest of us can follow you as well.”
Good suggestion but in the meantime I found a suitable quote and dealt with it at 1.18am thus:
“Willis, you once said this:
“I hold it can be proven that there is no possible mechanism involving gravity and the atmosphere that can raise the temperature of a planet with a transparent GHG-free atmosphere above the theoretical S-B temperature.”
So I ask you whether you agree that even for a GHG free atmosphere there would still be ‘surplus’ energy constantly recycling conductively between the surface and the mass of the atmosphere which would give a higher surface temperature than S-B predicts without affecting the net radiative balance at all”
Willis Eschenbach: Indeed they are. And not only that, they are what might be called “intelligent” heat sinks, in that they only form as and when they are needed to remove excess heat from the surface, and vanish when the job is done.
Indeed they might be called “intelligent”, as long as we remember the quotes in “intelligent”. No more insight is gained by calling them “intelligent” than is gained in calling the eyes of the eagles “intelligently designed”. We living creatures are lucky that the Earth has the qualities that it has, but the climate system is “self organized”. Other examples of “intelligent”: the Sun has been “intelligently” designed to maintain the Earth temperatures within a range; and the Earth orbit has been “intelligently” placed at just the right distance from the Sun.
For more desctiptions of some energy flows, peruse the book “Dynamic Analysis of Weather and Climate” by Marcel Leroux.
Have a happy and prosperous New Year. I hope you make time to provide more of these enlightening posts to the rest of us. You do a lot of good work.
Stephen Wilde: Good suggestion but in the meantime I found a suitable quote and dealt with it at 1.18am thus:
Thank you. I saw that. I hope you appreciate that it helps the rest of us to know what it is you are talking about.
The “pressure heads” are confusing pressure (static) with compression (dynamic process with energy transfer).
When I hand-pump the tire of my bike the pump becomes pretty hot as I am constantly compressing air – the increased pressure and temp are the result of the applied force that does the job.
Higher pressure by itself doesn’t imply higher temperature. For example, there are these pressure-cans or bottles at home, say for paint spraying, beer, champagne, in which the pressure is higher than the surrounding air but the temp is the same.
If you would prefer an astronomical counter example, black holes – can you imagine more pressure? yet they are very very cold see e.g. here.
If you would prefer an astronomical counter example, black holes – can you imagine more pressure? yet they are very very cold see e.g. here.
+++++++++++
I’m not sure the temperature of a black hole is very very cold. However, the radiation energy is not released due to immense gravity which pulls the radiation into the black hole. At least, that’s the way I see it.
lsvalgaard says:
December 22, 2013 at 2:33 pm
Willis Eschenbach says:
December 22, 2013 at 2:28 pm
The people I call “pressure heads” are those that think that on a planet with a GHG-free atmosphere, say an argon atmosphere, that pressure alone can raise the temperature of the surface.
All astronomers are then ‘pressure heads’ as it is generally accepted that pressure alone heated the Sun, as it formed out of a contracting cloud of interstellar gas, until it became so hot that nuclear fusion was initiated…
++++++++++++++++
I’m just enjoying reading through this post and I have a nit to pick.
Leif: I need to ask the following. Is pressure what now causes the sun to be hot? The answer is no, I think. The pressure was a temporary thing that happened as you say when the contracting cloud of gas occurred presumably due to gravity. Once the pressure is stabilized, the heat energy is no longer concentrated. I’m think of a can of soda, or Argon Dewar. The heat that was created during pressurization eventually goes away. The Dewar or can of soda is not an ongoing “source” of heat energy. The source of energy from the sun is from ongoing fusion processes, not from pressure.
I think what Willis is saying (correctly) [and these are my words] is that pressure does not cause the heating so much as it changes the temperature. However, that change in temperature is not new energy being created –rather its energy from somewhere else being concentrated such as to raise the temperature where there is more pressure. Then we have that wonderful latent heat of state changes which act as thermostats.
This stuff is so cool… uhm hot… uhm –OK I digress
A sphere in vacuum with ideal blackbody at Sun’s distance.
Has uniform temperature of 5 C. Or uniform temperature about 278 K.
And such sphere can spinning or not. Let’s say it’s tidal locked with sun so
same side is always facing the sun.
On Earth we call the equator as being perpendicular to the axis of spin.
This world spins at rate of one revolution per year [365 earth days].
So this sphere year about is 365 earth days long, and this sphere’s day
is forever.
This sphere could have any amount gravity and it still has uniform temperature
of 5 C. We will pick a gravity of 1 earth gravity.
So the one gravity sphere can be any size and this has little effect upon it’s uniform
temperature. But we say it’s same size as Earth.
Unlike earth not only does it not have changing day and night, since it doesn’t
have tilt it doesn’t have seasons- Winter, Spring, Summer, or Fall, anywhere on the
sphere..
The sphere does have equator it’s perpendicular to the axis of spin, and the permanent
noon at equator, always has the sun directly over head.
If you are on the sphere and have card table not made same material has this crazy
ideal blackbody. So any normal or typical card table. So have card table at noon equator
and put some of this crazy ideal blackbody material over the card table. Then the stuff
on card table will be about 123 C. And the ideal blackbody material on the ground will
5 C.
You have a fast vehicle. You travel west for one hour at 1000 miles per hour. So you at
about 11 am. Set up card table put ideal blackbody material on card table. And it’s about
123 C and ground is 5 C. And sun is 75 degree above horizon or 15 degree off zenith.
Get in vehicle and travel another hour. Sun is 60 degree above horizon. Table is still about
123 C. And it’s 10 am.
Get vehicle travel hour. it’s 9 am. Sun at 45 degrees. Could be bit cooler
than 123 C.
Get in vehicle. Travel another hour. 8 am. Sun at 30 degree angle. And it cast a shadow twice
your length. If you see such a shadow on this crazy material that looks like you be looking into a dark cave.
Now the blackbody material on card is not 123 C
It’s about 50 C. If tilt the table by 15 degree or more. Then it warm up to 123 C.
Ground of course, is still 5 C.
Get in vehicle and go to 7 am. Sun now 15 degree above horizon.
Now ideal black mater on table is about temperature of ground or colder.
It getting energy just not enough to warm it up much.
Then go to 6 am. Or go back to spot where sun’s disk is fully above horizon.
Now stuff on table really cold. But tilt the table to facing the sun and it’s 123 C.
So threw flour on this ground surface it would fairly bright, but surface does get much
of any of sun’s energy. But of course, it’s 5 C.
And same applies if go east. As does going north and south.
So Sun is lighting these entire hemisphere but unequally heating the entire hemisphere.
And of course night side is never lit.
So this why a black surface at noon is not 123 C, but instead is 5 C. You have small percentage of sphere being heated,
Now, to the point.
Suppose instead covering entire sphere with ideal blackbody material. You do the tropics.
Or 2 hours drive north or south from equator. So you from 9 am to 3 pm- both west to east and north to south. In square you getting more of less full energy of sun on every square meter.
Though exact corners it might diminish a bit,
So length at equator of 6 hours is still 1/4 of circumference. Or 1/2 of 12 hours day. Or 1/4 of 24 hours. But on either end of 6 hour area of full sun, I have hour period where getting the table top at about 50 C, and next hour is about 5 C. We could the other 6 hours of sunlight keep that group warm. And full slight square heats 12 hours of permanent night.
So instead of 1/4, I divide by 1/3.
So roughly this gives half world at about 15 C. Other half some region at near absolute freezing
and parts of sunlit size which above 2 hour mark north south which if sand would as hot as 120 C and which diminish well below freezing as go poleward.
Now to this we add Mars like atmosphere. So add 40 to 50 trillion tonnes of Nitrogen.
Such thin atmosphere will have little affect upon amount sunlight reaching the ideal blackbody material, nor will the relative cool surface warm the gas much, but areas above the 2 hour mark will heat the gas quite a bit. And this warmed gas would easily raise the area which are at absolute freezing at by at least 100 K. Or we assume that no nitrogen freezes out anywhere on the surface.
With this tiny atmosphere, which because it 1 gee world would not be the large atmosphere
height of Mars, but still very much be a vacuum or nothing human breath in without a pressure or space suit. With this tiny atmosphere, sunlight bend a bit over the horizon.
So morning 6 am and dawn 6 pm would get a tiny bit more direct sunlight reaching the surface.
So, somewhere around say 10 K of warming.
With such atmosphere there is going to be wind, so avoid dust, cover all area which don’t ideal blackbody material with pebbles larger than a pea. Therefore should not get dust, nor dunes.
Now, what kind of weather do we get.
So on sunlit side above and below the 2 hour away from equator, we vast but somewhat narrow desert which has a blazing hot surface, but with practically non-existent atmosphere.
So I think would similar to Mars. On Mars the warmed surface air stays near the surface.
So you might air the in the first foot being 100 C, and lower by 10 or 20 C every foot in elevation. In other words an inversion layer. but I think it would trap atmospheric gases and
could be complicated.
Let up the atmosphere to 1/3 of earth atmosphere. With this much atmosphere despite having no water, it seems to me one would get something resembling Earth troposphere.
And returning to warm area, one gets convection of air. One could still heat inversions, but it seems the warmed air would go to much higher height
And it seems we talk about average air temperature rather than surface skin temperature.
So half world’s air temperature would be 15 C or warmer [“tropical band” at equator”.
On sunlit side between 30 and 45 degrees latitude, we would have very hot desert. Just above
30 degree being hottest and cooling to 50 C at 45 degree latitude.
With increased amount atmosphere the hotter regions tend transfer their heat more laterally,
so the warmer air seep into the “tropics” and tend go poleward by some degree. So though the air could cool the night side tropics it also seem day side tropics would warmed somewhat by warmer air. So it seems probably coldest air temperature could somewhere around 200 K.
So what’s 200 K fairly dense air look like. Well, 200 k is -73 C, so resembles high elevation Antarctic air during winter.
Now this sphere is spinning very slowly. So it does about 40,000 km a year, or 109.59 km a day
or 4.5 kph [2.8 mph- at the equator]. Does not seem like much. So seems one will get large north and south pools of cold air on night side.
If one large pools of hots averaging about 75 and as large pools of large cold air at about -75 C. So 1/2 world at 15 and other averaged half at 0 C. So maybe 7.5 instead of 5 C.
It’s unlikely it could much cooler than 5 C. Due most sunlight is being absorbed by ideal blackbody. So unless supposes a blackbody will significantly loses the energy it would gain from sunlight with merely due to 1/3 of Earth atmosphere.
So assuming the average global temperature is 5 C, what happen if rotate this sphere?
Well it has zero affect in regard to ideal blackbody along the tropical band.
But it going warm the cold regions and cool the warm regions.
So if rotation is like earth, how much would the hot regions cool during the nite?
Let try something. Say having instantaneous change. So second it’s under blazing sun and next second it’s darkness. And one second in in darkness and next second it’s in blazing sunlight. So how fast does the hot cool and how fast does cold warm.
So actually have clue about this due to LRO’s diviner instrument, which recorded Lunar surface during an eclipse:
http://www.diviner.ucla.edu/blog/?p=610
Which a surface cooling and warming by about 100 K in about 2 hours.
So roughly surface could warm or cool quick though cooling and warming the air could require more time.
So far, we appear to be not getting warmer than global 5 C average.
But I would say it appears this way because we ignore that air would take longer to cool and warm than surface.
We seem to accept that greenhouse is trapping heat, and what what can be replaced by word “trap” is delay. What greenhouse gas are suppose to do is delay cooling. Rather increase heat the skin surface temperature. We don’t measure the skin surface temperature, instead we measure the air temperature to determine average temperature.
So rather than does surface warm quicker or cool quicker, we ask does the air warm quickier.
So if air warms quicker and surface warms and cooler at about same rate, does this increase
air temperature?
Or if average surface surface temperature remains constant, and the air warms faster than it cools, does this increase the average air temperature?
And if true, then does a higher air temperature cause a higher surface temperature [or even care because we aren’t even measuring surface skin temperature]?
So it seems to me, that since there is gravity the air would warm faster than it cools- or heat energy is stored and accumulates in the atmosphere.
Now, I think far more energy is stored in Earth oceans than in Earth’s sky. And so I would say the ocean is major “greenhouse effect”. Or Earth’s ocean is why average temperature would increase by more than 5 C.
But earth ocean is also why Earth average temperature can not rise much higher- Earth can not be like Venus. And if ocean warms, world become more tropical than one could say become “hotter”. Or one gets less of Earth surface area where it freezes at night.
Mario Lento says:
December 28, 2013 at 6:47 pm
Leif: I need to ask the following. Is pressure what now causes the sun to be hot? The answer is no, I think. The pressure was a temporary thing that happened as you say when the contracting cloud of gas occurred presumably due to gravity. Once the pressure is stabilized, the heat energy is no longer concentrated
But the heat is still present and won’t leak away for billions of years. If you turned off the fusion, the contraction will resume. The thing with the pressure is that it is a measure of the number of atoms in the atmosphere. Unless the atmosphere is perfectly transparent [which no atmosphere is] the overlying atoms will prevent some of the energy from escaping to space so the atmosphere at the surface will be warmer.
Leif said:
“Unless the atmosphere is perfectly transparent [which no atmosphere is] the overlying atoms will prevent some of the energy from escaping to space so the atmosphere at the surface will be warmer.”
Just so, and if he atmosphere is radiatively inert then conduction of energy between surface and air plus convective overturning will do the job. Furthermore, in reality one can never suppress convective overturning to produce an isothermal atmosphere.
gbaike said:
“We seem to accept that greenhouse is trapping heat, and what can be replaced by word “trap” is delay.”
Just so.
Conduction plus convective overturning takes time so there we have a gravity and mass induced delay without involving radiation directly.
The length of delay being related to the entire atmospheric mass the effect is magnitudes greater than any effect from radiative characteristics, Furthermore, changes in atmospheric radiative characteristics are partly or wholly offset by atmospheric expansion which reduces mass density at the surface which is a cooling effect since it reduces conduction.
Willis’s thermostat mechanism is simply the variable interplay between conduction and radiation as both work against one another by varying air parcel densities and consequent speeds of uplift and descent in order to maintain top of atmosphere radiative balance. Water vapour is just along for the ride but provides a useful ‘lubricant’ for the working fluid of air.
gbaike said:
“Now, I think far more energy is stored in Earth oceans than in Earth’s sky. And so I would say the ocean is major “greenhouse effect”.”
Just so.
See my “Hot Water Bottle Effect.”
Jurgen said:
“The “pressure heads” are confusing pressure (static) with compression (dynamic process with energy transfer).”
Nearly right.
In fact it is the warmists who are confusing those like me who point out the dynamic heat transfers involved in conduction and convective overturning with those who say or imply that pressure alone changes temperature. What changes temperature is work done against gravity during convective uplift (cooling) and work done with gravity on convective descent (warming).
The associated delay in the transmission of solar energy through the system warms the surface above S-B and lifts the height at which S-B is satisfied off the ground.
In a radiatively inert atmosphere convective overturning works to return kinetic energy back to the surface (which is then the effective radiating level) for radiation to space at the right speed to maintain system balance.
In a radiatively active atmosphere the effective radiating level also lifts off the surface towards the S-B height so that convective overturning has less work to do in returning kinetic energy to the effective radiating level.for radiation to space.
That last point is why I say that GHGs like water vapour and also the various non condensing GHGs such as CO2 act as a system lubricant in the troposphere.
Ozone in the stratosphere is a slightly different scenario because ozone interacts directly with solar shortwave radiation.
Stephen Wilde says:
December 28, 2013 at 1:18 am (Edit)
Thanks, Stephen. It’s so much easier when I know what you are referring to. So let me start by giving a fuller quote, so we have a bit of context:
Now, in this situation there is no variation in the surface temperature, because the planet is evenly heated. As a result, there is no “‘surplus’ energy constantly recycling conductively between the surface and the mass of the atmosphere” as you suppose.
Please follow the logic in the quote above, and you’ll see why adding a transparent GHG-free atmosphere to the planet in the thought experiment does not, and can not, exceed the S-B temperature no matter what the mechanism might be. If it could raise the temperature even one degree, the surface would be radiating on a continuous basis more than it is receiving … which is impossible.
All the best,
w.
Willis 9:36 …”a transparent GHG-free atmosphere…”
Transparent which cannot exist in nature because all mass >0K emits IR. So by your reverse logic method adding any natural atmosphere to a planet increases surface Tmean over vacuum S-B. Same concept as lsvalgaard writes 7:37pm.
Trick says:
December 28, 2013 at 9:57 pm (Edit)
This claim, that everything emits and absorbs IR, is widely believed but is absolutely untrue. Monatomic gases such as argon neither emit nor absorb thermal IR.
w.
Willis 10:07pm: That would change many things. In particular experimentalists could then obtain 0.0K but they cannot as yet. Cite for your assertion?
Willis Eschenbach says:
December 28, 2013 at 10:07 pm
Monatomic gases such as argon neither emit nor absorb thermal IR.
But they emit and absorb other wavelengths so if the temperature of your planet is high enough [some thousand degrees] they will emit and absorb. Here you can see the colors of some of the spectral lines they emit and absorb: http://www.leif.org/research/Helium.pdf
Thanks, Leif. You are correct that argon will absorb and emit visible light at very high temperatures, as your link shows. However, for earth-like temperatures, they neither absorb nor emit IR.
w.