Bob Wentworth Ph.D. (Applied Physics)
[Corrigendum 4/27: The analysis in this essay is flawed. For a corrected analysis, please see
Trouble in Noonworld, Take 2.]
After I offered “Deconstructing Wilde and Mulholland’s Analysis of Earth’s Energy Budget,” I realized I had focused on a paper by Stephen Wilde and Philip Mulholland that was less than ideal for addressing the heart of their work. So, today, I’d like to examine Mulholland & Wilde’s “Modelling the Climate of Noonworld: A New Look at Venus.”
I very much enjoyed the setup of the situation Mulholland & Wilde (M&W) chose to examine. They chose to examine the thermal behavior of a hypothetical tidally-locked (same side always faces the Sun) planet with an atmosphere transparent to all wavelengths of radiation.
Here is the figure M&W use to illustrate the energy flows on the planet they call “Noonworld.”
Sunlight warms the Lit hemisphere. The planetary surface radiates some of the absorbed energy flux into space, unhindered by the transparent atmosphere. The remainder of the absorbed insolation energy flux is conducted into the atmosphere. The warm air rises, then flows to the Dark hemisphere, where the air sinks to the cold surface, warms it, then circulates back to the Lit hemisphere. The dark hemisphere radiates its absorbed energy flux into space, again unhindered by the atmosphere.
The convective circulation is described as being much like a Hadley Cell on Earth.
Sounds good, so far, right?
Not so fast.
You see, natural convection is a process that occurs in a fluid in a gravitational field when there is a heat source, a heat sink, and a “thermal head.” What is a “thermal head”? It’s a pressure differential that is created because the heat sink is elevated above the heat source. It’s that pressure differential that drives the circulation process. No thermal head, no circulation.
On Noonworld, the heat sink (the planetary surface on the Dark side) is at the same elevation as the heat source (the surface on the Lit side). There is no thermal head. There will be no convection.
But surely Noonworld is just like Earth in that respect, isn’t it? On Earth, convective circulation cells form by hot air rising over a warm region and then sinking over a cold region, and the hot and cold regions are all at the same elevation, right?
Yes, but that description leaves out a key difference between Earth and Noonworld.
Earth has greenhouse gases which radiate and cool the atmosphere, providing an elevated heat sink. That is what provides the thermal head that drives convective cells on Earth.
Noonworld doesn’t have greenhouse gases to provide an elevated heat sink. There are not going to be any convective cells forming to circulate gases between the hemispheres.
Oops.
Yet, it wouldn’t be very satisfying to end the story right there. So, to allow the story to continue, let’s stipulate that convective cells magically circulate atmosphere between the hemispheres despite the lack of any pressure differential to drive the process.
Corrigendum 4/21: The “Oops” needs to be for my error. Natural convection will, in fact, occur on Noonworld. Since writing this, I’ve realized that a “thermal head” is required for natural convection to occur in a closed loop of fluid, but it is not required in an open container of fluid, such as an atmosphere. The difference arises because in a closed loop of fluid the upper and lower circulatory flows are thermally isolated from one another, while in an open container the upper and lower circulatory flows are in thermal contact with one another. This leads to different dynamics.
* * *
M&W set out to examine how energy flows through the system and establishes equilibrium temperatures. To do this, they make an assumption that there is a fixed “Diabatic Energy Partition Ratio,” which I will denote 𝛾, between the surface and the atmosphere.
What this means is that each time an energy flux, P, arrives at the interface between the surface and the atmosphere, the energy flux is assumed to “partition” itself so that the atmosphere receives energy flux 𝛾P and the surface receives, and is assumed to radiate, energy flux (1-𝛾)P.
One oddity of this assumption is that where the energy flux ends up does not depend on where it starts. In other words, if 𝛾=0.2, then it is assumed that any flux present will partition into 20% being in the air and 80% going into the surface and being radiated. So, that means that if insolation is absorbed into the surface, 20% of that flux will be transferred to the air; yet if a flux starts out in the air, then 80% of it will apparently be transferred to the surface. I would think that if conduction between the surface and the air was weak, then energy flux would tend to stay where it started out. Yet, that’s not the way energy fluxes are assumed to behave. The assumption that energy fluxes have a preference for being in air or being in the surface (or dividing evenly) seems not at all justifiable.
That’s concerning, but let’s continue.
For Noonworld, M&W assume 𝛾=1/2 on both the Lit and Dark hemispheres. Later, when modeling Venus, they use a value for the Lit side 𝛾ₗ which is distinct from the value 𝛾ₒ used for the Dark side.
So, how does this play out?
The summary is that, starting from the solar irradiation flux, the energy fluxes get partitioned, circulate with the atmosphere, get partitioned again, and this repeats indefinitely. This creates infinite series of terms which can be added up to compute the radiant flux of thermal radiation on the Lit side and the Dark side, respectively. From these radiant fluxes, one can calculate the temperature of each side.
* * *
Here are the mathematical details, in case you want them, but feel free to skip this segment.
Given a Solar constant, S (watts/m²), the average isolation energy flux on the Lit hemisphere is S/2.
This initial energy flux gets partitioned and circulates, again and again:
- The absorbed insolation S/2 is taken to lead to the Lit side radiating an energy flux Rₗ ₀ = (1- 𝛾ₗ) S/2, while the atmosphere receives an energy flux Aₗ ₀ = 𝛾ₗ S/2.
- The warmed air travels to the Dark side, where its energy flux is partitioned, leading to the surface radiating Rₒ ₀ = (1-𝛾ₒ) 𝛾ₗ S/2 and the atmosphere retains Aₒ ₀ = 𝛾ₒ 𝛾ₗ S/2.
- The now cold air travels to the Lit side, where its energy flux is partitioned, leading to the surface radiating an additional amount Rₗ ₁ = (1- 𝛾ₗ ) 𝛾ₒ 𝛾ₗ S/2 and the atmosphere retaining an additional amount Aₗ ₁ = 𝛾ₒ 𝛾ₗ² S/2.
As the energy fluxes circulate back and forth, they get partitioned again and again, adding additional terms to the amount radiated and in the atmosphere.
The incremental additions to these energy fluxes form geometric series, making it easy to add up the infinite series. The resulting thermal radiation fluxes are:
𝜀σTₗ⁴ = Rₗ = (1- 𝛾ₗ ) (S/2)/(1- 𝛾ₒ 𝛾ₗ)
𝜀σTₒ⁴ = Rₒ = (1-𝛾ₒ) 𝛾ₗ (S/2)/(1- 𝛾ₒ 𝛾ₗ)
where Tₗ and Tₒ are the temperatures of the Lit side and Dark side, respectively.
For Noonworld, one finds Rₗ = (2/3) S/2 and Rₒ = (1/3) S/2.
* * *
The end result is that M&W have a recipe for finding the temperatures of the Lit side and the Dark side as a function of the “Diabatic Energy Partition Ratio” 𝛾 on each side of the planet.
Given the temperatures of the two sides of the planet, one can solve for the two partition ratios. M&W use an iterative Inverse Modelling process to numerically solve for the partition ratios that correspond to temperatures on Venus.
Is it surprising that M&W are able to find parameters that fit the temperatures on Venus?
Not really. Their model led to a fairly general function mapping two partitioning parameters to two temperature parameters. Fitting this model to data is simply a curve fitting process involving two tunable parameters and two data points to be fit. When a fit is achieved this isn’t surprising and doesn’t have any inherent significance.
Yet, could M&W have captured some real physics, demonstrating that convection can account for planetary temperatures?
No.
Unfortunately, the energy partitioning rule M&W used to calculate their results is completely non-physical. Heat transport can’t work that way.
M&W are treating convection as if it behaves somewhat like radiant flux, with the heat flux carried by convection being able to be split, almost as if by partially reflective mirrors.
Convection is a means of carrying a heat flux. Heat fluxes flow from hot to cold. Unlike radiation, they can’t ever recycle, building up power like radiation in a resonant cavity.
If one looks careful at step #3 in the process described above, it involves cold air circulating to the hot side of the planet and then giving some of its heat to the hot surface. It involves heat flowing from cold to hot, violating the Second Law of Thermodynamics.
* * *
Air can circulate around and around in a cycle, but a heat flux can’t.
Convecting air can carry a heat flux, but that heat flux is not constrained to stay with the air. The heat flux will only travel from hot to cold. If the air circulates back to a hotter place, the heat flux will not go with it.
So, on Noonworld, the Dark side partitioning ratio is always 𝛾ₒ = 0. The entire convective heat flux from the warm air always flows into the cold surface.
Any other outcome violates the Second Law of Thermodynamics.
Corrigendum 4/21: Another “Oops” on my part is needed here. While I remain convinced that M&W’s model is inconsistent with thermodynamic principles, my explanation here of the nature of the problem is wrong. One can analyze a problem from an “energy flow” perspective or a “heat flow” perspective. I incorrectly applied a “heat flow” perspective to an “energy flow” diagram. So, for the moment, the “trouble in Noonworld” is my own. Apologies to all.
As far as I can tell, this leaves M&W’s analytic approach nowhere to go. I don’t see how it could be salvaged.
While I’ve enjoyed learning and thinking about M&W’s energy partitioning convection model, it has nothing to do with the way actual convective heat transfer works.
Nor does it correspond to how temperatures on planets get determined.
* * *
I feel quite sad to relay this news to Philip Mulholland and Stephen Wilde, who I imagine have given enormous attention, thought, and heart to developing this model and sorting through its implications.
I don’t know how it is for them, but for me, my creations sometimes seem like a part of me. It would be a significant loss, if I learned that something that I had invested deeply in creating wasn’t what I had hoped it was.
I trust that Philip, Stephen, and I share a common desire to understand reality as it is. I hope this essay supports that.
Corrigendum 4/21: The preceding conclusions of mine are no longer justified on the basis of the contents of this essay.
You have missed a very important point namely that as air rises KE converts to PE as a result of expansion as per the Gas Laws.
That is what causes the decreasing temperature gradient with height, not radiative gases leaking energy to space.
Such leakage of energy to space is constrained by the colder temperatures at height and so does not add any additional cooling to the expansion process.
Thus there is an elevated heat sink even without radiative gases and your exposition fails at the first hurdle.
The next problem is that you are introducing radiative fluxes again which is unnecessary.
The whole process is simply conversion of KE to PE in rising air and PE to KE in falling air. Radiative fluxes are a consequence of those conversions.
The is no flow from cold to hot, just conversion of PE to KE as the air descends thus no breach of the Laws of Thermodynamics.
I think that if you are genuinely interested the best approach would probably be via private correspondence rather than in public.
Up-voted back to 0 just because it’s rude to down vote someone directly involved without leaving an explanatory comment.
But I did.
Voted back up, because it closer to the TRUTH than most other explanations.
Bob definitely has a “radiation” fetish, whereas it is bulk air movements caused by temperature and pressure difference that control the movement of energy in the atmosphere.
You got a down vote because of your last paragraph.
This gets many minds looking at the problem and is what science is about. I think the trouble today is that too much science is being done in a closed shop where conflicting ideas don’t get aired properly.
He made it quite clear that he wasn’t trying to belittle your effort.
Fair enough.
Ok.
I also disagree with the curve fitting suggestion. When applying our model to observed parameters it then throws up predicted numbers that are very close to other observations.
Predictive ability is a valuable feature.
If you do not mind me asking;
How does your model compare with the GCM(s)?
cheers
The GCMs attribute the surface temperature enhancement above that predicted by the S-B equation to radiative gases.
We attribute it to convective overturning within the mass of an atmosphere constrained by gravity.
We are finding that our model is much more versatile in providing an explanation for the observed atmospheric features which taken together constitute climate.
But, excuse my simpleton point;
but still for best or worse,
at least GCMs do model the thermal circulation by the main mean of currents, where either the thermal fluxes, radiation flux or CO2 fux are
“slave drivers” and not “master drivers” of thermal circulation.
And if I am not wrong, the main potential and force of “thermal head” in
consideration of the thermal current transfere,
consists as “horizontal”,
going in “round” currents
circulation in Tropics and
from Tropics to polar regions, through the oceans and atmosphere.
There is a proper meaningful difference between the concept and the meaning of “current” versus “flux”,
init!
cheers
Yes the GCMs aren’t too bad on the circulation aspect but they rely on the GHG hypothesis to get started together with the existing climate zones created under our convective hypothesis. Radiative theory says nothing about the distribution of permanent climate zones.
The surface temperature enhancement is the same with both the radiative and convective hypotheses so they both start out at the measured surface temperature and go from there.
The GCMs also make use of the US Standard Atmosphere which is used in rocketry and flight and interestingly doesn’t involve any consideration of radiative physics.
Since their understanding of the cause of the surface temperature is incorrect they do not realise that a change in radiative gases will only cause an indiscernible adjustment in the climate zones instead of a change in surface temperature.
I do respect and appreciate your work and effort towards a better understanding of the world we live in…
I really do.
But still testing and criticising is a part of that “fiery game”.
Still the main point of GCM modelling, as far as I can tell,
happens to be the aim of an “experiment”, where the best possible modelling of a system is produced in proposition of fluid thermodynamics and all the thermal “currenty” things there modeled at the best possible conformity to reality, with the main aim of getting a better understanding of radiative physics, fluxes and the effects of such as.
The main problem there
stands with the corruption of modelers and the climastrolog “scientistas” which keep misinterpreting intentionally and knowingly the purpose and the results of GCM(s).
Please do realise, I do very much appreciate work like you and your friend do…
and also the work of those who do challenge, critique and point out the flaws and contradictions
found there.
You see, I never can do or produce something like you can.
Appreciated a lot.
Regardless.
cheers
whiten,
You should not belittle yourself, we are all just sitting in Plato’s Cave watching the shadows.
What is the elevated heat sink?
I was using Bob’s terminology. He is referring to the decline in temperature with height that allows convection to develop. In effect, the process of thermal KE disappearing into non-thermal PE with height can be regarded as a heat sink.
That’s not a sink. The surface is the only sink in your model. The atmosphere will cool from the bottom, be stable. How then can there be convection.
There will be a decline in temperature with height along the lapse rate slope. That cannot be avoided.
On receipt of incoming solar energy there will be temperature and density differentials in the horizontal plane at the surface so convection must ensue even without radiative gases.
All outgoing radiation will go to space from the surface, that much is true, but convection continues in parallel so surface energy is also going into that.
Space is a sink for radiation
The atmosphere is a sink for conduction and convection.
Thus, to meet both energy requirements there must be a surface temperature enhancement even without the presence of radiative gases.
There is a lapse rate, convection or no convection, in this case the gravitational or dry adiabatic lapse rate. But because the atmosphere is cooled at the bottom the lapse rate is less than the gravitational lapse rate, i.e. no convection.
That is an inversion which is a short term localised event. In general the lapse rate slope does decline with height and convection is inevitable without greenhouse gases.
No, that’s the state of your system at equilibrium.
“When the lapse rate is less than the adiabatic lapse rate the atmosphere is stable and convection will not occur.”
https://en.wikipedia.org/wiki/Lapse_rate
No, that is a localised short term phenomenon. The link is referring to the atmosphere at a given location not the entire global atmosphere. No planet arrives at an overall average lapse rate slope less or more than the adiabatic lapse rate slope set by atmospheric mass and the strength of the gravity field.
If it did then in both cases the atmosphere would be lost due to a failure to preserve hydrostatic equilibrium.
What will make the air at ToA descending when there is nothing cooling it?
(and it’s the specific heat, not mass, setting the lapse rate)
Forced convection in meteorology. I go into more detail for another commenter below.
The specific heat of a given molecule of a given mass will determine the height at which it settles along the lapse rate slope.
The lapse rate is set by mass and gravity because gravity creates an exponential decline in density and pressure with height. In 3D geometry an exponential decline will produce a linear slope.
“The descent is aided by the fact that the higher air has become so cold that it starts off slightly denser and thus heavier than the slightly warmer air beneath”
I’m afraid that’s more nonsense. This cooling will only happen with the presence of radiative gases. In this case the air will only cool down to the same temperature as the surrounding.
(it’s still specific heat, not mass, see my wikilink, but it’s not important here)
So you say that rising air doesn’t cool unless GHGs are present ?
No, I’m saying it will never get colder than the surrounding air.
You really need to consider this since “no planet arrives” does not apply in your hypothetical case. I like your idea of a simple model to start digging in to convection on planets. However the heat sink in the atmosphere on our planet is clouds, which have massive surface area and radiate to space. This reduces local entropy. Your model does not have a heat sink in the atmosphere since the gases are transparent.
Clouds affect albedo which mimics a reduction in insolation so that gives a net cooling effect by reducing energy able to enter the system in the first place.
All their other effects such as you mention do try to destabilise the system but convective adjustments neutralise them for the system as a whole.
What do you mean the atmosphere is cooled on the bottom? In this model that only takes place on the night side of the planet and the atmosphere is warmed from the bottom on the day side. On Earth, that happens every night and a literal temperature inversion occurs on calm and cloudless nights at the surface boundary layer.
There is no radiative gases so all energy transport must go via the surface. Both heating and cooling.
How much convection is taking place in a temperature inversion?
You realize there is conduction between the atmosphere and surface and within the atmosphere itself, right?
None, that’s how a night time temperature inversion forms. And then it rapidly goes away as the sun rises, the surface is heated, and convection once again takes place due to conduction at the boundary layer between the atmosphere and solar heated surface.
All energy into and out of the atmosphere goes via the surface. What’s the problem?
Bob writes:
“They chose to examine the thermal behavior of a hypothetical tidally-locked (same side always faces the Sun) planet with an atmosphere transparent to all wavelengths of radiation.”
There is no sunrise. At least the unlit side is in a permanent inversion. There is no air descending.
An inversion only occurs when there is no wind which causes turbulent mixing of the atmosphere and brings warm air from aloft down to replace the cooler air at the surface.
On Noon World there would be constant wind from the dark side to the light side and that air would be replaced by the air aloft which was originally advected from the warmed air on the light side which was replaced from the surface winds – a convection cycle.
Don’t think so.
https://www.drroyspencer.com/2009/12/what-if-there-was-no-greenhouse-effect/
What happens to the rising air on the lit side ? It has to come down somewhere else.
Sorry, Steve, but it is density (not temperature) that is key to convection. Since the mass is also dropping as you rise the overall density is not changing. Hence, no convection even though the surface is warmer.
The decline in density leads to the decline in temperature due to expansion. That is implicit. Your second sentence makes no sense.
There MUST be more “embodied” energy lower in the atmosphere than higher up, because the lower atmosphere has to support more gravity based air mass.
The embodied energy is expressed as kinetic energy which expresses as temperature.
Interestingly, it follows from the basic physics that every molecule in an atmosphere contains the same amount of energy but at the bottom it is all KE and at the top it is all PE apart from a bit of KE needed to match the temperature of space.
KE plus PE is a constant for a given planet.
The lapse rate defines the change from KE to PE as one goes higher and any molecule that doesn’t fit will rise or fall until it does.
Convection is always working to align every molecule in the atmosphere with its ‘correct’ position along the lapse rate slope.
Although the Earth has several different lapse rate slopes between surface and space the net gradient of all those slopes will match that determined by mass and gravity.
.
H2O can disrupt this.
CO2 CANNOT !!
Hence, CO2 CANNOT cause warming
That would be true only if temperature profile for the entire atmosphere followed the adiabatic lapse rate.
It doesn’t. So, I’m puzzled by your claim.
It does on average for the globe as a whole but never does in any single location except perhaps momentarily. The atmosphere is very volatile.
You’re asserting that the entire atmosphere on average has a temperature profile that follows the adiabatic lapse rathe? Is that the claim?
Are you including the stratosphere in the “whole atmosphere”?
Even the troposphere does not “on average” follow the adiabatic lapse rate. To varying degrees in various places it follow a moist lapse rate, which has temperature change slower with altitude than the adiabatic lapse rate.
The lapse rate is never faster than the adiabatic rate and usually less fast. This makes it mathematically impossible that the average could be the adiabatic lapse rate.
Have you looked at charts of atmospheric temperature profiles? The adiabatic lapse rate involves faster temperature changes than anything on the charts of the average atmospheric profile.
Is this something that, on theoretical grounds, you believe should be true?
If you look at the lapse rate profile from surface to space you will see the shape of a W set on its side.
Compositional variations on the way up lead to that shape, If one ignores the distortions the average slope matches the adiabatic rate of 9.8. The US Standard Atmosphere used in flight and rocketry relies on that.
As for the troposphere the moist rate is indeed less than 9.8 but when the moisture has been stripped out by condensation and rainfall the descent rate returns to 9.8. The difference is negated by radiation to space from the condensate so the average remains at 9.8.
If the atmosphere were not to average out at 9.8 then hydrostatic equilibrium would be destroyed and the atmosphere would either be lost to space or would fall to the ground.
The adiabatic lapse rate is 9.8℃/km. The International Standard Atmosphere sets the environmental lapse rate at 6.49℃/km in the troposphere. In every part of the atmosphere above the troposphere, the atmosphere has a lapse rate less than that 6.49℃/km.
There is elevation at which the lapse rate is (on average) as large as the environmental lapse rate.
You are repeatedly making a claim that is wildly inconsistent with reality.
Please take a plot of atmospheric temperature vs. altitude, and draw a line on it from the origin at a slope of 9.8℃/km. You will see that it is not the average slope, and does not even intersect the actual temperature profile.
I beg you to do this.
You have badly misunderstood how hydrostatic equilibrium works if you believe this to be true.
Absolutely any profile of temperature vs. altitude is consistent with hydrostatic equilibrium.
If any parts of the temperature profile have a lapse rate greater than the adiabatic lapse rate, then that part of the atmosphere will be dynamically unstable and will adjust itself to have a less extreme lapse rate. But, portions of the atmosphere with lapse rates closer to isothermal than the adiabatic lapse rate are entirely stable—no adjustment is needed, and the atmosphere will not automatically change the lapse rate to make it closer to the adiabatic rate.
How do you know it doesn’t on average from surface to space and around the world ?
See above comment.
Alternatively, look at the plot of “potential temperature” in this post. Your hypothesis is equivalent to saying that “potential temperature” is, on average, constant as a function of altitude. The figure clearly indicates that this not NOT the case, not even in the troposphere. Potential temperature clearly increases with altitude, at every single latitude, and averaged across all latitudes.
It would be difficult for your assertion to be more inconsistent with reality.
That potential temperature plot only seems to go up to 0.25bar or so, well within the troposphere. I’m pretty sure Mr Wilde is referring to the full atmospheric profile. Regardless, potential temperature concept is simply air temp normalized to 1 bar so it averages out over the full profile up to 0 bar. I don’t see how the plot has any relevance.
For higher up in the atmosphere, revert to the method of analysis I suggested in this comment. I’m not aware of any plots of temperature vs. altitude that are remotely consistent with Stephen’s hypothesis.
The troposphere is where Stephen’s hypothesis is closest to being true. (It’s not very close.) Considering the rest of the atmosphere does not help his case.
“Potential temperature” is defined as the temperature an air parcel would have if brought back to 1 bar at the adiabatic lapse rate. So, if the atmosphere were following the adiabatic lapse rate, potential temperature would not vary at all with altitude. Checking for such constancy is a simple way of checking Stephen’s hypothesis for the part of the atmosphere where such data is available.
My reference to the standard atmosphere appears to have been misplaced but it only goes up to 36000 feet.
An average has to be taken from the surface to the boundary of space and for an atmosphere to be retained that average must match the rate of density decline set by mass and gravity which for Earth requires the dry adiabatic rate of 9.8.
There are infinite variations allowed on the way up and from place to place and Bob mentions some of them but they must all average out to that number for an atmosphere to remain in hydrostatic equilibrium.
One point I have not been able to verify is whether 9.8 is actually required to match the density gradient set by mass and gravity.
I have to accept that it might be yet another number but the principle remains the same.
If the actual decline in temperatures whatever it may be from surface to space does not match the rate at which density declines with height (on average) then hydrostatic equilibrium cannot be maintained.
Yes, there is a relationship between temperature, density, and pressure in the atmosphere, and the way that vary with altitude.
However, you have this completely backwards.
Density and pressure and temperature always automatically adjust to restore equilibrium. And this equilibrium does not require that things match the adiabatic lapse rate or anything like it.
The reason it is called an “equilibrium” is because there are restoring forces that always return the system to a state of hydrostatic equilibrium whenever the something tries to take the system out of equilibrium.
The adiabatic lapse rate is -9.8℃/km.
The International Standard Atmosphere includes segments with these lapse rates, in ascending order: -6.5, 0, +1.0, +2.8, 0.0, -2.8, -2.0 ℃/km.
No matter what weights you give as you average those segments, it cannot possibly average to -9.8 !!!!!!!!
Would you please track down wherever you think you heard this information from?
It’s completely wrong. You are misremembering something or misunderstood it in the first place.
You concede that a persistent equilibrium exists and that one requires adjustments to maintain it. Good.
The way that density, pressure and temperature automatically adjust is via convection. Certainly not radiation. Do you have an alternative?
The speed of convection responds to the steepness of the lapse rate slope.
For equilibrium to exist in the first place there has to be an angle of lapse rate slope that on average matches the decline in density from surface to space.
You have suggested to me that none of the individually observed lapse rate slopes mentioned in the ISA appear to match that decline in density with height and on reflection I am inclined to accept that. It is likely that the dry adiabatic lapse rate in the tropopause does not reflect the required steepness of lapse rate slope to enable equilibrium to be achieved and maintained.
That being the case it will need to be compensated for at other locations in the vertical column between surface and space. That will involve Stratosphere, Mesosphere and Thermosphere so there is plenty of room for the system to play with.
So, to achieve the adjustment process that you accept, how else do you think things work ?
If you accept those adjustments in principle then it logically follows that if radiative gases or anything else seek to alter that equilibrium then those convective adjustments will occur to restore equilibrium which is exactly what our model and its underlying processes achieve.
There is no process within the radiative theory that allows such adjustments to occur. The radiative theory creates an imbalance but has no means of neutralising it.
I really can’t see how you can counter this point.
Yes, I have an alternative.
Convection is a process that persists (for at least a while) and involves a circulation loop.
Density, pressure, and temperature adjust via air packets moving to maintain hydrostatic equilibrium—but the movement can sometimes be transient and need not involve a circulation loop.
Under some circumstances, convection will be the mechanism that restores equilibrium, and under other circumstances it is not.
The important thing about these other mechanisms not being convection is that they do not, in steady state, establish an adiabatic lapse rate.
What is the proof of this? The fact that no part of the atmosphere is observed to follow the adiabatic lapse rate.
When reality doesn’t conform to your ideas, reality needs needs to be what is given priority.
The lapse rates I included addressed the Stratosphere and Mesosphere. And there is so little mass in the Thermosphere that it hardly counts. So, there isn’t much “room for [your hypothesis] to play with.”
Radiation may heat or cool the atmosphere, but “radiative theory” doesn’t need to address how the atmosphere adjusts. The atmosphere adjusts using non-radiative mechanisms.
But, those mechanisms do not conform to how you seem to believe things work.
What is your non convective adjustment process?
All you have suggested is that minor movements within the larger overall circulation are not convection.
That is false. They are all convective adjustments responding to a local distortion of the lapse rate slope set by mass and gravity.
I have always said that the atmosphere adjusts using non radiative energy transfers and in your closing comments you actually agree.
The ISA goes to 36000 feet which does not include the stratosphere mesosphere and thermosphere.
You really have nowhere to go having accepted that stability is maintained by non radiative processes.
Those processes adjust for all imbalances including those introduced by radiative imbalances such as from GHGs.
I’ve just spotted that the ISA does go higher than 36000 feet but that does not help you because I have conceded that I do not know and the ISA does not specify the average slope set by mass and gravity.
My contention is simply that whatever that slope is it exists and it has to be complied with to maintain hydrostatic equilibrium.
The actual number matters not for the purpose of our work.
Convective adjustments always correct distortions of the slope back to the average set by mass and gravity whatever that slope might be.
If temperatures decrease with increasing altitude faster than the lapse rate, convection happens.
If temperature decreases with increasing altitude slower than the lapse rate, convection does not happen. If you don’t get that, then I’m skeptical about whether you actually understand meteorology.
It follows, logically, that there are a wide range of temperature profiles that are hydrostatically stable.
Write me an equation to demonstrate the physics. A principle as strong as the one you’re claiming exists needs to have a solid physical justification backed by math, or there is no reason for it to be a “law.”
I wonder if you’re using vague verbal reasoning, rather than any real math and physics. If so, that way lies madness and nonsense.
It sounds like the bottom line is that you need this principle to be true for your work to be valid.
That’s not the way real science works.
There needs to be a compelling physical justification for a law as powerful as the one you’re asserting. It’s not sufficient that your preconceived ideas won’t work if reality doesn’t conform.
Actually, could you just write out the math for what you assert is true? That would allow us to talk about this much more concretely.
Though, I’ve noticed a striking lack of any equations in your work…
The ISA lapse rates I provided go to 71,802 m.
I have never once implied that the adjustments weren’t non-radiative. That’s not at all what we are disagreeing about.
Imagine that for some bizarre reason a 1000 cubic meter zone of near vacuum opened up in the atmosphere. Things would be out of hydrostatic equilibrium. Air would rush in from all directions to fill the void, and there would be a lot of turbulence until things settled down. Hydrostatic equilibrium would have been restored.
That is not convection.
There are many types of atmospheric adjustments that can happen which are not convection.
“Air would rush in from all directions to fill the void..”
that is exactly what convection is. The term convection includes all components of bulk air movement resulting in the transport of heat and mass. Convection includes all components of advection and diffusive or conductive heat transfer. Advection of heat and mass depends on fluid currents created by broader convective processes. “Air rushing in” suggests a current, specifically, a convective process.
The ongoing blatant arrogance of Mr Wentworth and overt disrespect in this debate makes it difficult to take any of his arguments seriously. He undermines the credibility of his own arguments with a holier-than-thou attitude. He appears blind to his own ignorance and deflects to his comfort zone when required. It is this attitude in academia that stunts any advancement of understanding. As an outside observer I don’t claim to know everything, but I wish to learn. The arguments proposed are unconvincing perhaps, in part, due to the poor communication tactics. .
I regret if my tone got sharper than I would have liked. I got a bit tired and frustrated. It’s important to me to be respectful, so I appreciate your naming that you’re not experiencing that.
I am willing and want to learn, and I am willing to admit mistakes. You’ll see that, in the above blog post, I’ve gotten the editor to amend the text to clearly say where I was wrong.
There are ways of thinking that I deeply trust. Those involve logical rigor, and sometimes, mathematics. That’s what I used to determine that I had been wrong about convection happening on Noonworld, without anyone else needing to convince me.
Mathematics, and what I think of as “logical rigor,” are not in everyone’s comfort zone. They are in mine. I don’t think that makes me “better,” as a human being, than anyone else. Yet, it’s very helpful to me when sorting out technical subjects.
Different people work differently. It’s stupid and unhelpful for me to ask others to think in the way that I do. I regret perhaps having slipped into doing that.
The issue of people being “blind to their own ignorance” is a tricky one. It’s really common for the people on both sides of an argument to believe that the other person is “ignorant.”
How can one tell whose “ignorance” is actually in play?
I think it takes willingness to carefully talk about what we think we know, probing the points where there could be some flaw in our thinking, listening to what the other person says. My goal is to integrate every logically valid point or observation that I hear into a revised way of thinking. I’m willing and wanting to shift and learn.
I get frustrated when the conversation gets stuck in a place of broad assertions being made, without any justification being offered that I can understand.
I’m still working on learning how to navigate this sort of dialog.
I appreciate whatever patience you, or others, are able to extend to me, while I try to figure out how to have these conversations productively and respectfully.
We apparently prefer different nuances to our definition of terms. Fine, we can call it “convection” if that’s your preference.
What is import is what are, or are not, the implications.
Stephen has been arguing that because of adjustments to maintain hydrostatic equilibrium, the atmosphere as a whole is forced toward a temperature profile obeying the adiabatic lapse rate, at least on average.
There are several problems with this argument:
The missing piece for me is to account for the dynamic fluid movement and associated energy transport internally (mostly in the troposphere) while the system as a whole maintains hydrostatic equilibrium.
The average lapse rate to top of atmosphere, in my current frame of understanding, must simply be a result of the average density profile of the atmosphere.
The density axis could be substituted with pressure.
The empirical evidence indicates temperature at the surface to be directly proportional to pressure at the surface. It seems reasonable that convection would dominate and neutralize any radiative effects in the dense troposphere. Fluid motion simply accommodates. The sun is always shining at one time or another to drive this convection.
Above the troposphere, radiative effects seem to take over, such as stratospheric ozone direct solar heating resulting in a positive lapse rate. Things seem to come back to the standard pressure profile out it the mesosphere.
Overall, the proposed hypothesis of adiabatic average temperature profile does not seem to violate current empirical observations. I have yet to see a convincing argument otherwise.
Perhaps you could point me to a comment in this thread, or a passage in the original post, that has the most convincing argument so I can reconsider. This way you won’t have to explain the problem again.
Thanks for offering those charts.
I’ve modified your first chart by adding the adiabatic lapse rate, in blue. The hypothesis of “adiabatic average temperature profile” is a hypothesis that the temperature profile (red curve) on average matches the blue line (adiabatic lapse rate).
Do you believe it is plausible that these two curves could match, on average?
(If I wasn’t successful in attaching the new chart, I’ll try again in a subsequent comment.)
Ok, here is the chart.
Thanks Mr Wentworth. This helps me to see the disconnect. I’ve seen the 9.8 value for the dry adiabatic lapse rate throughout this thread. This has been a misapplication of the lapse rate that applies to the planetary mixed boundary layer. In my study of the boundary layer this value is very useful to understand micro scale climates and energy flux at the surface. The height of the planetary boundary layer varies and depends on many local variables usually described in terms of weather. The planetary boundary layer represents only a small fraction of total atmospheric volume. The misapplication of the boundary layer dry adiabatic lapse rate here does not refute the simple relationship between total atmospheric pressure and average surface temperature to maintain hydrostatic equilibrium for the total system. Introduction of the inverted stratosphere by direct solar absorbing gases results in a total atmospheric column lapse rate magnitude less than that of dry adiabat mixed boundary layer by a factor of roughly 10, and in line with a simple pressure-temperature relationship. The stratosphere acts to significantly stretch out the total volume of the atmosphere.
I’m glad we are making some headway on gaining clarity.
* * *
I’d like to understand what you mean by the “misapplication of the boundary layer dry adiabatic lapse rate.”
First of all, this phrasing is rather confusing because there is only one “dry adiabatic lapse rate.” On Earth, it has a value 𝚪ₐ = 9.8℃/km. This is what the term “dry adiabatic lapse rate” means, regardless of altitude.
There is also a “moist adiabatic lapse rate” 𝚪ᵥᵥ for air saturated with water vapor, which is small in absolute magnitude, but whose value depends on temperature. Typically, it is around 𝚪ᵥᵥ = 5℃/km.
I suppose you are talking about the “boundary layer dry adiabatic lapse rate” because the boundary layer is where the air is most likely to be unsaturated, so that the dry rate applies?
I do see that when I’ve been reading “adiabatic lapse rate” I have been possibly misinterpreting this by translating it to “dry adiabatic lapse rate.” That has likely added to the confusion, insofar as perhaps the “moist adiabatic lapse rate” was intended to be understood?
* * *
Adiabatic air movement will lead to the dry lapse rate until the air saturates, at which point it will follow the moist lapse rate. On average, the “adiabatic lapse rate” must be somewhere in this range.
Taking this into account, the stratosphere can be expected to follow the “adiabatic lapse rate” (though the value of this is not well defined a priori, since it will be a mix of the dry and wet rates).
But, the adiabatic lapse rate will not be followed at higher layers of the atmosphere. Nor will it be honored on average for the atmosphere overall.
I agree with all this. The “total atmospheric column lapse rate magnitude” is presumably also, then, less than the moist adiabatic lapse rate by around a factor of 5 or so?
So, I remain puzzled by your earlier statement “Overall, the proposed hypothesis of adiabatic average temperature profile does not seem to violate current empirical observations.” That would seem to be incompatible with what you’re saying above.
That is the assertion that I am longing to understand.
I remain clueless about what the hypothesis is.
It seemingly can’t be that the overall lapse rate matches the “adiabatic lapse rate”, since that is in a range of about 5-9.8℃/km. The overall lapse rate of the atmosphere seems to be clearly much smaller in magnitude than any version of the adiabatic lapse rate.
What is the “simple pressure-temperature” relationship to lapse rate that is claimed to exist?
I could be more precise. Above the troposphere the average decrease in temperature to the mesopause is in fact subadiabatic in a classical sense. Almost any textbook definition or journal article mentioning lapse rate takes for granted we are working within the troposphere. It seems very far and in between that an author looks at the total lapse rate up to the mesopause. I’m sure there is an appropriate term but I don’t know it. The inverted stratosphere naturally stretches out the distance of the change in temperature from the surface to the mesopause. This results in lower average change per km integrated to the top than if the stratosphere didn’t exist. The classic adiabat of 9.8 does not make any consideration of this because it’s assumed we are working below the tropopause. The vast majority of the atmospheric volume is above the tropopause. Regardless, the surface temperature does not deviate much from a straight line drawn from the mesopause (>0bar) based on pressure or density. Without the stratospheric ozone influences the “total” pressure related temperature increase would be reached over a much shorter distance. This would result in a “total” lapse rate closer to the classic boundary layer adiabat..
Based on the pressure plot above, a total temperature change of roughly 90K is reached over a depth of 100km. This 90K reflects a change from effectively 0 bar to 1bar. In this view, everything in the middle is just noise but the surface and top (endpoints) will respect the pressure slope.profile. In my view, the slope of the endpoints represents the total lapse rate based on an adiabatic process. I concede there could be better terminology.
You can see the inflection point where pressure takes initial effect on most temperature profiles, such as this one from NOAA. The inflection point occurs at 100km at a temperature of roughly -75C. Add one bar of pressure (90K) for a total of +15C. This datum from which pressure has a measurable impact occurs in the lower thermosphere, just above the mesopause.
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It sounds as if you are attributing the increasing temperatures with lower altitudes to the increasing pressure?
If so, I don’t think this is accurate.
In the mesosphere, some information I’ve found suggests the mesosphere gets warmer at lower altitudes primarily because ozone concentrations increase. This increase in ozone is somewhat pressure-related, but it’s an indirect effect, and one that is only relevant in this pressure range; it’s not a pressure effect that occurs lower in the atmosphere.
In the troposphere, the increasing temperature with decreasing altitude is not related to the pressure change. It’s a consequence of the change in gravitational potential in a region where convection dominates. That “change in gravitational potential” might correlate with the pressure change, but you’d see the same slope, even if the overall pressure was doubled or halved.
So, I feel uneasy about describing these regions where it gets warmer as you go lower as being where “pressure has an impact”, as if pressure itself was the cause of these temperature changes.
Maybe what you’re talking about could be called the Surface-Mesopause lapse rate?
Based on the International Standard Atmosphere this involves a temperature change of 105.28℃ over 84.852 km, for a Surface-Mesopause lapse rate of -1.24℃/km.
I suspect the reason for this is that convection shapes the temperature profile in the troposphere to be in accordance with the adiabatic the lapse rate (via some mix of dry and moist adiabatic convection conditions).
However, convection is largely absent in the stratosphere, and uncommon (I think) in the mesosphere. So, the notion of there being any “adiabatic” lapse rate in these portions of the atmosphere is inappropriate. It’s only relevant in parts of the atmosphere when there are strong adiabatically-expanding-or-contracting vertical currents.
There is a “lapse rate” in those parts of the atmosphere, but it’s not determined by adiabatic processes.
Because the processes that determine the lapse rate in different parts of the atmosphere are largely unrelated, there is no obvious mechanism whereby a “total” lapse rate spanning different segments of the atmosphere would be naturally brought to any particular value.
Instead, I’d expect the “total” lapse rate to be a simple mathematical combination of the lapse rates in different sections of the atmosphere, without there being any inherent significance to this “total.”
The “classic adiabat of 9.8” and the moist adiabatic rate of around 5 don’t take any consideration of what happens above the troposphere because the idea of an “adiabatic lapse rate” is a theory of what happens in regions of the atmosphere where convection dominates. That’s not the case above the tropopause.
Yes, although the majority of the mass is below the tropopause.
It sounds like this is where an interesting claim is being made.
If Tₛ is the surface temperature, Tₘ is the mesopause temperature, Aₘ is the mesopause altitude, and -𝚪ₛₘ= -1.24℃/km is the nominal Surface-Mesopause lapse rate, it sounds like you are saying that
Is that what you’re suggesting?
If so, when you say it “doesn’t deviate much”, are you saying this regarding what happens when one considers different locations on the globe? Or different times of day?
Is there some specific evidence that leads you to believe this is true?
Ok, I’m getting that this hypothesis of a fixed Surface-Mesopause lapse rate is tied to a related hypothesis that there is a fixed relationship between pressure and surface temperature? Or something like that?
Is that what this is ultimately about?
“ I’m getting that this hypothesis of a fixed Surface-Mesopause lapse rate is tied to a related hypothesis that there is a fixed relationship between pressure and surface temperature?”
In a nutshell that’s what we can see in the data. I suppose physicists are more qualified than I to develop the relevant hypotheses to describe the processes that make it so. This underlies the discussion here by W&M. They propose a convective mechanism in the troposphere.
Wide variations from the natural slope could arise by different gas compositions. The tropospheric profile is largely influenced by water and its significant mass. The stratosphere by ozone. The troposphere and mesosphere appear to have the greatest adaptive ability to meet the observed temperature boundary condition. The system as observed is bound by lower thermosphere temperature at>0 bar and associated surface temperature at 1 bar. I agree it seems too simple, perhaps, but I have yet to find a credible rebuttal.
I’d love to look at the data that support this. Any pointers to where I might find it?
So, it sounds like there are two key hypotheses in play:
Is that right?
If so, could you say more about why the Mesopause temperature would be considered to be a “boundary condition”? I take it the idea is that constrains temperatures in the lower atmosphere rather than being something that simply arises as a result of the temperatures in the lower atmosphere?
If there really is a fixed Surface-Mesopause lapse rate, that would be interesting. My current understanding of the physics doesn’t suggest any reason why that would be, but maybe closer investigation could reveal something.
* * *
If there is such a fixed Surface-Mesopause lapse rate, I don’t think that it’s likely to be because it’s enforced by “hydrostatic equilibrium”, at least not in the way that Stephen has been talking about the issue.
“Hydrostatic equilibrium” can be achieved for absolutely any atmospheric temperature profile. Though, it will be an unstable equilibrium if the lapse rate is more extreme than the adiabatic lapse rate, i.e., more negative than around -9.8 to -5℃/km.
But, as long as those extreme negative lapse rates are avoided, the atmosphere will happily just sit there with that temperature profile (until the temperature profile changes). I spent earlier today working through equations, demonstrating to myself that for any temperature profile T(z), one can calculate the pressure P(z) or density ρ(z) profile that achieves hydrostatic equilibrium for that temperature profile.
The mere fact of hydrostatic equilibrium does not constrain the possible lapse rate (as long as it’s not more negative than -9.8 to -5℃/km).
The datum arises at >0 bar, whatever altitude that happens to be. The specific altitude will depend on the temperature profile below. In the Earth’s case, this happens to be roughly 100km. This level arises from the cumulative profile of the atmospheric stratification below. The standard atmosphere charts provided above are based on observations. for the sake of this discussion they seem to offer valid data points.
What altitude one refers to as “>0 bar” seems arbitrary. Do you choose the altitude for 0.01 bar? 0.001 bar? 0.0001 bar? 0.00001 bar?
These choices will lead to entirely different altitudes, temperatures, and “total lapse rates”.
That’s not where the pressure reaches “>0 bar”. That’s where there is an inflection point in the temperature profile.
Ok, I can agree with that.
Do you also agree that the temperature here “arises from the cumulative profile of the atmospheric stratification below”?
Sure, I’m happy to go with that.
This doesn’t, however, address the question of what leads you (or others) to believe that (Tₛ – Tₘ) “doesn’t deviate much” from 𝚪ₛₘ⋅Aₘ.
To establish that it “doesn’t deviate” one would need to consider a variety of conditions in which it possibly could deviate, so that one can then observe that it doesn’t.
The inflection point in the temperature profile at a pressure approaching zero offers an observable altitude at which to define the minimum pressure. The principle is not a belief or a hypothesis, it is observed in the system. The standard atmosphere plots offer the average system data. The inflection point lies exactly on the pressure slope to surface temperature..
Bob,
“Maybe what you’re talking about could be called the Surface-Mesopause lapse rate?”
A very interesting discussion.
I have nothing to contribute other than to observe that at times like this it is sometimes necessary to coin a new term.
For example “Gravitational Lapse Rate” to take account of the fact that over a distance of 100 Km gravity is declining and that temperature dependent Cp is also varying.
I’d be more likely to call those gravitational and temperature adjustments to the adiabatic lapse rate than to think of it as a distinct lapse rate.
The change in gravity 100 km up is about a 3% drop. But, so little convection occurs above the tropopause that I’m not sure why one would bother adjusting to get a more precise adiabatic lapse rate for that altitude.
Up to the the tropopause, the variation in gravity is only 0.3%, which is negligible compared to other variable factors.
What little data I can find on how the heat capacity of air varies in the range of temperatures and pressures in the atmospheric suggests that it likely doesn’t vary enough to worry about.
And the Connelly father and on have proven by measurement from 2 million sets of balloon data that the molecular density varies linearly with atmospheric pressure, with H2O being the only atmospheric gas causing any change in that linearity.
The is absolutely no evidence of any CO2 warming, because even if it did occur, it would be canceled immediately by the bulk movement of air controlled by the pressure gradient.
Correct.
The Connellys are on the right track but failed to identify the relevant mechanisms. I think they had to invent some new phenomenon called pervection but that really isn’t necessary.
They invented the word to suit a known phenomenon,
… but its still just BULK AIR MOVEMENT
Convection doesn’t just move a small body of air.
It must move all air above it..
That is a very large energy transfer
It moves all air in the entire circulation cell whether above it or below it. The entire Earth atmosphere is covered by just three cells in reach hemisphere.
Sorry I left out a word in my last sentence. The density gradient is not changing. This is because the mass and temperature gradients are also staying the same. You end up with no force to cause convection.
To create convection you need to exert a force on some parcel of air. Your statement:
“The decline in density leads to the decline in temperature due to expansion”
only happens slowly when the lit side first occurs You still need to overcome the force of gravity. It is the reason the density is greater. With all the components of density remaining the same and gravity remaining the same you have equal forces in every direction.
To create convection within a gravity field you only need temperature and density differentials within the horizontal plane.
The slightest differential will lead to convection. The speed of convection will depend on the size of the differential.
Stephen, I referred to the fountain effect elsewhere. I suspect this is where you are going. Usually, the term advection is used to describe horizontal flow.
I agree that you would get some degree of flow from the highest point of the atmosphere (at the center of the lit side) toward the lowest point in the atmosphere (at the center of the dark side) mainly driven by gravity. Exactly how that worked out would depend on the energy involved.
The problem is you would get no overall warming since these would balance each other.
I don’t think so, at least not in the classical sense. Shooting an arrow into air is the classical exchange of KE/PE via exchange of momentum for work. Here the air is just gradually rising and falling. But it is not the momentum of the air that is lifting it. The process is simply convection. Heat makes gas molecules spread out. Due to buoyancy, the surrounding cooler/denser gas tends to want to migrate under the warmer/lighter gas and push it up to higher altitude. The effect is more analogous to a submarine rising by increasing its bouancy by pumping water out of its ballast tanks. In Noonworld the hotspot is at zenith in the middle so only one cell can form in theory. But in reality chaos can surprise you, as interplanetary exploration has proven again and again.
Yes, but the expansion of gases with height within a gravitational field goes beyond the classical sense where a solid object simply moves up or down. The expansion in addition to lifting creates magnitudes more PE from KE because the process operates in three dimensions. The lifting and expansion both require work against gravity and on descent the same amount of work is done but with gravity for a zero net effect at hydrostatic equilibrium.
I assume the gas expansion (not convection) would be highest at the center of the lit side and you would have a fountain effect. The expansion would spread out into the vacuum that surrounds it. This could happen all the way to the edge and some distance into the dark side. At some point the particles expanding into the dark side would freeze and form a ridge. Possibly, if enough heat was provided it could cover the entire dark side.
You would not have a constant atmospheric height. So, I assume you would also need some flow of particles back to the center of the lit side to keep the fountain going.
Our model assumes that the atmosphere remains gaseous all around the sphere. Otherwise it would all just freeze to the dark side and there would be no atmosphere. Atmospheric height would be lower on the dark side but would mostly flow back to the lit side at the base as we see with our Hadley and other cells.
KE is not converted to PE. It is converted to entropy.
No, entropy stays the same.
A rising and expanding thermal is not reversible. Most of the pressure of this simple model will be lost to entropy.
Entropy is defined as a thermodynamic quantity representing the unavailability of a system’s thermal energy for conversion into mechanical work,
Conversion of KE to PE renders the thermal energy unavailable for conversion into mechanical work. Thus the entropy of rising air decreases and the entropy of descending air increases.
So KE is converted to PE and that conversion represents a loss of entropy.
Dude, you can’t decrease entropy overall. That’s a fundamental law. And you don’t have a sink to absorb the entropy increase from the expansion.
Dude, overall there is no loss of entropy taking the uplift and descent together.
So a perpetual motion machine? Your model is hosed. Where does the increased entropy go after the thermal rises in your model? You have to have a mechanism for that.
On Earth, clouds radiate the heat to space. This decreases entropy locally and increases density. This is part of the engine for convection.
Yes I did think about this possibility later. I guess the question comes down to is all the diffused thermal energy going to “work” into net lifting of the atmosphere or is a significant portion somehow getting thermally emitted to space. I suppose that if all the gases are assumed to be one or two atom molecules (i.e. non greenhouse) that thermal radiation from the atmosphere will be a non-player. I suppose that makes sense now.
However I’ll say it is confusing the paper is called “Modelling the Climate of Noonworld: A New Look at Venus” yet it assumes no GHG while Venus is practically all GHG so that also threw me off.
menace,
Have a look at our latest paper on Venus in which we resolve the runaway greenhouse gas paradox.
A Modelled Atmospheric Pressure Profile of Venus
.
Not classical climastrology but classic atmospheric physics from the pre-Hansen days.
https://climate-houches.sciencesconf.org/data/pages/Shepherd_WHOI_GFD_1.pdf
You are mixing cause and effect. Air rising IS convection. In Noonworld the atmosphere is stable.
No, in noonworld there is a single three dimensional cell with cool air flowing from the dark side back to the hot noon side. The speed of flow is a function of friction, and noon/dark side temperature differential.
There must be a decreasing temperature with height due to the increase in volume with height as per the Gas Laws.
For the surface of a sphere lit from a point source of light there are inevitably density and temperature differentials in the horizontal plane.
The atmosphere of Noon world cannot possibly be stable.
its happens on earth. Rising air creates a low pressure zone. Descending air a high pressure zone. A pressure differential exists between the dark side to the lit side.
Absolutely right. In its initial form I proposed a vast low pressure cell on the lit side and a vast high pressure cell on the unlit side.
Philip and I then built up from that.
Circular logic. We are trying to find the cause of the convection in this model. Your statement reduces to this: convection is causing convection.
“Your statement reduces to this: convection is causing convection.”
JamesD
Science works in the following way.
If the model we create has value it will produce unexpected results that we can then take and confirm. For example, the temperature difference between the air and the thermal radiator in our Noonworld model is a measure of the tropopause height for Venus. This physical separation arises because the lapse rate, which is a function of gravity and specific heat, is a measure of the store of energy maintained in the atmosphere, and is itself a function of atmospheric pressure and the physical size of the Venusian troposphere. This result is not an input design feature of the DAET model. It is instead an unexpected consequence of the model’s application.
Actually, public discourse allows other interested people to learn a thing or two. If you take this private, while egos are protected from bruising the others of us miss out on discovery of things we either thought we knew or just didn’t know.
I for one really enjoy the discourse between knowledgeable people, as long as it stays civil. So thanks for starting this topic! 🙂
Yes I agree Robert, as a non scientist I struggle with the math but learn and understand much more from the discourse between knowledgeable people, well said.
Also, a major reason for the convection cycle is the buoyancy of water vapor.
True on Earth but not on Noonworld.
On Earth the uplift caused by the buoyancy of water vapour actually causes the larger global convective overturning cycle to slow down because the local uplift and descent becomes faster and the condensate radiates to space. As a result the larger system does not need to return energy to the surface again so quickly to maintain balance.
On Noonworld with no water vapour or radiative gases the overturning cycle would the fastest possible so as to keep the system stable despite the enormous temperature differential between the two sides.
Mars has a very thin atmosphere but no water cycle so the winds periodically become strong enough to whip up planetwide dust storms.
Those dust storms alter planetary albedo so the surface cools and the winds die down until the next time.
Water vapour gives us an unusually benign global climate system compared to dry planets.
What you’re talking about is the temperature decrease with altitude associated with the lapse rate.
That temperature decrease does not provide the equivalent of a “thermal head.” Air following an adiabatic lapse rate temperature profile has a constant “potential temperature.” It is only when potential temperature is decreasing with altitude that the atmosphere becomes unstable and convection can begin. Temperature decreasing with altitude is not sufficient.
* * *
That said, in thinking about how to respond to a comment by Philip, I now believe I was wrong in my assertion that natural convection would not occur on Noonworld.
The understanding which I came to is that a “thermal head” (associated with heat source and heat sink being at different elevations) is a requirement for convection to occur in a closed loop of fluid, but not a requirement for convection to occur in an open system like an atmosphere. I regret my erroneous assertion.
See my comment to Philip for details.
The only place I mentioned “radiative flux” was the same place you did in your paper, mentioning that the surface radiates some energy flux into space.
I wonder if you are referring to my talking about “heat flux” as being being about “radiative flux”?
If so, “heat flux” is a thermodynamic concept, not in any way limited to radiation. It is relevant to all forms of heat transfer, including conduction, convection (of sensible heat and latent heat), and radiative heat transport.
So, I don’t agree that I am “introducing radiative fluxes.”
I have read you saying similar things many times. Yet, every time I hear it, I feel puzzled by why you believe that would have much significance in overall energy transport.
The interchange between KE and PE gives rise to the adiabatic lapse rate, and variation in temperature with altitude.
However, when it comes to energy transport between different parts of the planetary surface, it would seem to have little significance. Except in cases where parts of the surface are at different elevations, the gravitational potential is equal at various points on the surface. So, if air trades off some energy to gravitational potential as it convected upward, it will have regained an identical amount of gravitational energy as it convects downward. The net effect is no difference in energy.
The interchange between KE and PE does change temperature with altitude, but I’m not clear about what significance you might attribute to that.
What am I missing that leads you to believe this topic is important?
* * *
It appears (from other comments) that you’ve shifted towards willingness to have some of this conversation play out in a public process. If so, I appreciate that. As I mentioned in my comment to Philip, I care about engaging in a way that is constructive and respectful, and I’m open to considering other possibilities.
Its what actually CONTROLS the atmospheric temperature.
That is pretty significant.
Insolation, atmospheric mass (and the albedo of that mass) and the strength of the gravity field.
No more and no less.
Sorry, missed the context before my last comment.
The KE and PE exchange controls the surface temperature at a given level of the other factors that I mentioned so fred 250 is correct.
Dr. Wentworth,
Your Thermal Head concept doesn’t seem to apply here.
If I had a perfectly insulated box filled with air at 70 °F, and I put a hot plate on one side of the box, and a cold plate on the other side, with each plate being designed to input or remove exactly the same amount of heat, the air in the box would not get hotter, but it would convect.
“ PE to KE in falling air”
Cold air falling down doesn´t increase temperature. It works like a fan blowing on your skin, it cools. Cold air can´t warm a hot surface in any way, and the atmosphere is very cold.
It doesn’t need to increase temperature. It just serves as an offset against the radiative cooling of the unlit side.
As long as the air from your fan is less cold than the ambient surroundings it will slow the rate at which your hand cools to match those ambient surroundings.
For present purposes those ambient surroundings are the cold of space so as long as the descending air is not that cold it will help to protect the surface from the full effect of radiation to space.
Why is radiation balance of the planet irrelevant. Please answer this single question…..
If the sun supplies energy equal to Ein, what is the energy that leaves the planet, in terms of Ein?
I did not introduce radiation into the atmospheric energy movements. It is not relevant in your model because your atmosphere is defined as having no radiating gasses. But it is most assuredly part of the planetary balance.
I agree that the atmosphere is replete with ke pe ke conversions. Where we disagree is that you only talk about the heat generated by descending air. There is also the heat removed from the surface by ascending air. I maintain that ascending air mass (against gravity) is exactly equal to descending air mass (by force of gravity). Work performed to lifting is exactly equal to the work performed by falling.
While this certainly moves heat from place to place, the NET result is 0 energy gain for the planet surface.
Stephen, you mentioned “private correspondence.” I’m wondering how I could contact you privately (without requiring you to expose your private contact information on the open Internet)?
Bob,
I have a pan of cold water on the gas hob in my kitchen. I turn on the gas and light the flame. I am reasonably confident that a circulation cell of water will spontaneously develop in the pan.
I echo Stephen’s comment. You know who we are and how to get in touch with us.
As has already been pointed out above (which I am echoing here), discussing these concepts openly here is a feature, not a bug.
I must say that I initially thought it was going to be a problem attempting to discuss these matters in a hostile environment but so far that fear has been misplaced so Bob may have done us a service after all.
My compliments, Mr. Wilde.
Real science. People challenge the findings and progress is made.
Philip, it makes sense to me that having dialog about your work unfold publicly in ways that seem to give a high profile to what you likely feel are (and could be) misunderstandings, would seem troublesome. I care about that issue, and occasionally feel uneasy about it. I very much want to be contributing to a respectful, constructive process. I also see significant value in having a public process, as long as it is conducted in a manner consistent with those values. I’m open to the possibility of finding a different strategy for sorting through the issues, if it also includes some way of, ultimately, caring for public understanding. It’s also nice to be able to draw upon the potential wisdom of others. I don’t yet have any clear ideas about a better strategy of engagement. I’m happy to mull it over. And, I’m willing to hear more ideas about the subject.
In the meanwhile, I’m hoping it’s okay to continue to thoughtfully engage in these comment threads.
Thanks for that example. I think it’s useful to think that through. It’s nice to think about water, because it eliminates the added complication of compressibility that enters the picture when one is thinking about air.
My first thought was that there is an elevated heat sink, insofar as heat is convected away from the top surface of the water.
But, what if one seals the water inside an insulated container?
When you first turn on the heat, the hot water at the bottom will be less dense than the water above, and so convection (likely turbulent) will begin.
The condition of needing an elevated heat sink to create a “thermal head” refers to steady state conditions. So, let’s modify the scenario into one in which a steady state is possible.
Suppose we’ve got an insulated container full over water. At the bottom on the left, there is a heat source at fixed temperature T1, and at the bottom on the right is a heat sink at fixed temperature T0, where T1 > T0.
As you note (I think correctly), during the initial start-up, natural convection will spontaneously occur. Maybe that’s simply a transient phenomenon?
What is the equilibrium condition? As a hypothesis, let’s suppose the equilibrium state is one in which the temperate is only a function of the horizontal position, x, between the heat source and the heat sink, with temperature not varying at all as function of height, z, above the bottom.
Let’s see if there is anything preventing this from being a stable state of equilibrium.
And because there are no temperature variations along a vertical axis, there are no vertical density variations to create buoyancy and drive convection.
Because temperature varies along the horizontal axis, x, density will also vary along this axis. However, there is nothing wrong with that, as long as there is no pressure variation along a horizontal axis.
Suppose the pressure is the same everywhere along some horizontal line. But, we know pressure must vary with height according to dP/dz = -ρ⋅g. So, if the density is different for different horizontal coordinates x, then the steepness of the vertical pressure gradient will also vary with x. That means the initial hypothetical equilibrium state doesn’t have uniform pressure at all elevations z.
Near the heat source, water will be less dense, and there will be less variation in pressure with height. Near the heat sink, water will be more dense, and pressure will vary more strongly with height. This predicts that at the top of the container, the pressure will be higher on the hot side and lower on the cold side, while at the bottom, the pressure will be lower on the hot side and higher on the cold side.
Wow. That certainly sounds like a setup that would lead to convection happening.
Rather to my surprise, this is suggesting the possibility that I was wrong about convection not happening in the absence of an elevation difference between the heat source and heat sink.
How can I reconcile this with the information I was drawing upon?
In reaching my original conclusion, I was relying on what I had read about natural convection and the need for a “thermal head.”
I notice that some (but not all) of the sources talking about the need for a “thermal head” were specifically talking about the context of a closed loop of fluid, such as one intended for passive convective cooling of a nuclear reactor. Thinking about the analysis of such a closed-loop system, I believe it’s correct that convection in such a system will occur only if there is a “thermal head”, or elevation difference between the heat source and heat sink.
Is there a significant difference between a closed-loop system and an open container of fluid?
It occurs to me that there is a difference.
The difference is that the upper and lower portions of the circulatory loop are thermally isolated in a closed-loop system, but are in thermal contact with one another in an open container.
In the closed-loop system, the fluid in the top of the circulator loop maintains the same temperature until it reaches the heat sink. And the fluid in the bottom of the circulatory loop maintains the same temperature until it reaches the heat source. This is what leads to a “thermal head” (elevation difference) being required.
However, in an open container, the thermal contact between the upper and lower circulation loops means that temperatures, and consequently densities, can change as the fluid moves horizontally. This leads to a situation where the sort of difference in vertical pressure profiles that I noticed above will, in fact occur, leading to pressure differences that would drive convection.
The conclusion I’m coming to is that I expect a “thermal head” to be required for natural convection to occur in a closed-loop system, but for a “thermal head” to not be required for natural convection to occur in an open container of fluid—as in the atmosphere of Noonworld.
I think I was wrong about convection not happening on Noonworld.
I apologize for the impact of asserting something (“convection won’t happen”) that was, in retrospect, apparently mistaken.
Bob Wentworth, I agree. See my comment at 5:21 PM (above) which was,
“Your Thermal Head concept doesn’t seem to apply here.
If I had a perfectly insulated box filled with air at 70 °F, and I put a hot plate on one side of the box, and a cold plate on the other side, with each plate being designed to input or remove exactly the same amount of heat, the air in the box would not get hotter, but it would convect.”
Bob,
I am happy to continue to engage on the thoughtful basis you describe.
Perhaps if you had sent your draft to us first we could have avoided the unfortunate use of figure 2? You correctly describe the balance process of figure 3 in your text but folk here see the diagram first and justifiably complain that figure 2 is not in balance.
The key point is that Noonworld never reaches stasis. The mass and energy flow in the model are a dynamic equilibrium that continues in perpetuity.
https://www.drroyspencer.com/2009/12/what-if-there-was-no-greenhouse-effect/
Yes, I have engaged with Roy over the years.
He still thinks that there would be no convection on Noonworld and that the atmosphere would be isothermal with the same temperature everywhere in the absence of GHGs.
My explanation as to why that was impossible was not well received.
I don’t understand why the atmosphere would be isothermal, but he is right about “And without a falloff of temperature with height in the atmosphere of at least 10 deg. C per kilometer, all atmospheric convection would stop.” (or 9.8 deg.)
When there is no cooling aloft it is impossible to get the lapse rate higher than 9.8
The lapse rate is present by virtue of expansion with height. GHGs not required.
Yes, a lapse rate of 9.8, which is not enough to get convection.
I do not know how to get in touch with you. I’ve been trying to figure that out, without any luck as yet. How could I do that (without your needing to publish your contact information openly on the Internet)?
Bob,
My apologies.
I have wrongly assumed that if you went to my Research Gate site you could contact me from there.
With regard to atmospheric and oceanic heat transfer, I did this calculation for the temperature of an Earth-like planet where heat is distributed in a completely even manner. It makes some simplistic assumptions for sure but it does obviate the need for a greenhouse effect.
Our work fits in with Jim Steel’s article and your comment just fine. The oceans and the hydrological cycle introduce a level of internal system variability that operates within our concept. I first wrote about the effect of ocean cycles over ten years ago.
Convection between the light and dark side MUST happen as there will be a temperature and pressure difference at that boundary which will indeed provide a pressure head and induce circulation. As the hot air at the boundary overrides the colder air it will rise and the cold air will back fill underneath. It is like a perpetual frontal boundary that will likely go all the way around the planet as it will happen over the poles as well.
In response to further thought which I unpacked in a comment to Philip, I now believe that you are correct.
“So, on Noonworld, the Dark side partitioning ratio is always 𝛾ₒ = 0. The entire convective heat flux from the warm air always flows into the cold surface.”
Forget the idea of a heat flux which is a radiative concept. What is happening is that as the air descends an amount of PE converts to KE and is quickly absorbed by the cold surface which is radiating rapidly to space. That KE reduces the cooling effect of the radiation to space and the surface ends up warmer than it otherwise would be. That warmer surface air then flows horizontally back to the lit side which is still receiving the full effect of insolation.
Thus the lit side is receiving both full insolation and air from the unlit side that is warmer than it otherwise would be. Therefore the surface on the lit side must also become warmer than it otherwise would be.
That is the reality of the so called greenhouse effect.
The basic concept is painfully simple but modelling and quantifying is fiendishly complicated hence Philip’s involvement.
It is currently far from perfect but nevertheless it is throwing up predictions such as troposphere heights that accord with observations.
We are steadily relating our model to increasing numbers of features in the atmospheres of Earth, Mars, Venus and Titan and refining it as we go.
The basic Noonworld model is the starting point since it strips down the variables to a non rotating planet and a radiatively transparent atmosphere.
We then add back rotation, atmospheric radiative opacity and other features to the basic model to see how they cause the pattern of convective overturning to vary.
The essential finding is that the pattern of convective overturning changes to neutralise all imbalances in order to retain hydrostatic equilibrium for the atmosphere as a whole.
For example a fast rotator like Earth has three atmospheric convective cells whereas a slow rotator like Venus makes do with one.
Philip constantly comes back to me with new insights about those various solar system atmospheres when he finds that our model explains or describes additional observed features.
A major issue has always been as to how solar input onto a very opaque atmosphere gets to the surface of Venus in order to drive the powerful winds within the atmosphere. Our model explains that by pointing out that any thermal disturbance beneath the moving zenith will provoke convective overturning to the full depth of the atmosphere so that the conversion of PE to KE in the descent delivers a vast amount of heat to the surface from the top of atmosphere disturbances caused by the sun.
We are currently analysing Mars and finding that our model can accommodate the energy requirements of the periodical planetwide dust storms on Mars.
The atmosphere above the surface is cooled both by radiation to space from the surface and by uplift and expansion on the lit side.
On the unlit side the atmosphere is cooled from the surface only but the atmosphere delivers KE from the lit side back to the surface to reduce surface cooling.
When the atmosphere delivers KE to the surface its temperature increases and the LW cooling increases. The opposite of your claim. You are creating energy.
No energy is created or destroyed merely transformed to and fro between KE and PE.
The delivery process is constant but variable and LW cooling can only increase to match the rate of delivery. The outturn is a surface warmer than it otherwise would be
This point is important because faster delivery will lead to faster LW cooling which is exactly how the system adjusts to imbalances, namely by altering the speed of delivery to the unlit side. That change in delivery rate is driven by lapse rate distortions caused by greenhouse gases or indeed any other destabilising factor.
It is a self adjusting system whereby imbalances from any cause can be neutralised in order to ensure continuing hydrostatic equilibrium.
“The outturn is a surface warmer than it otherwise would be” If so then LW out would exceed SW in. Creation of energy.
Well, no because the surplus energy goes into convective overturning and there is no excess of LW out exceeding SW in.
Uplift on the lit side prevents radiation out to space exactly equal to descent on the unlit side increasing radiation out to space for a zero net effect in relation to space but a constantly circulating store of PE within the atmosphere on both sides.
If no excess LW, no elevated surface temperature. (and the atmosphere is not warmer than the surface because that’s where all the atmospheric heat is coming from)
And again, there is no convection. And if there were, the KE to PE and back to KE would not increase/create KE.
On the night side there is increased KE beneath the descending circulation but no excess LW radiation to space.
On that side the atmosphere is warmer than the surface because of the KE released in the descending flow.
Note that we are considering the large scale planetary circulation involving the entire atmosphere, not local conditions.
Energy at the surface must be partitioned between radiative escape to space and participation in the continuing convective overturn.
A single unit of energy cannot be in two places at once or perform two jobs of work simultaneously.
Beneath a convecting atmosphere the surface does not radiate to space at a rate commensurate with its temperature. Only at the so called radiative emission height will it do that.
The S-B equation relates to a body in a vacuum and not a surface beneath a convecting atmosphere.
At the surface the amount of radiation escaping the atmosphere to space will be affected by the speed of convective overturning.
Our model apportions surface KE between that which gets out to space and that which is locked into convection.
We are finding that such an apportionment leads to a better description of the observed behaviour of atmospheres and allows prediction of various features of those atmospheres.
“Only at the so called radiative emission height will it do that”
And in this case the surface is the radiative emission height. So, wrong again.
“The S-B equation relates to a body in a vacuum and not a surface beneath a convecting atmosphere.”
Nonsense.
“At the surface the amount of radiation escaping the atmosphere to space will be affected by the speed of convective overturning.”
More nonsense.
lgl
For Noonworld the emission height is indeed the surface which doesn’t change the sense of my point.
As regards S-B the radiative theory accepts that the S-B temperature is taken from space i.e. in a vacuum but that greenhouse gas radiation within the atmosphere raises it. Therefore that agrees with my statement that the S-B equation applies only to an object in a vacuum.
All I am saying is that the reason for the higher surface temperature is convection and not radiative gases so my comment is certainly not nonsense.
The radiative theory accepts that radiative gases slow down radiation to space as does my convection based hypothesis. If one is nonsense then so is the other.
My position is that both options are plausible but mine answers more questions and is therefore correct.
“my convection based hypothesis”
Yes, that’s the problem. No basis in well known physics. Why on earth would convection slow down radiation to space? And how is KE to PE to KE creating more KE?
Simply because energy is retained in the form of non-thermal PE within the convective overturning system and PE cannot be radiated away.
My hypothesis is designed around well established physics especially in the field of meteorology.
When a photon is emitted from the surface. How is convection converting it to KE or PE? And why does it matter whether or not the air molecules are moving a few m/s up or down?
Conduction removes KE independently of photon emission then convection takes it higher converting KE to PE in the process. That conductively removed energy reduces the frequency of photon emission to less than it otherwise would have been. The surface temperature doesn’t need to drop because the energy going into conduction is constantly replenished by further insolation. On a planetary scale the movement is right up to the tropopause and the rules are slightly different above that point.
The outcome at the surface is that the surface temperature will not be emitting photons at the rate predicted by S-B because of the diversion to conduction and convection.
Diversion to conduction and convection cools the surface. So, I’m puzzled by what you’re saying.
Shortwave and longwave radiation absorbed by the surface must be matched by energy leaving the surface. Energy leaving the surface includes 𝜀σ<T⁴> + V where V is the heat flow from convection.
So, increasing V leads to T being lower, i.e, convection cools the surface.
But I think somehow you’re thinking convection warms the surface?
On the night side descending air supplies a constant flow of fresh KE at the surface derived from PE higher up. That doesn’t warm the surface but acts as an offset against surface radiation to space so the surface doesn’t get as cold as it otherwise would.
Well, of course warm air from the day side warms the surface on the night side.
That heat is not “derived fro the PE higher up”. That heat is put into the air on the day side. Then the air exchanges KE&PE going up, and exchanges KE&PE going down — but the net effect of PE is zero. The heat all came from the heat put into the air on the day side.
The issue of PE seems irrelevant.
But there is a circulation with an energy content which needs to be maintained by additional KE at the surface over and above that required to match radiation out to space with radiation in from space. So the conversions between KE and PE are the cause of the greenhouse effect.
Yeah, without fully studying this, talking about PE after an isenthalpic expansion is worrying. All of the KE is chewed up by entropy creation.
PE creation is a form of entropy creation since the thermal energy from which it is created is no longer available for mechanical work. Entropy declines in uplift but increases in descent.
If your model depends on entropy reduction, it is wrong.
Obviously it does not.
The entropy lost in uplift is regained in descent for a zero net effect on total entropy.
G = H – TS. In an isenthalpic expansion, H is constant. TS increases. So free energy is lost. Entropy is not “lost” in uplift, it increases. Free energy is what is lost in uplift.
If the “surface” air is colder than the “higher” air, how would the “higher” air descend into the denser air? Keep in mind that the “higher” air will be less dense than expected due to the increase in entropy. I don’t see any driving force for the descent.
Forced convection is the term used in meteorology. Once low density air at the surface starts to rise it pushes the air above it to one side and the air at the top has nowhere to go but downwards. The descent is aided by the fact that the higher air has become so cold that it starts off slightly denser and thus heavier than the slightly warmer air beneath (colder air normally being denser) which it then displaces as it descends. In an adiabatic descent with no energy added or removed the density difference with the surrounding air remains stable all the way down so there is nothing to stop the descent.
Adiabatic processes are tricky to envisage but are well proven. It is basically an interplay between density as affected by temperature and density as affected by height. When density is related to low temperature it will overcome the increase in density induced by gravity as one descends.
When air is heated and rises, it is forced upward by a buoyant force which is doing work on it. Since work is being done on it, it will not cool because of the conversion of KE to PE. Taking a tank of air up a mountain won’t cool it, because work is done to lift it. An open container, however, will cool because of approximately adiabatic expansion. And, there is a lapse rate. This lapse rate will develop in a gravitational field as you suggest, based on KE to PE conversion. There is no need for greenhouse gasses to cool the upper atmosphere (see Saturn’s tempreature profile). No work is being done to the gas.
Considering only vertical components: a column of gas has molecules moving randomly, and this column will have a lapse rate based on the conversion of KE to PE. This is easily demonstrable in a lab using an air track. So while you are correct in many ways, I believe that your explanation of why a batch of warm air rising cools is incorrect.
I’ve seen that reference to a buoyancy force before but it just confuses matters.
It is a sort of shorthand for the tendency for less dense materials to rise above more dense materials in a gravity field There is no discrete force in nature known as the buoyancy force.
Work is done in uplift/expansion and descent/contraction because otherwise there would be a breach of the conservation of energy. It is the application of work that allows the conversion process between KE and PE and back again but that work is done first against and then with, gravity.
I agree that there is no need for greenhouse gases to cool the upper atmosphere.
I don’t have the heart to break it to Archimedes.
That is Archimedes Principle which is not a discrete force in nature merely a description of what happens as a result of the tendency for less dense materials to rise above more dense materials in a gravity field.
Stephen Wilde,
The buoyancy force is real. It is a net force of all the contact forces acting on the body plus gravity (which is usually negative). If the gas were not expanding (like a bubble rising through water in an insulator), then it would not cool, it would just rise to an isobaric elevation. This can be shown experimentally. I don’t believe that this refutes any of your general conclusions, mind you, since the gas is cooled as it rises by a similar amount through expansion. Maybe it alters some calculations? It is a column of gas that is not acted on by an outside force where a lapse rate develops, independent of any greenhouse gases.
I can accept that general description but there are only four fundamental forces of nature and buoyancy is not one of them.
That is probably true for most forces, then, like contact forces. I guess you could say, then, that it is an electrostatic force. The sum of all the electrostatic forces pushing on the object (or batch of gas) minus gravity gives you the net force, which is called the buoyant force.
“That warmer surface air then flows horizontally back to the lit side which is still receiving the full effect of insolation.”
I’m missing something. What keeps that warmer surface air from getting warmer and warmer every trip around the globe? Every time it goes around to the lit side the insolation is going to pump it up higher. Unless it somehow loses all that gained heat it will just keep getting hotter and hotter.
Because the speed of convective overturning adjusts to ensure that the energy held at the surface is just enough to allow radiation to space to match radiation in from space AND support the energy requirement of the convective circulation in maintaining long term hydrostatic equilibrium.
Overturning will always run at a speed that keeps the system stable. The speed of overturning being linked to the lapse rate slope set by mass and gravity. Any distortions to the lapse rate slope that might destabilise the system will inevitably alter the rate of convective overturning in an equal and opposite negative reaction.
“That warmer surface air then flows horizontally back to the lit side ”
Therein is that missing pressure difference that someone complained about.
EdB
The action of sunlight on the surface of the Earth expands the atmosphere. On the daylit side of the Earth the average elevation of the tropopause is higher than that found on the night side.
I’m puzzled by this belief. “Heat flux” is not a radiative concept. It is a thermodynamic concept. It applies to all forms of heat transfer, including conduction, convection of sensible heat, convection of latent heat, and radiative heat transfer.
If you insist on discounting the idea of “heat flux”, then you are disregarding thermodynamics. That will almost inevitably lead to mistaken thinking that includes non-physical processes which violate the Second Law of Thermodynamics. It appears that that has been happening in your work.
It’s possibly that you might want to develop a theory that is tracking something other than heat fluxes.
If so, that’s fine. However, it will also continue to be valid and essential to be able to analyze your model in terms of heat fluxes. And, if that analysis at the level of heat fluxes reveals a violation of the Second Law, that means that the model is non-physical, and cannot represent reality.
If you are going to work with something other than heat fluxes (and then only check your work by also checking on the heat fluxes), then it is essential that you rigorously define what these quantities are that you are tracking.
Regrettably, I have the impression that what you are tracking is only vaguely defined. That easily allows arbitrary assumptions to be made which end up having no correspondence with actual physics, and which are inconsistent with established principles of physics.
It turns things into modeling how things might work in a game world, rather than modeling something grounded in the extremely solid base of classical physics, which is so reliable that it underpins all the technological marvels of our world, with principles that have proven themselves countless times.
Natural convection is a thermodynamically driven process. It must obey the laws of thermodynamics.
What do you mean by saying the “air from the unlit side” is “warmer than it would otherwise be”? You mean, I suspect, that it is warmer than air from the unlit side be if warm air had not flowed to the unlit side to bring some heat with it.
Yet, the bottom line is cold air is flowing to the lit side. (The air is colder than the surface on the lit side.) Yet, you are concluding that this flow of cold air makes the warm side warmer.
You seem to be getting confused by your own mathematical formalism into postulating a non-physical process.
* * *
Of course, that’s very similar sounding to the arguments that I hear from people denying the radiative greenhouse effect. And, it’s clear to me that those arguments are wrong, a result of not carefully thinking things through. So, I don’t want to make the same mistake here.
Let’s see if I can imagine what you might mean…
I suppose you’re thinking about an iterative process, in which you start from a particular starting state (everything very cold), insolation starts, air is circulating, and the state of the system changes after each iteration.
So, when you say “air from the unlit side that is warmer than it otherwise would be,” you mean that the air from the unlit side is warmer than it was on the prior iteration.
Hmm. I agree that that is a valid statement.
—
I got to that point in my comment half a day ago.
I’m realizing that I probably did err in treating the flows your were envisioning as heat flows.
I’m still quite certain that there is a valid heat flow perspective, and that there is a problem with your model in that regard.
However, the way I addressed the issue in my essay wasn’t quite right.
It’s going to take me a while to figure out to express my concerns about this correctly and clearly.
In the meanwhile, sorry for yet another layer of confusion.
I so often hear about a radiative flux that I tend to associate heat fluxes with radiation.
The thing about adiabatic uplift and descent is that there isn’t really any heat flux within the process because the heat disappears during uplift and doesn’t reappear until the descent so there is obviously no heat flux within the main body of the adiabatic process.
You could say that there is a heat flux at each end though. There is a heat flux from surface to atmosphere in uplift and a heat flux from atmosphere to surface in descent.
But that is just semantics.
The reality is that uplift removes heat from the surface in one location and descent returns it to the surface in a different location with no addition or loss of energy in the process.
So that delay in loss of energy to space, that energy flow stasis, results in an accumulation of energy within the system and so system temperature must rise.
As for cold air flowing from the lit side to the unlit side but yet making the unlit side warmer you are again ignoring a relevant key factor. The air from the lit side may be cold at the top due to adiabatic expansion but by the time it gets back to the surface on the unlit side it has become a great deal warmer by adiabatic contraction.
You need to think in three dimensions.
I am sorry that my narrative takes various meteorological principles for granted. Principles that are obviously not shared by many others who have no previous experience of meteorology.
I think you’re using “heat” in the informal sense of referring to internal energy. In a rigorous thermodynamic sense, “heat” only refers to the transfer of energy between two bodies (subject to certain specifics).
So, in that sense, there isn’t any disappearance of heat during uplift or appearance during descent, though internal energy appear and disappear during those process.
“Heat transfer” may be regarded as being present in this context in a number of distinct ways:
Yes. That’s heat transfer #3 in my list.
This heat transfer is unaffected by any conversions between KE and PE along the way.
Figuring out the impact of a “delay” requires more careful reasoning than I have yet seen be applied.
Maybe one of these days I’ll get a chance to think through and to write down the exact mathematics of how this does and doesn’t work. I recently started working through the impact of energy residence time.
I don’t think you accurately tracked what I said. I said “cold air is flowing to the lit side.” So, I was referring to near-surface air flowing from the cold Unlit side to the warm Lit side. This air flow doesn’t involve anything changing in elevation.
I have no trouble thinking in three dimensions. If I ever have trouble understanding you, that’s unlikely to be the problem.
I have no trouble at all following the meteorological parts of what you say. It’s the inferences about physics that you make, as you think about those meteorological principles and phenomena, that I often have trouble making sense of.
You just need to consider the PE released in descent as an offset against radiation to space from the unlit side. The air on the unlit side never gets as could as it otherwise would and so when it returns to the lit side its cooling effect on the lit side is similarly compromised and given that there is still full solar input on the lit side the temperature there must rise as well.
It is basically an accounting issue and that is the best I can do for you.
“Under full summer sun conditions, short term dry surface temperature can easily exceed 50ºC. However, the increase in blackbody LWIR flux as the temperature increases from 20ºC to 50ºC is only 200W/m2. This means that most of the solar flux is coupled back into the atmosphere by convection, not thermal radiation.”
from “The Dynamic Greenhouse Effect and the Climate Averaging Paradox” by Roy Clark
https://www.abebooks.co.uk/servlet/BookDetailsPL?bi=30404396023&searchurl=ds%3D20%26kn%3Dthe%2Bdynamic%2Bgreenhouse%2Beffect%2Band%2Bthe%2Bclimate%2Baveraging%2Bparadox%26sortby%3D17&cm_sp=snippet-_-srp1-_-title1
“Any discussion of climate change must explicitly include ocean solar heating and long range ocean transport since these are the primary mechanisms of climate change.”
from “ditto”
Thank you.
I am aware that the basic idea of a dynamic rather than radiative greenhouse effect existed at least from the mid 20th century when I first learned the basics of meteorology. It was always said that the surface of Venus was so hot because of the density of the atmosphere, not its composition. However, so far as I know, nobody has previously gone into the detail in order to demonstrate the invalidity of the radiative physics takeover of the 1980s onwards.
We have now demonstrated that it is convection and convection alone that leads to the surface temperature enhancement that has thrown everyone into a state of panic and now threatens the stability of western civilisation.
This “Noonworld” scenario illustrates the problem with over-simplified models disconnected from reality. Has anyone ever found a planet or moon with the same side always facing the sun, with a totally transparent atmosphere? Mercury always has the same side facing the sun, but due to its weak gravity and proximity to the sun, it can’t hold an atmosphere. The Moon always has the same side facing the earth, but since it revolves around the earth every 29 days, the side invisible from Earth is sometimes sunlit half the time, and the Moon also has no atmosphere.
Simplistic models using only convection and radiation may work fairly well for a system involving only a heat source (such as the sun), a solid planetary surface, and a gaseous atmosphere, where there are no phase changes (solid to liquid to gas, or vice versa) involving transfer of latent heat.
But Earth is a very wet planet, with about 70% of its surface covered by liquid water, and part of its colder land areas covered by ice and snow. Not only do both liquid water and ice and snow reflect most of the sun’s radiation, but they have a huge specific heat and latent heat required to change phases.
At sea level pressure, air has a specific heat of about 0.31 kcal per m3 per degree C, meaning that 0.31 kcal of heat are required to raise 1 cubic meter of air from 0 C to 1 C. Pure water has a specific heat of about 1,000 kcal/m3-C, meaning that 3,200 times more heat is required to raise the temperature of 1 m3 of water by 1 C than 1 m3 of air. The heat required to melt 1 m3 of ice is about 73,000 kcal / m3, or about 237,000 times the heat required to warm 1 m3 of air by 1 C.
So, when climate modelers say that additional CO2 in the atmosphere would capture enough radiant heat to cause the average temperature of the atmosphere to increase by (for example) 1.5 C in 100 years, how much ice could be melted and contribute to sea level rise?
At sea level pressure, the mass of atmosphere above 1 m2 of the surface is about 10,300 kg/m2, and the air density at the surface is about 1.226 kg/m3 (at 15 C). This means that the effective depth of the atmosphere (relative to sea level pressure) is about 10,300 / 1.226 = 8,400 m.
Assuming that additional CO2 could heat up the atmosphere by 1.5 C in 100 years, for every m2 of the earth’s surface, this requires 8,400 m3 * 0.31 kcal / m3-C * 1.5 C = 3,906 kcal of heat, which would be enough to melt 3,906 / 73,000 = 0.0535 m3 of ice per m2 of surface area, or a depth of 53.5 mm (about 2.1 inches) in 100 years.
It’s relatively easy for a climate modeler to claim that additional CO2 in the atmosphere could warm it by a degree or two, due to the low specific heat of air, but the oceans and ice caps are huge heat sinks, and the amount of heat that can be absorbed by CO2 in the atmosphere has very little effect on them.
All very true but in this case the simplified model reveals an underlying truth. Once convection (and convection can never be prevented) is present the surface temperature will rise above S-B and all potential radiative imbalances will be neutralised by a change in the rate of overturning.
All without consideration of radiation at all.
That is why the temperature within the atmosphere of Venus at the same pressure as the surface of Earth is approximately the same as that on Earth after adjusting only for distance from the sun and despite the vastly different atmospheric composition.
Radiative physics has no explanation for that.
But the ideal gas laws do.
Yes indeed.
That is the heart of it.
I actually applaud the attempt. We need someone to start simple because climate “science” is royally screwed up.
Steve Z,
You must be my age! We learned that Mercury is tidally locked and has one face always at the sun. This is incorrect, however, and while Mercury is tidally locked, its a 3:2 ratio I believe, and so it does not have a perpetually bright side. While this does not have anything to do with your arguments, there are those, particularly who take sides in a climate debate, that will try to invalidate your main points and confuse issues based on an inconsequential error.
Perhaps there is an pneumatic overturning pumping action introduced by uplifting mass vs gravity. Compressed gas provides all sorts of interesting mechanical effects. External energy input provides energy to get it going.
haha I’m the champ of getting downvotes. Just throwing stuff up against the wall – maybe something will stick one of these days.
Your comment wasn’t far off so I’ve given you an uptick.
Thanks Mr Wilde I will take it!
I am seeing the problem through the lens of mixed convection, including forced solar convection + pressure induced (mostly horizontal) buoyant convection. These flows can have some opposition to one another and so might reduce total net heat flow rates (aloft). Could be that strong sun induced thermal updrafts are opposed (or enhanced) by horizontal pressure induced shear (in 3d). Turbulent eddies at various scales result providing some net energy flux storage (delay?) mechanism. Not sure if i’m using the exact right words but that’s the idea..
I guess, then, the magnitude of the opposing forces in my conceptual understanding are proportional to solar input and pressure, resulting in a proportional energy storage term. This term represents a seemingly random horizontal shear factor turbulence inducing energy recycling thing, unfortunately!.
JCM,
You are right it’s complicated. On rapidly rotating planets like the Earth we need to add the “pumping mechanism” of the Coriolis effect and the resultant feature of forced air descent in the mid latitudes due to conservation of angular momentum. I would not claim that we have all the answers, what we are attempting to do is present an alternative, meteorological based road map for climate with Noonworld as our start from here point of reference.
thank you Mr Mulholland. It’s a thought provoking idea. I think my imagination is taken a left turn by introducing the horizontal shear component but for me this helps tie it into my concept of real planets.
I do recognize the premise of your work being KE to PE reducing radiative losses at the top of overturning mass movement, however, it’s a tough concept.
JCM
This was only the starting point, the next thing that came out of this for me was the addition of the environmental lapse rate and opacity caused by condensing volatiles. There is good reason to suspect that there is an interlocking relationship between the freezing point of a planet’s condensing volatile (super-cooled water for the Earth and concentrated sulphuric acid for Venus), and its Bond albedo.
High elevation solid particles are efficient thermal radiant emitters to space as well as being reflectors of sunlight. The tropopause elevation (the point of minimum atmospheric temperature at the top of the convecting overturn system) and its temperature are co-linked variables with surface atmospheric pressure.
It is a tough concept for those who know no meteorology but in addition there are many who are emotionally driven not to accept it since it causes problems in their world view given that they see everything that mankind does as malign.
Maybe I’m reading the schematic wrong, but Noonworld is not in heat balance. You have 1 unit of heat coming in, and 0.75 units of heat leaving.
Perhaps Philip could respond to that since he designed the schematic.
JamesD,
You are quite correct Figure 2 is not in balance, it was used to illustrate the devlopment of the process, it is Figure 3 (not shown here) that gives the state of balance.
“The heat flux will only travel from hot to cold. If the air circulates back to a hotter place, the heat flux will not go with it.”
Don’t you mean the “Net heat flux” must go from hot to cold? Certainly some photons can transfer from the cold to the hot, but the net transfer of energy (so most of the energy carried by photons) must be from hot to cold.
Also, would there not be some air movement caused by the rotation of the planet? While it is tidally locked, it is still rotating. Air masses have inertia so there must be some transfer of energy to the movement of the air.
Simple examples never seem to stay simple once one really thinks through the entire system – which I think was your original point.
So…”Imagine the Earth is a perfect cube” (thought process of a climate scientist)
I don’t see where rotation of the planet was addressed but I would assume for it to play much of a role the planet would need to be very close to the star so that its tidally locked orbit would coincide with a rotation fast enough to make much of a difference.
Robert,
Noonworld is a modelling concept, its purpose is to force the issue of requiring a climate model to use divide insolation by 2 as an input. Slowly rotating Venus is the closest approach to a tidally locked planet that we can observe directly.
I understand the concept, I was simply responding to Robert of Texas’ question about rotation and I don’t see where I was wrong. I assume in your model that the planet is far enough from the star that the rotation is extremely slow in order to be tidal locked?
The quotes by Robert of Texas were from a previous commenter not me or Philip.
“I was simply responding to Robert of Texas’ question”
Robert,
My apologies.
Stephen & Phil, Robert of Texas was quoting from the article.
The full quote is,
“Convecting air can carry a heat flux, but that heat flux is not constrained to stay with the air. The heat flux will only travel from hot to cold. If the air circulates back to a hotter place, the heat flux will not go with it.”
I don’t understand what the author means by that. As Robert of Texas would presumably know, a lot of very cold air traveled to warm Texas in February of this year. A few days later, warm air traveled back to cold Texas, and warmed it up again.
None of that invalidates the 2nd Law.
If I recall correctly, Texas warmed from -15 °F to + 75 °F in three days. That’s 90 °F of warming, or 30 °F every 24 hours. The cold killed some people, the rapid warming didn’t.
I also don’t buy the author’s “Thermal Head” argument. If I had a perfectly insulated box filled with air at 70 °F, and I put a hot plate on one side of the box, and a cold plate on the other side, with each plate being designed to input or remove exactly the same amount of heat, the air in the box would not get hotter, but it would convect.
“the air in the box would not get hotter, but it would convect.”
Thomas,
I totally agree with you, hence my comment about heating a pan of cold water on a gas hob.
Thanks for also pointing this out:
” the heat flux will not go with it.”
The mobile fluid in our model is an energy transport mechanism.
In this case, the warm air essentially carried a heat flow from the place where the was warmed to Texas.
In this case, a heat flux passed from Texas into the cold air.
Thinking about the relationship between heat flux and air currents is admittedly messy. Possibly not the best way of thinking about things.
As I’ve noted, I was wrong about the “Thermal Head” argument in the case of the atmosphere.
Dr. Bob, You are a gentleman. I suspect you might also be an alien life form. Humans don’t normally so gracefully admit to having made an error, no matter how minor.
So the model can transport heat without a thermal head. The part that I don’t get is how does that heat transport make the entire atmosphere hotter that it would otherwise be? It looks to me like it just makes the hot side cooler, and the cool side hotter. Is gravity somehow doing work on the atmosphere? I guess I should actually read the paper. : )
No such thing as a nett heat transfer, just more luke-warmer and alarmist bollocks.
The returning photons from cold objects to warmer objects simply replace the same wavelength photons that were emitted a millisecond prior by the warm object, there is no increase in the resident energy / frequency of the warm object.
No work no heat no increase in energy simple as that, ”heat flows one way hot to cold.
Heat is defined as any spontaneous flow of energy from one object to another caused by a difference in temperature between the objects. We say that “heat” flows from a warm radiator into a cold room, from hot water into a cold ice cube, and from the hot Sun to the cool Earth. The mechanism may be different in each case, but in each of these processes the energy transferred is called “heat”.” – Thermal Physics, D. V. Schroeder, Addison Wesley Longman, 2000
Perhaps the most important type of thermodynamic process is the flow of heat from a hot object to a cold one. We saw […] that this process occurs because the total multiplicity of the combined system thereby increases; hence the total entropy increases also, and heat flow is always irreversible.
Thermal Physics, D. V. Schroeder, Addison Wesley Longman, 2000
definition of heat is:
Heat is energy transferred across the boundary of a system as a result of a temperature difference only.” – Classical and Statistical Thermodynamics, A. H. Carter, Prentice-Hall, 2001.
Heat is defined as the form of energy that is transferred across a boundary by virtue of a temperature difference or temperature gradient. Implied in this definition is the very important fact that a body never contains heat, but that heat is identified as heat only as it crosses the boundary. Thus, heat is a transient phenomenon.
Thermodynamics, G. J. V. Wylen, John Wiley & Sons, 1960
And ps space is not a heat sink, heat does not exist in space, its an energy sink s space has no temperature.
”2.7K is the equivalent blackbody temperature of the cosmic microwave background radiation. This is NOT the temperature of space!.
Radiant energy can be equated to a temperature which a material blackbody would have in equilibrium with it via the Stefan-Boltzmann Law. This is NOT the temperature of space”
The earth does not radiate ”heat” to space, it radiates energy, that energy is only potential heat, and its potential will never be met because there no boundaries to cross no mass for the energy/ radiation to thermalise in.
The Noonworld is clearly wrong since it gets the right temperature for a planet like Venus without including the effect of greenhouse gases. Suppose for a moment that the analysis was correct and then you include an atmosphere composed of CO2. Now ask what happens to the temperature? I would assume that Mulholland and Wilde accept that CO2 absorbs and re-radiates long wavelength radiation and therefore it traps additional energy in the atmosphere (They certainly appear to agree with that in their analysis of Earth’s energy budget). Therefore in their slightly more realistic model (i.e. Noonworld plus CO2) of Venus they would get the wrong temperature and therefore their original model must be wrong.
IR active gases are also cooled by incident longwave radiation via stimulated emission so that the Laws of Thermodynamics and Momentum are not violated.
http://web.ihep.su/dbserv/compas/src/einstein17/eng.pdf
Furthermore, most of the atmosphere on Venus is in the form of clouds and supercritical fluids which do not absorb and emit like gases.
CO2 would absorb and re-radiate but would not trap any of it. It would try to distort the lapse rate slope set by mass and gravity but in the process would speed up convective overturning. The so called ‘extra’ energy would then be returned to the dark side surface almost immediately since every point in the overturning cycle is connected. Like spinning a wheel every part moves faster at the same time.
The faster loss of radiation to space from the dark side surface would neutralise any thermal effect from the CO2.
In our Noonworld schematics it would be a matter of adjusting some of the numbers to reflect the radiative opacity of the atmosphere.
Stephen,
If CO2 is absorbing and re-radiating then it will trap energy simply by the fact that half of that energy is directed towards the surface of the planet which will absorb it and heat up. Or does that not happen?
Also you have not shown in your analysis that large scale convection cells would be set up. Looking at your figure I can just as easily draw one where the air moves counterclockwise which is just as likely. These two flows would then cancel out leaving only diffusion on noonworld as a heat transport mechanism.
The response of a warmed CO2 molecule is first to rise upwards because it is warmer than its surroundings. Conduction to surrounding molecule will occur during that process and it will enter a region of lower density for a cooling effect so after a while it will settle at a height along the lapse rate slope appropriate to its temperature. As it goes higher it radiates more to space than to the ground because of the lower densities above. Convection juggles all out of position molecules until their thermal effect is neutralised. Any remaining energy surplus gets shifted into faster convective overturning which gets energy back to the surface on the dark side faster from where it is radiated to space sooner than would otherwise be the case so any potential thermal effect at the surface is neutralised but there would be a miniscule adjustment to climate zone positions instead.
Large scale convection cells are ubiquitous within every atmosphere and also within giant gas planets. They are even set up in the Earths mantle and within the sun.
I can’t envisage two flows running in opposite directions so as to cancel out. There will always be a planetwide configuration of some sort.
”[co2] will enter a region of lower density for a cooling effect so after a while it will settle at a height along the lapse rate slope appropriate to its temperature. As it goes higher it radiates more to space than to the ground because of the lower densities above.”
Most elegantly put. Thank you! It really cannot be any other way. Hopefully this will contribute in putting to death the dubious claims of the remaining luke warm radiation enthusiasts still looking for a signal they will never find.
Stephen,
The mean free path for an air molecule at room temperature and pressure is about 65 nm (https://www.sciencedirect.com/science/article/abs/pii/0021850288902194 ) so an excited CO2 molecule isn’t going anywhere before colliding with another molecule and transferring its energy. In addition the RMS speed of a molecule at room temperature is about 500 m/2 while the lifetime of the radiative transition for CO2 is about 1/2 second so a typical CO2 molecule might travel 250m before re-radiating during which time it will undergo about 1 billion collisions giving it plenty of chances to heat up the surrounding air.
This is completely false.
When CO₂ absorbs radiation, this excites a flexing vibration. It doesn’t affect the velocity of the molecule at all.
Then, almost immediately, the CO₂ molecule will collide with another gas molecule. This transfers the vibrational energy to another molecule, and restores CO₂ molecule to basically the same energy as everything around it. At that point, the mixed gas as a whole will have gotten incrementally warmer.
At no point is there any reason for the CO₂ molecule to preferentially rise.
There is no such thing as an “out of position molecule.”
Temperature is not a meaningful concept at the level of an individual molecule. And, even if a molecule had an atypical amount of energy, within a fraction of a second that would be remedied by it colliding with another molecule.
When CO₂ absorbs radiation, this excites a flexing vibration. It doesn’t affect the velocity of the molecule at all.
co2 is a small (very small) part of the air. Warmed air rises. All of it.
Agreed. I was disagreeing with the nuances of how Stephen was describing the process.
All other molecules that have been conductively warmed by the CO2 molecule would rise up with it because all would be ‘out of position’.
I was just trying to keep it simple
“Also you have not shown in your analysis that large scale convection cells would be set up. Looking at your figure I can just as easily draw one where the air moves counterclockwise which is just as likely. These two flows would then cancel out leaving only diffusion on Noonworld as a heat transport mechanism.”
Izaak,
The figure is for illustrative purposes, I tried to make it as fundamental as posssible. The air circulation pattern on Noonworld is a 3-dimensional torus.the ascended air aloft passes over and in the opposite direction to the return flow at ground level. This cellular airflow pattern is designed to mimic the stucture of the Trade Winds in a Hadley cell.
The net effect on the planet as a whole is zero. There is increased IR absorption and additional kinetic energy from incident radiation on the ascending current but stimulated emission and decreased kinetic energy from incident radiation on the descending current.
CERES net radiation balance shows it.
https://www.researchgate.net/publication/320918200_Measurement_of_the_Earth_Radiation_Budget_at_the_Top_of_the_Atmosphere-A_Review
The net effect is zero on the total energy within the system but the surface is warmer than without a convecting atmosphere.
What is the mechanism that you believe yields “the surface is warmer than without a convecting atmosphere.”?
As I understand it, convection could help smooth out temperature across the globe, with raises a planet closer to its effective radiating temperature (the S-B rate if the planet had a single temperature). But, aside from that, convection has a net cooling effect.
What mechanism would make this untrue?
Convection delays radiative emission to space for the period of time required for one global cycle of convective overturning. That involves an accumulation of energy in the system that would not otherwise occur so the surface temperature beneath the atmosphere must rise to enable provision of the energy required by continuing convection.
I think you’re thinking about energy in a way that is confusing you.
From a heat flow perspective, convection transports heat from somewhere warmer to somewhere colder.
That’s its net energetic effect. There are two types of destinations for convective heat flow in the atmosphere:
The first effect can reduce variations in global temperatures. This can produce some warming up to the point of the “vacuum planet” equilibrium temperature, Teff. But, it can’t produce warming of the sort attributed to the greenhouse effect, i.e., warming beyond Teff.
The second effect cools the surface. Period.
If you make your logic complicated enough, you can convince yourself of anything.
But simple thermodynamics says you can’t possibly be right on this.
We aren’t dealing with a heat flow scenario here.
We are dealing with a conversion of heat (KE) to not heat (PE) and back again within an energy (not a heat) flow.
As for heat transported upwards by convection it is not lost to space in so far as it is converted to PE since PE cannot radiate to space.
Adiabatic processes are fully reversible so the KE does indeed return to the surface in descent when the PE returns to KE.
My very first response points out that you omitted that conversion and reconversion process in your criticism of our work. I am puzzled that after reading through this thread you have still not realised your oversight.
Energy flow and heat flow are two separate perspectives one can use in analyzing a system.
Just because you prefer to work in the energy flow perspective does not remove the validity of an energy flow perspective. You can’t opt out of honoring thermodynamics.
Weather and climate are driven by energy input from the Sun and thermodynamic processes transferring heat between various parts of the system. There is also work done by and on packets of air as they ascend and descend.
None of this is out-of-bounds for thermodynamic analysis.
I omitted it because I’m afraid I continue to fail to see how it has the slightest relevance.
In Noonworld, in steady-state, X watts of heat are transmitted into the atmosphere on the Lit side. Because we are in steady-state, the same X watts are transmitted to the surface on the Dark side.
Details of convection can alter how large or small a value X is (subject to some limits).
But, nothing can change the fact that in steady-state the heat leaving the Lit side surface and the heat arriving at the Dark side surface must match.
It doesn’t matter that kinetic energy was converted to potential energy and back again. That in no way changes that equation.
Bob,
I think we are getting close to a fundamental feature of the diabatic Noonworld model, namely that it matches the Vacuum Planet equation. It does this with a flux partition ratio of β =1/2 for both the lit and unlit surfaces of the model.
A heat flow of X watts from the Lit side to the Dark side will bring the average temperature closer to what you’re calling the Vacuum Planet equation temperature (Teff, which gives radiative equilibrium assuming uniform temperature). Your model produces a vaguely similar result, but I’m pretty sure it achieves this by not conserving energy. I’ll need to check some details to verify that.
Bob,
Note that it is the diabatic model that matches the vacuum planet equation.
Once one then moves on to the adiabatic model then the enhanced surface temperature is observed.
In neither case is there any failure to conserve energy as long as you count PE as energy.
I appreciate the distinction, and I’d like to understand it more clearly.
Are you calling it “diabatic” when the partition ratio is equal everywhere? Or when it is 50:50?
And when is it “adiabatic”?
And why do you find these labels appropriate?
I’m guessing getting clear on this distinction could be quite helpful.
I think you should look it up but diabatic energy transfers involve the addition or removal of energy from the process and adiabatic does not.
The reason that the distinction is important here is that the uplift and descent of air within an atmosphere is adiabatic so that during the process no external energy is added or removed.
That means that during the process the radiative transfer of energy is halted which results in a build-up of stored energy within the system whilst the adiabatic process works through.
Therefore there is a delay in the throughput of radiation which inevitably results in a system temperature rise which we measure at the surface.
The surface temperature becomes higher than that predicted by solely radiative equations because a non radiative adiabatic process is interfering with the radiative flow through the system.
I’m familiar with the terms adiabatic and diabatic in general. I’m just not clear on how you are applying those terms in the context of your model and your reasoning.
When looking at your Noonworld paper, are you using a diabatic model for Noonworld and an adiabatic model for Venus?
If so, how would one discern this by looking at what you’ve done in your modeling?
Why would one model apply in some situation, while the other model applies in others?
I now see that you say in your paper that using an energy partitioning ratio where more than 50% of the flux goes into the atmosphere is what you are referring to as the “adiabatic” model. Sorry for not picking up on the earlier.
The overall gravitational PE of the atmosphere does not change in steady-state. So, PE provides zero net power (energy change per unit time) to the system.
So, it’s hard to see how it would factor into an overall accounting of energy conservation.
“I’m pretty sure it achieves this by not conserving energy.” Actually, I misstated that. Energy conservation may not be the problem, but something is thermodynamically “off” in the model. I’m still trying to sort out how to assess that properly.
Philip,
By way of a “heads up”, I believe I’ve gotten clear on one serious error in your Noonworld Venus analysis and another questionable bit.
The merely questionable bit is this: The model assumes only one side of the planet is lit and there is no rotation. So, in the absence of convective circulation, there would be an enormous temperature difference between the Lit side and the Dark side. Such an enormous temperature difference could drive strong convective circulation. However, the final state your model converges to is one in which the temperatures of the two sides of the planet are nearly identical. Given that the temperature differences are small, how do you justify the enormous amount of convection needed to transfer heat from the Lit side to the Dark side? Once the temperatures are so close, the winds should be very modest. What is accomplishing the enormous amounts of heat transfer that are posited?
As for the “serious error”… You calculate a “total global energy budget” by summing energy flows into each hemisphere, and then deducing temperature from that. However, the surface temperature must correspond to the “radiant loss to space” from the surface. The amount of thermal radiation emitted from the surface is 𝜀σTₛ⁴ where Tₛ is the surface temperature. The surface temperature and the energy radiated by the surface have this fixed relationship. You calculate that to correspond to a temperature of -3.5℃. Yet, you calculate the Average Global Air Temperature as 464℃ (via a calculation that isn’t in any way justifiable, I’m afraid). Even if that calculation were correct, how can the air be 464℃ and the surface be -3.5℃?
I’m wondering if you’re able to make any sense out of this for me?
Of course the heat leaving the lit side and the heat reaching the dark side must match at equilibrium. That is a given.
However, it takes time for the process of moving heat from the lit side to the dark side to occur via the KE to PE and PE to KE exchanges and that constitutes a delay in the transmission of radiative energy through the system.
So the surface temperature must rise above the S-B prediction.
In the absence of any such exchanges radiation from space comes in and goes straight out again with no delay and the S-B equation applies.
So those slower exchanges of energy are the direct cause of the greenhouse effect by introducing a delay.
Well, it takes time for the process of convection to move heat from the lit side to the dark side because it takes time for air to move. I still don’t see how the KE-PE interchanges have any relevance to the end-points of the process.
There are ways in which “delays” in energy movement can affect temperature, and ways in which it can’t. I’m still trying to figure out how to capture what distinguishes these cases. I don’t think your “delay” is of the type that one would expect to have any effect.
* * *
A few pedantic details:
Well it is pretty clear to most people how the KE in descent that doesn’t get radiated out to space due to continuing convection would have to be added to continuing insulation to produce a temperature rise. More energy in the system makes it hotter.
I’m getting to the point where I don’t think I can help you any further since we are going round in circles.
It is pretty clear to most people that:
1 unit of KE is converted to 1 unit of PE.
The 1 unit PE is converted back to 1 unit KE.
1/2 unit KE is converted to 1/2 unit radiative energy lost to space.
To get back the 1/2 unit KE so that the air can convect again 1/2 unit of energy must be taken from the surface on the lit side, which is cooling the surface on the lit side, and the average temperature is not raised.
This should be all the help you need.
You omit the effect on the unlit side. KE from descending air offsets part of the surface radiation to space so that the unlit surface never gets as cold as it otherwise would. Then the air flowing back to the lit side cannot cool the lit side as much as it otherwise would and both sides end up warmer.
No, I’m presenting a correct energy budget, in balance. Yours is creating energy.
Yes, the unlit side never gets as cold, but at the same time the lit side never gets as warm as it otherwise would, and the energy increase on the unlit side equals the energy decrease on the lit side (compared to noconvection), otherwise energy is created.
“otherwise energy is created”
lgl
The model is not creating energy, the model is storing energy.
What’s wrong with this energy budget (the convection part)?
Notice the profound correlation of air temperature with [CO2]_atm in this chart, Izaak.
Do point out the greenhouse effect, thanks.
Dr. Frank, Good point! If you have an opinion on the validity of the Wilde-Mulholland theory, I would very much like to hear what it is.
Thanks, Thomas. I’ve not studied it. And I’ve presently got so many fish to fry there’s unlikely to be time for it.
But I’m all in favor of analytical theorizing. Doing so a healthy development in a field — climate physics — that the climate modelers in their arrogance and incompetence have rendered moribund.
Also, please call me Pat. 🙂
You cannot ”trap” heat, and people that use that line are complete fukcwits.
You don’t know what heat is do you, not even the very basics.
Heat isn’t ”a thing” heat is the consequence of a thing, a thing called ”work”.
Heat is defined as the form of energy that is transferred across a boundary by virtue of a temperature difference or temperature gradient. Implied in this definition is the very important fact that a body never contains heat, but that heat is identified as heat only as it crosses the boundary. Thus, heat is a transient phenomenon.
Thermodynamics, G. J. V. Wylen, John Wiley & Sons, 1960
Co2 does not trap heat, nothing traps heat as heat only exists as a flow of energy.
Again, what? Lagrangian and Hamiltonian mechanics called, they’d like to be relevant in physics again.
So, is this diagram an energy flow diagram or a heat flux diagram? A subtle distinction (based on the loose use of heat in these circles). Dr. Wentworth maintains that “heat flux will only travel from hot to cold”, which is true. However, it is not obvious to me that this diagram is showing heat flux. If it is showing energy transport, then it is fine (kind of). If it is showing flux, then is it impossible? Bulk air flowing (even colder air), does transport energy. Convection can transport energy from a cold region to a warm region, as PV=nRT, PV is energy (as is nRT of course). We are dealing with ideal non-greenhouse gasses here. Approximately, for every unit mass of cold air returning we have an equal mass of air leaving. Both batches of air contain energy (PV, or nRT depending on whether we want to think of it as thermal or mechanical). Add them up and you get the flux.
Now, if they are thermal energy arrows, why is there 1 unit entering the system and 0.75 units leaving? I feel that I am missing something or there is a description of this system that I need to see.
Philip has answered that query above. The schematic used by Bob is out of context and only shows an intermediate scenario.
Please refer to our full Noonworld article from nearly two years ago.
https://wattsupwiththat.com/2019/06/02/modelling-the-climate-of-noonworld-a-new-look-at-venus/
Fred,
It is an energy flow diagram. The flux is carried by the specific heat capacity of the mobile fluid.
Ben has unfortunately posted the intermediate figure 2 derived from our original WUWT post. You need to look at either figure 3 in the original WUWT post, or figure 2 in our published paper to see the stable dynamic balance state.
Thanks
Some of this PE, KE, gravity theory sounds similar to Doug C’s theory.
Yes, I have communicated with Doug. His position is similar to that of the Connollys in that they are on the right track but lack the relevant mechanism. Doug resorts to a novel process involving diffusion and they use the term pervection.
Neither is necessary.
I would have thought noonworld would be like a sea breeze effect, just on a much more massive scale.
Stephen Wilde and Philip Mulholland, It’s a facsinating theory and it seems plausible to me. I would also like to say that I am impressed with how you have both conducted yourselves in this thread. No name calling, no snark, just cool, calm responses.
peterg,
You are quite correct.
Isaac Asimov discussed this idea in his short story Ribbon World.
See also the Morning Glory Cloud as another real world example of the sea breeze process.
If one looks careful at step #3 in the process described above, it involves cold air circulating to the hot side of the planet and then giving some of its heat to the hot surface. It involves heat flowing from cold to hot, violating the Second Law of Thermodynamics.
=====!??
Not correct. The sign of the flux would simply be negative, The heat would flow from the warm side to the cold returning air.
Depending upon rhe point of view of the math, you might add a negativr value or subtract a positive value.
For example, the flux to heat 1 liter of water 1C is 1 kcal. The flux to cool 1 liter of water 1C is not 0. It is 1 kcal, but in the opposite direction. It is heat removed rather rhan added.
I’ve learned more from this thread than many others together. Thanks to all involved.
Mike,
You’re welcome.
Meteorology is a fascinating part of the atmospheric sciences.
And the astrophysicists who took over climate science in the 1980s know virtually nothing about meteorology.
If one looks careful at step #3 in the process described above, it involves cold air circulating to the hot side of the planet and then giving some of its heat to the hot surface. It involves heat flowing from cold to hot, violating the Second Law of Thermodynamics.
======!=
I took a quick look at the math. The energy budget is as follows:
Energy in from sun 1 unit
Energy radiated from warm side to space 3/4 unit.
Energy tranferred from warm side to cold side 1/2 unit.
Energy radiated from cold side to space. 1/4 unit.
Energy transferred from cold side to warm side 1/4 unit.
The energy transferred from the cold side to the warm side is the additional energy accounted for in the additional 1/4 unit radiated to space from the warm side.
Everything appears to balance without any problems.
Note: because convection and conduction are linear and radiation is 4th power there are likely an infinite number of solutions to this problem that will give the “correct” answer.
The outgoing radiation on the warm side should be 3/4 units, then the energy budget balances.
Otherwise the warm side has 1.25 units of energy comming in and only 1 unit going out.
“The outgoing radiation on the warm side should be 3/4 units, then the energy budget balances.”
Ferdberple,
The figure 2 in the head post here is an intermediate step in the process of developing a dynamic equilibrium. Please look at Figure 3 in our original WUWT post here.
The dynamic balance for a diabatic (equipartition model) is 2/3 lost from the lit side, 1/3 lost from the dark side and constant unit of 1 retained in the atmospheric reservoir. This gives a balanced model total budget of 2 units.
Convection is a means of carrying a heat flux. Heat fluxes flow from hot to cold. Unlike radiation, they can’t ever recycle, building up power like radiation in a resonant cavity.
===!!!?!
There is nothing special about radiation. Neither radiation nor convection can change the direction of entropy.
Without cool air overlying rhe surface, the surface is exposed to the cold vacuum of space. Energy that would have been capture from the hot surfacw by the cool air is instead lost foreever to the vaccum.
However when the cool air captures the surface energy this energy cannot be radiated to space, unless ghg are present. Orherwise the now slightly warmer air is now available to heat cooler portions of the surface, or will be easier to heat further.
The critical item is that energy captured by the atmosphere would otherwise have been lost to space. And when this energy is either returned to the surface or to further enhance warming of the atmosphere, the energy must eventually warm rhe surface before it can be returned to space.
And it is precisely because a cold object cannot warm a hot object, that the energy in rhe atmosphere must accumulate until the temperature of the atmosphere is greater than the surface and thus warms the surface.
It seems to me that there is a tendancy with this discussion to drive into the weeds while igbnoring the elephant in the room. There are only three components to this system; earth, atmosphere, and sun. The sun supplies a constant source of energy via sw. The earth is the only thing that can shed this energy via LW. The atmosphere takes no part in expelling exccess energy to space. And, the outgoing LW flux MUST equal a constant equal to the incoming SW flux.
So given these constraints, no amount of upwelling, downwelling, evaporation, or condensation can chanmge that fundamental unless it is creating energy by virtue of gravity. The last time I checked, gravity is a force and the only way it does work is by moving something. The something it moves is atmosphere.
For gravity to contribute to a positive net gain of energy to the earth there must be a net displacement of mass inward.
All that KE to PE and back nets out to 0 or the atmospherre either compresses into a black hole or gets blown out to space, lost forever.
Lapse rates and rotation and high pressure, low pressure, corialis, and hand waving is just weather creating localized emergent conditions and can not possibly be making a net system energy gain.
Paul,
Our model is broadly in agreement with that save that one really does need additional KE at the surface if the atmosphere is to maintain an ongoing convective overturning circulation.
Apart from that the only relevant parameters are indeed insolation, atmospheric mass and the strength of the gravitational field as you appear to be suggesting.
Not really what I was suggesting. Your model is creating energy, net positive.
Where does it go, rhetorically of course? It has to go somewhere, right? It can’t leave unless it heats the earth which then radiates it away. This leaves you with a planet that radiates more energy to space than it receives. Ergo, the atmosphere is creating energy from a force, gravity, which means there has to be a net downward movement of mass. That can only happen for a geological instant, eh?
If the atmosphere is all tennis balls, and weather is tossing them all which ways, then every bit of ke that is converted to pe is exactly returned as ke for a net zero energy balance. Weather neither creates nor destroys energy. It just moves it around and absent ghg it can’t possibly change the planetary energy balance.
That’s an elephant your model neglects.
The up and down process introduces a delay in the flow of radiation through the system.
No extra energy created.
“Not really what I was suggesting. Your model is creating energy, net positive.”
Paul,
Our model is retaining energy not creating it. The retained energy is that portion of the energy which is left over from the previous cycle of mass motion overturn and kept in the air of the global Noonworld Hadley cell torus.
I asked the same question. Where does the added energy come from. My understanding of the greenhouse effects is that some LW radiation is sent back to the surface, which causes the surface to warm, so it radiates more, until the total balance between incoming radiation and outgoing radiation is restored.
On Noonworld heat is carried by convection from the hot to the cold side, and “cold” flows from the cold side to the hot side. The net result is a cooler hot side and a warmer cold side. The effect is to make the temperature more even but I don’t see where heat could have been added.
Why do the authors use a tidally-locked plant to demonstrate their theory, why not a rotating planet?
Locking the planet does provide a simplification, but for my money it is really irrelevant. It could be a chunk of blue cheese being eaten by a hord of alien rats. It just does not matter.
From an observer in space you have energy in that must equal energy out on a planet that is equilibrated. This model has gravity creating energy by alternating ke to pe and back again.
Smells a lot like perpeturanium to me.
Perpeturanium. Ha!
Smells that way to me too.
No extra energy created. Just a delay in the in/out radiative flow.
A bit like an eddy in a stream induced by the presence of a rock.
Is your model equilibrated? If yes then a delay is irrelevant. Integrate energies over, say 1000 years. Your delay disappears.
I’m struggling with how it would ever equilibrate, actually.
So if you aren’t creating net energy then you aren’t creating net temperature increase to the system, right?
Your ‘delay’ only matters for the first cycle through the system. By your own reckoning the delayed release equals the increase. Once equilibrated , the delayed energy release is just a scalar value with no temporal significance.
”On Noonworld heat is carried by convection from the hot to the cold side, and “cold” flows from the cold side to the hot side. The net result is a cooler hot side and a warmer cold side. The effect is to make the temperature more even but I don’t see where heat could have been added.”
Not sure what you mean here. Lit side is heated, (at a constant rate) warm air moves to the dark side, (at a constant rate) some is radiated away, (at a constant rate) some (warmed air) returns to the lit side making it slightly warmer than if all the energy was removed from the dark side before it returned. No extra heat added. That’s my understanding.
“No extra heat added. That’s my understanding.”
Mike,
You are quite correct. We are modelling the meteorological process of solar energy capture, fluid mass motion energy delivery, thermal radiant energy exhaust to space and the critical component of energy retention within the global circulation system of the mobile fluid.
“Why do the authors use a tidally-locked planet to demonstrate their theory, why not a rotating planet?”
Thomas,
Your question goes to the heart of what we are trying to demonstrate, namely that it is the meteorological process of mass motion of air that carries energy across the surface of a planet, and not the astronomical process of diurnal rotation.
How so? Well, we can all agree that the Earth rotates every day from west to east and so it must be that process of diurnal rotation that carries the energy to the night side.
Correct? Well no.
Let me ask you this question. What is the planetary rotation mechanism that each day carries the intercepted sun’s energy from the equator to the north and south poles?
Clearly that is a strange question, it is the equator to the north/south pole and back again meridional movement of air that carries the energy across the surface of the Earth from the equator to each hemisphere’s pole of rotation. Put simply it is meteorology that we are studying here and not planetary diurnal rotation. So let us discard the process of diurnal rotation and start our study with a tidally locked planet, one where the only possible mechanism for the transport of energy (in both the zonal and also meridional directions) is the meteorological movement of air across the surface of this globe.
Thank you for a very challenging question, that first required a good night’s sleep for me to be able to properly address your concern.
Thanks Philip. So is the theory that turbulent convection somehow slows the loss of heat, reslting a plant that is warmer than it would otherwise be? If so, how does that mechanism work?
“If so, how does that mechanism work? ”
Thermal capacity and residence time.
Ah, so the only way the air can lose heat is by conduction with the ground. Air in contact with the hot ground rises, which cause a lower pressure, which suctions air from the cold side, so the warm air sinks back on the cold side. Now the air flowing from the cold side is hotter and eventually a new equilibrium is reached where the total atmosphere is hotter than it otherwise would be.
But are you implying that there is no radiative greenhouse effect in Earth’s atmosphere, or just that this Wilde Effect (ha!) could also play a part in keeping the Earth warmer than it would otherwise be?
Is the convection on Noonworld just a consequence of the fact that it’s tidally locked? Roy Spencer seems to think there would not be significant convection on earth if there were no greenhouse gasses to cool the upper atmosphere. He thinks the atmosphere would expand a bit on the day side and contract a bit on the night side but otherwise not move around much.
https://www.drroyspencer.com/2009/12/what-if-there-was-no-greenhouse-effect/
In the real world the ground and ocean heat at different rates, and bare ground heats faster than ground with vegetation, etc. So I would expect some advection to occur.
I think a lot of people underestimate the mass and pressure of the total atmosphere. After all, everything that ever was has evolved under similar conditions. We live in it, it’s always there, so it’s almost like it doesn’t exist.. However, in reality we live under immense pressure at the surface. Solar input provides substantial power to lift the tropospheric mass in pressurized convective overturning circulation. High pressure mass fluid dynamics result in turbulent eddies at all scales and altitudes. Add in coriolis effects and circumpolar vortices. All this can be simplified by observed long term averages in the form of Hadley, Ferrel, and Polar cells. Energy is along for the ride under the engine of sun and gravity in fluid mass. A hypothesis is that the fluid mass movement turbulence provides a net energy recirculation mechanism of some magnitude. Total inputs = total outputs to the system in this scenario, + the turbulent circulation factor. All this means is that the existence of the atmosphere itself makes energy stick around a bit longer than it otherwise would while circling around. Everything else is the result of this high pressure air circulation. From the temperature we feel to the existence of liquid water to latent heat effects and the long-wave radiant energy observed. For me, to remember the existence of the atmosphere I tend to think of the wind as suction instead of a pushing force. A pressure head. For me personally this perspective helps me remember the interconnected nature of all mass flow in the atmosphere and the immense expression of simple forces. The atmosphere is so much more than passive radiative effects. JCM
JCM
Thanks for your efforts in this thread.
The ”down ticks” on some of the comments in this thread shows just how meaningless they are.
The meaning is that there are many out there who simply don’t accept reality or science and automatically tick down anything that does not suit their preferred world view.
For those concerned about heat flowing from the cold region to the hot, I think the graphic is somewhat misleading. Think of it this way. Set standard enthalpy at zero units. The air flowing from hot to cold has 75 units of enthalphy. The air flowing from cold to hot has 25 units of enthalpy. So it’s more of an enthalpy balance. No problem with that.
As far as convection, the KE/PE, reducing entropy talk is rubbish. Basically the unlit side would develop high pressure at the surface, and the lit side would develop low pressure. This due to density changes in the columns of air. The pressure gradient would drive the convection.
For those talking about lapse rate, keep in mind that lapse rate is resultant. If you had a planet that is 100% reflective with a transparent atmosphere, your lapse rate would be zero and the atmosphere sampled anywhere would have the same temperature as the surface.
In his comments Bob Wentworth asserts that an atmosphere with a temperature fall at a rate lower than the adiabatic lapse rate is stable.
That is not correct and may be part of his difficulty.
Any decline in temperature with height will result in convection.
Stable air only arises in the absence of or reversal of the usual temperature decline with height.
Under descending air in a high pressure cell it is the release of KE from PE during the descent that keeps the descending column persistently warmer than the surrounding air thus reversing the lapse rate slope and suppressing convection.
Note too that our thesis relies not on the dry adiabatic lapse rate but rather a lapse rate dependent upon the decline in density with height which is likely to be different to any of the usual observed lapse rates.
People should also note that during the course of his contributions Bob has repeatedly accepted errors and has adjusted his position but in my humble opinion he has not yet eliminated all his errors.
The concept of stability being tied to the lapse rate is fine in theory but due to temperature and density differences in the horizontal plane the decline with height will always be either faster or less fast than the adiabatic rate.
So, in practice those horizontal differences control the actual outcome and not the lapse rate itself.
The slightest horizontal temperature variation will tip the atmosphere into stability or instability.
Therefore it is misleading to suggest that the adiabatic lapse rate itself governs stability or instability. It is the unevenness of surface heating that really matters and that can never be eliminated which is why our model works with a perfectly transparent atmosphere.
Thus an atmosphere declining at the adiabatic rate is only conditionally stable and that stability can be overridden by the smallest Temperature variations in the horizontal plane.
To be fair to Bob the standard texts are highly misleading in that the various lapse rates all have a temperature decline with height but none of them are ever maintained consistently to any great height or for any great length of time so using them to determine stability or instability has no practical utility.
Bob was led to thinking that an atmosphere with a lapse rate would be stable if the lapse rate were maintained. That is true in logic but not reality because it can never be maintained and so no useful diagnosis of stability or instability can be derived from it.
What really matters is the ability of horizontal variations to switch the local atmosphere between stable or unstable with the tiniest of adjustments.
Yet another point is that it is being assumed that stability means static.
It doesn’t.
It means an absence of uplift.
An absence of uplift means the presence of descent and it is the tendency to descend that blocks uplift.
Except for rare short lived localised inversions stable air is always descending as a result of uplift elsewhere.
My father used to tell me, son you can’t see the the forest because the trees are in the way… it also helps if you pull your underwear off your head.
I’ve read through your comments on this “noon world” subject and it appears that you’re all just spinning your wheels.
Mercury receives 800°F raw unfiltered Energy (heat and light) from the sun, Venus receives less energy through 92 earth atmospheres. And yet, Venus is hotter than mercury. Venus, at 860°F emits more energy than it receives from the sun. This is not possible unless it has its own heat source.
So does Jupiter, Saturn, and Neptune. Uranus emits the least of the thermal red radiation in this order because it has a less dense atmosphere than the others. Under its atmosphere it is close to 9500°F at the bottom of the air column, about the same temperature as the surface of the sun (photosphere). The other gas giants are hotter than the suns photosphere.
If you’re looking at the sun as the source of all heat, you’re obviously looking in the wrong direction. The suns influence on the gas giants is minimal, and yet they are incredibly hot. Jupiter is so hot beneath its atmosphere there is a layer thats literally “plasma” with electrons forming a current so strong that it’s atmosphere gives Jupiter it’s extremely strong magnetic field.
Your article references A hot and cold side of noon world… Venus averages 860°F on both sides. The only difference in temperature regardless of the position of the sun is in altitude. Mountain tops are closer to 800° while craters and Canyons, the deepest parts of Venus, are near 900°. There is a steady decrease in temperature the higher you ascend through the atmosphere. The top of Venus’s atmosphere has been measured over 200° below zero, “dry ice crystals”form making it colder than anywhere on earth. For the suns energy to penetrate the upper layer to heat the lower layer, this cold region cannot exist, violation of the laws of thermodynamics.
I do not know what causes the winds on Venus to circle the planet every two days. I suspect it’s electrical in nature, a thermal pile effect. Just like your pilot light in your heater at home. Conduction from hot to cold causes an electrical current, an extreme case is evident on the sun causing nano flares that follow the path of least resistance, electrifying the chromosphere were all the suns light, heat, and solar wind emanate from. An electrical current flowing inside a magnetic field will cause air and fluid to spin. (Venus does not have a magnetic field but it is very close to the suns)
There is a better example for your illustration that has sunlight/darkness for a longer period than Venus.
Earths poles.
For example, Antarctica winter is six months long with no sunlight whatsoever. It averages -70° F. That’s 230° warmer then the cold of space a few miles above it (-300°F). That’s right, Antarctica emits heat all winter.
In the summer, it receives partial sunlight until the peak summer months where the sun circles the sky but never sets. With more than three months of continuous sunlight you would think Antarctica should be the hottest place on earth…
The temperature averages -40°F, only 30° warmer than winter. Plug that into your model and smoke it!
The north pole receives the same amount of solar radiation. It’s average temperatures are much warmer… Why?
It is at sea level. Antarctica averages over 10,000 feet altitude make it the top of the mountain. Everyone knows higher elevations equals cooler temperatures. Always.
Mount Everest will always be colder than death Valley because of the air pressure at lower altitude. More air pressure generates more friction resulting in heat. This friction is being generated continuously, from the top of the atmosphere to the bottom, becoming warmer the deeper into the atmosphere you go. No circulation required. (although wind generates more heat drying things out faster, raising the temperature before a storm arrives)
The only exception is UV rays which are absorbed in the upper atmosphere generating heat, that it’s not measured at lower altitudes, while breaking apart air molecules forming Ozone. At night this does not occur, and the temperature drops without exception all the way to space.
That’s why the heat is always greatest at the lowest altitude, the surface. When the chinook winds blow down from the Sierra Mountains, the air heats up 5.4°F for every thousand feet the air descends creating the Nevada desert, this heating occurs whether the sun is up or not. (In fact the chinook winds holds the worlds record for fastest/largest change in temperature… You don’t see that in any of the climate models!)
I should mention that the earth emits more heat than it gets from the sun. I’m not a scientist like you guys are, but I can do simple math. Average temperature on earth is near 50°F.
The moon in the same orbit as the earth is 250°F on the equator in the sunlight. -300°F on the night side. That means the Moons mean temperature, without an atmosphere to reduce the energy input, is -50°F!, 100° colder on average than the earth.
how much energy in the form of heat does the sun give us? Take the low of the night and subtract it from the high of the day. The difference is the total amount.
Wow!! How did I miss this??
These guys have nailed it!!!!!
Since it is not our diagram I’m unsure whether that is sarcasm.