Why potential temperature increases with height

Note that the isentropes are spaced further apart within the warmer airmass. This is an indication of lower static stability. A cross section of a warm front shares similar characteristics. A warmer, southern airmass and a cooler, northern airmass, with a tightly packed area of isentropes in between, as seen in the lower left of this cross section from Bancroft, Ontario to Tallahassee, FL. Here is another example - see if you can identify the airmasses by their temperature, the main frontal zone, and the tropopause.

Drag the appropriate labels onto the cross-section to indicate where each airmass, the frontal boundary and tropopause exists.

Much like the previous examples, cold air exists to the west, warm air exists to the east, and the tightly packed isentropes indicate the cold frontal boundary between the two airmasses. The tropopause is discernable just below the area at upper left, in which the isentropes become very densely spaced above about mb. It quickly extends eastward and upward off the page above mb. Cross sections of potential temperature or equivalent potential temperature can also reveal the structure of jets and tropopause folds, as in this conceptual diagram:.

While we will not add isentropic potential vorticity in this lab, we can notice the placement of the polar front jet above relative to the front itself. Unfortunately, bulk kinetic motion of the atmosphere wind is usually driven by pressure gradients rather than by temperature gradients.

Of course it does. Think about it. That pressure gradient causes air flow. Coriolis force deflects the flow and eventually you get the jet streams. I have enjoyed the post and the thread discussion over the past weeks. I think I read your own lament on your blog a little while ago that your time is very limited for blogging.

During strong convection, driven by latent heat release, a large portion of that latent heat release is converted into PV work expansion rather than thermal energy. And a higher ratio will result in a stronger upward convection PV work and a higher maximum convective height. More latent heat is converted into gravitational potential energy height rather than thermal energy temperature.

This is an example of non-equilibrium thermodynamics at its best. The excess pdV term beyond equilibrium is the missing energy source you are looking for. They are both calculated assuming thermodynamic equilibrium conditions CpT for thermal energy. This is due to the continued buoyancy which is causing a steady increase in gdh. The pdV component is exhausted. Maximum convective height also increases as surface humidity increases.

You can see this effect from another perspective in my figures 3 — 5. The difference between this theoretical profile and the actual temperature profile represents the excess pdV expansion work that is occurring.

It is worth noting that this phenomenon may explain the missing hot spot that many climate scientists are frantically searching for. You say:. Hi Cohenite; Good to hear from you. I think the models do not properly take into account the fact that the latent heat of condensation is dispersed both as heat and PV work.

The actual thermodynamic behavior within the troposphere is not just a heat transfer mechanism, but a combined heat and mass transfer phenomena. He believed that the models assumed a constant equivalent potential temperature with altitude but was not able to confirm it. I have asked the question to several people, including Will Happer at Princeton, but I have not gotten an answer. There seems to be a dearth of actual model knowledge out there — which is scary since the entire academic field of climate science is based on these things.

They are very illuminating. There seems to be a dearth of actual model knowledge out there — which is scary since the entire academic field of climate science is based on these things.. An undiscovered tool of many people who strangely call themselves skeptics is called Google Scholar.

Google Scholar provides papers which reveals a laughable wealth of actual model knowledge. An embarrassment of riches. A veritable treasure trove of learned information. Google with the search phrase:. A good and more readable summary of an earlier version of CAM is in The Formulation and Atmospheric Simulation of the Community Atmosphere Model Version 3 CAM3 by Collins et al, Journal of Climate but seems to be behind a paywall, happy to email a copy to anyone, email me at scienceofdoom you know what goes here gmail.

Assuming constant equivalent potential temperature would be pretty strange for climate models given what they actually calculate. An hour or two spent reading papers, even a few minutes probably, would dispel that illusion for anyone.

Now that you have studied the models, how do they handle the allocation of latent heat of condensation between heat and PV work in a dynamic atmosphere? That is the question I have been asking.

I look forward to your answer. But, at the end of the day, or lapse rate, the models emphatically predicted a THS, which is yet to appear. I only ask as now one has ever placed an Energy Budget and atmospheric temperature profile side-by-side, with connecting arrows or photon fluxes on the stratified atmospheric profile. All of the atmosphere radiates. If you take one thin layer of the atmosphere it radiates equally in all directions, which means the up and down emissions are the same.

The reason why the emission upwards from the top of the atmosphere is much lower than the emission downwards from the atmosphere to the surface is the absorption and reemission that takes place through the atmosphere. The results are different in different locations, dates and times.

The emission and absorption depend on the concentration of various gases, especially water vapor and the temperature profile through the atmosphere. But for real life you need the results of a GCM. A more interesting result is the graph of heating and cooling rates vs height for different gases and in total.

Given the much lower concentration of absorbers going up, the path to freedom is much shorter than the path to the surface. Which one would, a prior, believe would have the flux gradient in the opposite direction. The number of absorbers from the surface to TOA is the same no matter which direction you travel in. The atmosphere near the surface is hotter than the atmosphere at the tropopause.

Therefore the emitted flux is higher near the surface than at TOA. If there was no absorption — for example if there was only a thin layer of atmosphere at one temperature, then the flux into space would be the same as the flux to the surface.

But the atmosphere close to the surface — the hottest level — emits directly to the surface with no absorption. The upward flux from this lowest level of the atmosphere gets mostly absorbed before it makes it to TOA. An internal study by the U. EPA completed by Dr. One statement in the executive summary stated that a paper found that the crucial assumption in the Greenhouse Climate Models GCM used by the IPCC concerning a strong positive feedback from water vapor is not supported by empirical evidence and that the feedback is actually negative.

Water vapor in the atmosphere causes a cooling effect, not a warming one. EPA tried to bury the report. The administrator Lisa Jackson and the administration have decided to move forward on endangerment, and your comments do not help the legal or policy case for this decision. I can only see one impact of your comments given where we are in the process, and that would be a very negative impact on our office. Yet this study had its basis in three prior reports by Carlin two in and one in that were accepted.

Another government cover-up, just what the United States does not need. Graham, what are you smoking? If they do not, then what do you propose is creating this nice warm troposphere that allows Important People to go out in shorts and golf times a week? Yes, I know this is a drive by. If you look at Solar Radiation absorption graphics you will see that water vapor absorbs quite a lot of incoming solar radiation and then re-emits the energy straight back to space, thus preventing the surface getting as warm as it would otherwise have done during the day.

Even carbon dioxide absorbs some incident solar radiation around 2 microns. The only effect that radiation from a cooler atmosphere can have is to slow the radiative component of surface cooling.

There cannot be any actual transfer of heat to the surface, though. Radiative cooling of the surface excluding that which goes direct to space is less than a third of total surface cooling. Evaporation and sensible heat transfer account for most of the rest. These non-radiative cooling processes cannot be affected by radiation from the cooler atmosphere because there can be no heat transfer from the cooler atmosphere to the warmer surface as such would violate the Second Law of Thermodynamics.

So, as I said, all that such radiation can do is slow the rate of cooling. It does so by supplying electromagnetic energy, not thermal energy. Hence the surface does not have to convert some of its own thermal energy to electromagnetic energy when emitting its quota of radiation. The important thing to remember is that the energy in the radiation is not converted to thermal energy in the surface. So other rates of non-radiative cooling cannot be affected. Now, if carbon dioxide does have even just this minuscule effect on the rate of radiative surface cooling, then a wider temperature gap would open up and consequently non-radiative processes would speed up to compensate.

So the overall net effect of carbon dioxide on the cooling rate of the surface would be nothing at all. Meanwhile, it and water vapor will have a slight cooling effect as they absorb incident solar radiation, as explained above. Please supply your equations for radiative transfer along with your method of calculation, assumptions, and final results. Any handwaving arguments about the effects of more or less of this or that constituent are handwaving arguments and not physics.

I might theorize that getting the space shuttle to the moon would be more fuel efficient if they just started a little bit to the left, used less rocket fuel and it would all work out better. Hey wait. How does a slowing of the cooling rate not create a warming trend? Oh, and how does the water vapor, with a residence time of about nine days, keep from pretty much condensing out of the atmosphere in your model—esp during ice ages?

Oh, and how does your model match up to the findings of Puckrin et al. Based on actual measurements, Puckrin seems to have found that CO2 can be quite a significant factor in radiative flux, particularly when it shares the atmosphere with H At any rate, you should probably have a look around this site.

If I were to refer you to the publications which contain the equations and the graphics supporting them, you would merely launch into criticism of the people involved, rather than discuss the physics. Your own equations are incorrect because, as in the Backradiation series, you assume that if radiation is not reflected or transmitted then it must be absorbed. In other words, you assume there is a heat transfer. But there can be no heat transfer due to one-way spontaneous radiation from a cooler atmospheric source to a warmer surface because total entropy would decrease in such a process.

Any subsequent returning radiation is irrelevant, and that component absorbed by the atmosphere may be less anyway when other sensible heat transfers also operate and some radiation goes to space anyway. Try applying your equations to blocks of ice receiving intense radiation in your microwave oven. Work out how quickly they should warm and melt.

Then observe what really happens. Absorptivity is not only a function of the wavelength of the radiation — it is also a function of the temperature of the receiving body.

Unfortunately not enough empirical work has been done on this, but no one has ever proved that backradiation actually causes a measurable heat transfer to a warmer surface.

Yes it can slow the component of cooling which is due to that component of radiation which is not going directly to space. But water vapor is hundreds of times more effective in total than carbon dioxide, based on its wider bands of frequencies and greater abundance in the atmosphere.

That fact alone puts carbon dioxide in its place. And nowhere do you even discuss my key point that water vapor and even carbon dioxide send some of the incident solar radiation back to space before it even gets to the surface.

They also help to radiate away the thermal energy which oxygen and nitrogen first acquired from the surface by sensible heat transfer. Where are your own equations regarding these cooling effects? When I first started studying atmospheric physics, I too was originally bluffed by the GH hoax. Then I became skeptical. Now I am no longer just skeptical, I am absolutely certain that carbon dioxide and water vapor have a very slight net cooling effect.

Natural long and short term cycles can and do explain absolutely all climate change. I will not be returning here, as no one here has an open mind to the facts. If you had read a textbook on atmospheric radiation you would realize that all of your amazing discoveries were questions already answered or confusion about basics on your own part.

A fabulous start to your treatise. I will let my record of articles on this blog speak for itself. In a two body problem the second law of thermodynamics tells us that both bodies move towards a common temperature. That is, the hotter body cools down and the cooler body warms up. In The Three Body Problem I proved that a warmer atmosphere increases the temperature of the earth compared with the case of a colder atmosphere.

And the entropy calculations are there for replication — in both cases entropy increases which means the second law of thermodynamics is not violated. Of course there is a third possibility, embarrassed silence. I consider that highly unlikely of course, not even worth considering and chide myself for mentioning it.

And just to absolutely clarify yet again, if the sun turned off then after a very very long time the sun, the earth and the atmosphere would all end up at the same temperature in a 3 body problem, i. The analyses of the changes in CO2 and other trace gases do of course include the absorption and scattering of solar radiation by these gases.

My equations are in the post I pointed you to earlier. The equations are not solvable analytically means no solution in the form of an equation — they must be solved numerically for different cases. As before — I have provided equations and their derivation from first principles. These equations have been well established for more than 60 years. I have also shown solutions in various posts on this blog.

You have provided no equations but made handwaving claims. Provide your equations. Wrong again, my friend. The energy in radiation from a cooler source is never converted to thermal energy in a warmer recipient.

I carefully explained a one way radiation scenario which had no dependent subsequent reverse radiation that was greater in magnitude. Yet with hand-waving you twist it into a standard two body scenario with simultaneous radiation and no other sensible heat transfer — theoretically. Every one way process must satisfy the 2LoT, except where there is dependency. You say the atmosphere warms the surface. Wrong again. At the most it might slow the radiative cooling process, but that does not stop the other cooling processes accelerating.

It is you who needs to prove otherwise. These are wrong. You continue to ignore the fact that water vapor has a far greater influence on such radiative cooling than does carbon dioxide, because the effect depends on emissivity and carbon dioxide cannot possibly have anything but very low emissivity because it radiates in very limited frequencies which are not at their maximum at most levels in the troposphere and stratosphere — only in the upper mesosphere around to C.

You are stumped on this one because you refuse to admit that radiation with frequencies lower than those being emitted by the target does not get absorbed in the sense that its energy is converted to thermal energy. Any such conversion in such a one-way radiation process would indeed violate the 2LoT and so does not happen. But the heat transfer is only associated with and caused by the radiation from hot to cold.

Not any of the heat transfer depends on the radiation from cold to hot. The result is no different whether that radiation is more or less than the radiation from hot to cold, as can be the case in the real world. All that matters is the relative temperatures and the emissivity of the hot body and the absorptivity of the cold body.

Absorptivity becomes zero when the source of the spontaneous radiation is cooler than the target. I await your computations of what you think the radiation in a microwave oven ought to do to ice cubes in, say, 90 seconds. Your equations were very compelling, but I might be more convinced I you would add some more poetic descriptions of what your equations signify….

Second, the intensity of microwave radiation from incoming solar radiation is infinitesimal compared to a microwave oven.

Third, microwave radiation is not absorbed by atoms but by molecules. Finally, the absorptivity of 2. Plastics, not so much. Water, very high. You misunderstand me, De Witt. I was not meaning just microwave radiation from the Sun, which is of course infinitesimal. I meant SW radiation.

The surface acts in the way which Prof Claes Johnson describes in the quote in my comment below. I am only discussing atomic level absorption which also leads to conversion of electromagnetic energy to thermal energy KE if you wish. When whole water molecules in a MW oven are rotated once with each wave of radiation and thus generate frictional heat that is a totally different process, which is unique to water molecules and a few fat and sugar molecules at MW oven frequencies.

It depends how you define absorptivity. Frictional heat generated at the molecular level is a totally different process which happens only within narrow bands which resonate with the natural physical frequencies of those whole molecules. There is absolutely no atomic-level absorption with conversion to thermal energy in any matter whatsoever receiving radiation in a microwave oven, when such matter obviously has a temperature above 1K.

There is an exact analogy with low frequency radiation from the atmosphere. Its energy is not converted to thermal energy in a warmer surface. Instead it supplies EM energy for the surface to do some of its own radiating. This EM energy never gets converted to KE because it is re-emitted immediately — just as quickly as reflected radiation, though the processes are different. None of its energy gets converted to thermal energy. The IPCC thinks it does and thinks it thus raises the surface temperature so the surface radiates more.

But the extra radiation does not come from surface thermal energy — instead its energy comes from EM radiation from the atmosphere which never got converted to thermal energy. Only a small portion of the radiation from the surface is actually transferring energy that was converted to EM energy from thermal energy that was in the surface. This portion does some of the surface cooling. More than half the thermal energy transferring from the surface to the atmosphere does so by non-radiative processes.

If this were not the case then there is no way that the ground-level air below 2m which is what we measure for climate would stay as warm as it does.

Radiation could not have this effect. But molecular collisions at the surface do have this effect. Radiation from the atmosphere cannot have any effect on the rate of these non-radiative cooling processes. If radiatve cooling were slowed by a very small amount due to radiation from carbon dioxide, then a wider temperature gap would open up between the surface and ground level air.

Thus, according to well known physics, conduction and evaporation rates would increase. This compensating increase has not been considered in IPCC models. SoD thinks this is accounted for in an adjustment to LW radiation. But that is inappropriate. There is no reason why the downwelling radiation from the atmosphere should be shown as being more than the upwelling radiation to space, especially when you consider the incident solar radiation captured in the upper atmosphere right up to and including the thermosphere..

Despite my best efforts, some continue to confuse themselves regarding HEAT transfer in a two way radiative exchange. This is wrong, but understandable, if someone is in a muddle about what exactly the difference is between heat, energy, work and radiation. However; 1. There is a two way radiative exchange 2. There is a two way energy exchange 3. But there is only a one way heat transfer. Carnot and Clausius were practical men who thought about the most efficient way to extract work from a heat engine.

They found that work such as a moving piston output can only be obtained with a high temperature source and a low temperature sink. For a complete cycle extract thermal energy from a higher temperature source do work then dump unused energy to lower temperature sink. From colder to hotter object, spontaneously extract thermal energy do work and dump unused energy to higher temperature sink. This never happens. Graham you see that you can test as to whether an energy transfer can be described as a heat transfer.

The transfer must be capable of doing thermodynamic work in the given situation Its clear then that heat is a Macro Quantity. The question as to whether or not a molecule absorbs a photon is a Micro phenomena.

There is a two way radiative exchange which you say is impossible. This is despite such an exchange being standard physics for over one hundred years. There is a two way energy exchange if the hotter surface absorbs ANY radiation from the colder object.

We are both in agreement that B can accept a 10um photon from C. However you think that B will reject an identical 10um photon from A. The temperature of the blackbody determines a cut-off frequency for the emission, which increases linearly with the temperature: The warmer the blackbody is, the higher frequencies it can and will emit.

Thus only frequencies below cut-off are emitted, while all frequencies are being absorbed. A blackbody thus can be seen as a system of resonators with different eigen-frequencies which are excited by incoming radiation and then emit radiation. An ideal blackbody absorbs all incoming radiation and re-emits all absorbed radiation below cut-off. Conservation of energy requires absorbed frequencies above cut-off to be stored in some form, more precisely as heat energy thus increasing the temperature of the blackbody.

As a transformer of radiation a blackbody thus acts in a very simple way: it absorbs all radiation, emits absorbed frequencies below cut-off, and uses absorbed frequencies above cut-off to increase its temperature. A blackbody thus acts as a semi-conductor transmitting only frequencies below cut-off, and grinding coherent frequencies above cut-off into heat in the form of incoherent high-frequency noise.

We here distinguish between coherent organized electromagnetic waves of different frequencies in the form of radiation or light, and incoherent high-frequency vibrations or noise, perceived as heat. A blackbody thus absorbs and emits frequencies below cut-off without getting warmer, while absorbed frequencies above cut-off are not emitted but are instead stored as heat energy increasing the temperature.

A blackbody is thus like a high-pass filter, which re-emits frequencies below a cut-off frequency while capturing frequencies above cut-off as heat. And if his theory is correct, he has overturned the last years of physics — as far as quantum mechanics and statistical thermodynamics is concerned. Which is quite a lot. However, this blog is based on standard science and the Etiquette of this blog states:. Basic Science is Accepted — This blog accepts the standard field of physics as proven.

Arguments which depend on overturning standard physics, e. The moderator reserves the right to just capriciously delete comments which use as their premise that standard textbook physics is plain wrong. This is aimed to reduce the continual stream of unscientific rubbish that gets placed here as comments. Future comments promoting the demolition of modern physics, entertainingly bad though they may be, will probably be deleted.

This happens because the Planck curve for a cooler body is always beneath and fully contained by the Planck curve for a warmer body. Hence the heat transfer is caused only by that radiation represented by the area between the Planck curves. This is not new physics — engineers have been using this calculation for decades when they subtract the two S-B calculations to get the difference.

Clausius stated the 2LoT in and it has never been disproved. After all, what could happen to that radiation which is neither reflected nor transmitted by ice cubes in a MW oven?. It is you , SoD who is making up an imaginary 2LoT which you say permits a heat transfer from cold to hot just so long as there is also a greater heat flow by radiation from hot to cold.

It is the IPCC who fail to explain why the air just above the ground is kept warm. After all, if it were then it would be far colder when relative humidity is low on a hot summer day. So maybe you can tell me just how and why carbon dioxide is supposed to cause the surface to warm and somehow have a significant effect not in any way dominated by big brother, water vapor?

And have that effect in the first two meters of the air just above the ground. But if you agree that only the radiative component of surface cooling can be affected, and that effect is far less than the effect of water vapor, and even when the radiative cooling is reduced, You say It absorbs 10um radiation from C while simultaneously rejecting 10um radiation from A.

Apparently encoded information about the Planck curve is carried by the photon. Have you any evidence for this? Some engineers use a subtractive short cut to quickly solve problems. If you ask any who had studied thermodynamics they would agree that real objects that emit 10um radiation will also absorb it regardless of its temperature source.

Yes, Bryan, Body B can handle all the 10 micron radiation from the cooler A, but there is more 10um radiation from the warmer C than it can handle. It resonates thus scatters the surplus 10 micron radiation up to the intensity for such on its own Planck curve. But that is all it can re-radiate because the Planck curve represents the maximum at each frequency, being, after all, that for a true BB.

So the excess radiation that is represented by the extra intensity which is between the Planck curves is what does the warming. Nothing else ever warms anything. All are very much aware that AGW is a hoax. KL only applies in certain circumstances. And, for much shorter wavelengths it re-emits virtually nothing at those wavelengths compared with what it absorbs. Why, because that is the radiation which, as explained by Claes in the quoted paragraphs above is having its energy converted to thermal energy in the surface.

It will surprise you to learn that Solar radiation also supplies direct EM energy for nearly all the radiation coming from the surface when it is actually shining on the surface. So the surface is not actually using its own thermal energy for what it is radiating during sunlit hours.

Rather there is pseudo scattering of a small part of the lower frequencies of the incident solar radiation. However, it is there and it does resonate with the surface. As far as energy is concerned, it is just as if all this small percentage of the total solar radiation is reflected back into the atmosphere, along with the downwelling IR radiation from the atmosphere itself.

It slows the rate of radiative cooling of the surface, but it does not actually add to the thermal energy in the surface. So most of the radiation from the surface which is lit by the Sun is not actually cooling the surface, just like when light is reflected by a mirror it is neither warming nor cooling the mirror.

Seeing that evaporative cooling is compensated for by precipitation, by far the majority of the heat transfer from the surface to the first 2 meters of the atmosphere is by physical conduction processes during molecular collisions at the interface. This is why and how the air temperature is maintained close to that of the surface, though usually just 1 to 4 degrees cooler in calm conditions. You are right, though Bryan, in pointing out that engineers take short cuts in assuming two-way heat transfer or, as you put it, that radiation is heat.

Maybe some readers are starting to understand why the simplistic, flat Earth IPCC models are as far from reality as was flat Earth science. It is you, SoD who is making up an imaginary 2LoT which you say permits a heat transfer from cold to hot just so long as there is also a greater heat flow by radiation from hot to cold..

Have a read of Amazing Things we Find in Textbooks — The Real Second Law of Thermodynamics where extracts from six heat transfer textbooks demonstrate exactly that point. After all, if it were then it would be far colder when relative humidity is low on a hot summer day.. Basic atmospheric physics textbooks will give you the insights you need into why all this happens.

You appear to enjoy inventing ideas and putting them into the mouths or pens of others. But the random mix of ideas you present to debunk has no relationship to anything claimed in atmospheric physics textbooks. Earth Science Stack Exchange is a question and answer site for those interested in the geology, meteorology, oceanography, and environmental sciences.

It only takes a minute to sign up. Connect and share knowledge within a single location that is structured and easy to search. It doesn't make sense to type it again, so I link to it. Maybe the question can be answered here. You may be forgetting that pressure also decreases with height exponentially.

But I digress in answering your question. Let's break down why potential temperature increases with height. This does not mean that the parcel is not adiabatic, though. I'll also take pause here and list a few diabatic processes, and why there may be some justification to ignore them for your mental image. If we'd be living in a dry atmosphere your reasoning is indeed correct. Air would rise adiabatically and air would loose about 9.

This means constant potential temperature. However, Earths atmosphere isn't dry. Potential temperature will rise because if the parcel falls down again it will be warmer at the same level - see below.

This causes clouds and sometimes rain and thus, reduces the overall water content in an air parcel. If such a parcel is now going to fall again it will gain temperature according to the dry adiabatic lapse rate because it lost water during ascension.