Guest Post by Willis Eschenbach
I’ve been reflecting over the last few days about how the climate system of the earth functions as a giant natural heat engine. A “heat engine”, whether natural or man-made, is a mechanism that converts heat into mechanical energy of some kind. In the case of the climate system, the heat of the sun is converted into the mechanical energy of the ocean and the atmosphere. The seawater and atmosphere are what are called the “working fluids” of the heat engine. The movement of the air and the seawater transports an almost unimaginably large amount of heat from the tropics to the poles. Now, none of the above are new ideas, or are original with me. I simply got to wondering about what the CERES data could show regarding the poleward transport of that energy by the climate heat engine. Figure 1 gives that result:
Figure 1. Exports of energy from the tropics, in W/m2, averaged over the exporting area. The figures show the net of the energy entering and leaving the TOA above each 1°x1° gridcell. It is calculated from the CERES data as solar minus upwelling radiation (longwave + shortwave). Of course, if more energy is constantly entering a TOA gridcell than is leaving it, that energy must be being exported horizontally. The average amount exported from between the two light blue bands is 44 W/m2 (amount exported / exporting area).
We can see some interesting aspects of the climate heat engine in this graph.
First, like all heat engines, the climate heat engine doesn’t work off of a temperature. It works off of a temperature difference. A heat engine needs both a hot end and a cold end. After the working fluid is heated at the hot end, and the engine has extracted work from incoming energy, the remaining heat must be rejected from the working fluid. To do this, the working fluid must be moved to some location where the temperature is lower than at the hot end of the engine.
As a result, there is a constant flow of energy across the blue line. In part this is because at the poles, so little energy is coming from the sun. Over Antarctica and the Arctic ocean, the sun is only providing about a quarter of the radiated longwave energy, only about 40 W/m2, with the remainder being energy exported from the tropics. The energy is transported by the two working fluids, seawater and air. In total, the CERES data shows that there is a constant energy flux across those blue lines of about six petawatts (6e+15 watts) flowing northwards, and six petawatts flowing southwards for a total of twelve petawatts. And how much energy is twelve petawatts when it’s at home?
Well … at present all of humanity consumes about fifteen terawatts (15e+12) on a global average basis. This means that the amount of energy constantly flowing from the equator to the poles is about eight-hundred times the total energy utilized by humans … as I said, it’s an almost unimaginable amount of energy. Not only that, but that 12 petawatts is only 10% of the 120 petawatts of solar energy that is constantly being absorbed by the climate system.
Next, over the land, the area which is importing energy is much closer to the equator than over the sea. I assume this is because of the huge heat capacity of the ocean, and its consequent ability to transport the heat further polewards.
Next, overall the ocean is receiving more energy than it radiates, so it is exporting energy … and the land is radiating more than it receives, so it is getting energy from the ocean. In part, this is because of the difference in solar heating. Figure 2, which looks much like Figure 1, shows the net amount of solar radiation absorbed by the climate system. I do love investigating this stuff, there’s so much to learn. For example, I was unaware that the land, on average, receives about 40 W/m2 less energy from the sun than does the ocean, as is shown in Figure 2.
(Daedalus, of course, would not let this opportunity pass without pointing out that this means we could easily control the planet’s temperature by the simple expedient of increasing the amount of land. For each square metre of land added, we get 40 W/m2 less absorbed energy over that square metre, which is about ten doublings of CO2. And the amount would be perhaps double that in tropical waters. So Daedalus calculates that if we make land by filling in shallow tropical oceans equal to say a mere 5% of the planet, it would avoid an amount of downwelling radiation equal to a doubling of CO2. The best part of Daedalus’s plan is his slogan, “We have to pave the planet to save the planet” … but I digress).
Figure 2. Net solar energy entering the climate system, in watts per square metre (W/m2). Annual averages.
You can see the wide range in the amount of sunlight hitting the earth, from a low of 48 W/m2 at the poles to a high of 365 W/m2 in parts of the tropics.
Now, I bring up these two Figures to highlight the concept of the climate system as a huge natural heat engine. As with all heat engines, energy enters at the hot end, in this case the tropics. It is converted into mechanical motion of seawater and air, which transports the excess heat to the poles where it is radiated to space.
Now, the way that we control the output of a heat engine is by using something called a “throttle”. A throttle controls the amount of energy entering a heat engine. A throttle is what is controlled by the gas pedal in a car. As the name suggests, a throttle restricts the energy entering the system. As a result, the throttle controls the operating parameters (temperature, work produced, etc.) of the heat engine.
So the question naturally arises … in the climate heat engine, what functions as the throttle? The answer, of course, is the clouds. They restrict the amount of energy entering the system. And where is the most advantageous place to throttle the heat engine shown in Figure 2? Well, you have to do it at the hot end where the energy enters the system. And you’d want to do it near the equator, where you can choke off the most energy.
In practice, a large amount of this throttling occurs at the Inter-Tropical Convergence Zone (ITCZ). As the name suggests, this is where the two separately circulating hemispheric air masses interact. On average this is north of the equator in the Pacific and Atlantic, and south of the equator in the Indian Ocean. The ITCZ is revealed most clearly by Figure 3, which shows how much sunlight the planet is reflecting.
Figure 3. Total reflected solar radiation. Areas of low reflection are shown in red, because the low reflection leads to increased solar heating. The average ITCZ can be seen as the yellow/green areas just above the Equator in the Atlantic and Pacific, and just below the Equator in the Indian Ocean.
In Figure 3, we can see how the ITCZ clouds are throttling the incoming solar energy. Were it not for the clouds, the tropical oceans in that area would reflect less than 80 W/m2 (as we see in the red areas outlined above and below the ITCZ) and the oceans would be much warmer. By throttling the incoming sunshine, areas near the Equator end up much cooler than they would be otherwise.
Now … all of the above has been done with averages. But the clouds don’t form based on average conditions. They form based only and solely on current conditions. And the nature of the tropical clouds is that generally, the clouds don’t form in the mornings, when the sea surface is cool from its nocturnal overturning.
Instead, the clouds form after the ocean has warmed up to some critical temperature. Once it passes that point, and generally over a period of less than an hour, a fully-developed cumulus cloud layer emerges. The emergence is threshold based. The important thing to note about this process is that the critical threshold at which the clouds form is based on temperature and the physics of air, wind and water. The threshold is not based on CO2. It is not a function of instantaneous forcing. The threshold is based on temperature and pressure and the physics of the immediate situation.
This means that the tropical clouds emerge earlier when the morning is warmer than usual. And when the morning is cooler, the cumulus emerge later or not at all. So if on average there is a bit more forcing, from solar cycles or changes in CO2 or excess water vapor in the air, the clouds form earlier, and the excess forcing is neatly counteracted.
Now, if my hypothesis is correct, then we should be able to find evidence for this dependence of the tropical clouds on the temperature. If the situation is in fact as I’ve stated above, where the tropical clouds act as a throttle because they increase when the temperatures go up, then evidence would be found in the correlation of surface temperature with albedo. Figure 4 shows that relationship.
Figure 4. Correlation of surface temperature and albedo, calculated on a 1°x1° gridcell basis. Blue and green areas are where albedo and temperature are negatively correlated. Red and orange show positive correlation, where increasing albedo is associated with increasing temperature.
Over the extratropical land, because of the association of ice and snow (high albedo) and low temperatures, the correlation between temperature and albedo is negative. However, remember that little of the suns energy is going there.
In the tropics where the majority of energy enters the system, on the other hand, warmer surface temperatures lead to more clouds, so the correlation is positive, and strongly positive in some areas.
Now, consider what happens when increasing clouds cause a reduction in temperature, and increasing temperatures cause an increase in clouds. At some point, the two lines will cross, and the temperature will oscillate around that set point. When the surface is cooler than that temperature, clouds will form later, and there will be less clouds, sun will pour in uninterrupted, and the surface will warm up.
And when the surface is warmer than that temperature, clouds will form earlier, there will be more clouds, and higher albedo, and more reflection, and the surface will cool down.
Net result? A very effective thermostat. This thermostat works in conjunction with other longer-term thermostatic phenomena to maintain the amazing thermal stability of the planet. People agonize about a change of six-tenths of a degree last century … but consider the following:
• The climate system is only running at about 70% throttle.
• The average temperature of the system is ~ 286K.
• The throttle of the climate system is controlled by nothing more solid than clouds, which are changing constantly.
• The global average surface temperature is maintained at a level significantly warmer than what would be predicted for a planet without an atmosphere containing water vapor, CO2, and other greenhouse gases.
Despite all of that, over the previous century the total variation in temperature was ≈ ± 0.3K. This is a variation of less than a tenth of one percent.
For a system as large, complex, ephemeral, and possibly unstable as the climate, I see this as clear evidence for the existence of a thermostatic system of some sort controlling the temperature. Perhaps the system doesn’t work as I have posited above … but it is clear to me that there must be some kind of system keeping the temperature variations within a tenth of a percent over a century.
Regards to all,
w.
PS—The instability of a modeled climate system without some thermostatic mechanism is well illustrated by the thousands of runs of the ClimatePredictionNet climate model:
Note how many of the runs end up in unrealistically high or low temperatures, due to the lack of any thermostatic control mechanisms.
joeldshore says:
December 23, 2013 at 3:15 pm
And as you point out, Joel, these effects only occur when greenhouse gases are involved. But in my specific question to Leif, there are no GHGs. My point remains. In a a non-ghg containing atmosphere, pressure by itself cannot heat the surface by a fraction of a degree, no matter what the pressure-heads might think.
I went over all of this in detail in a previous post, called “A Matter of Some Gravity“, and people are invited to see the full discussion there.
w.
Willis Eschenbach says:
December 23, 2013 at 10:18 am ”
“Steven, suppose we have a superconducting planet with no atmosphere. Alternatively, we could use a regular planet warmed evenly by a thousand suns spaced around it.
Since the planet is at equilibrium, it is radiating the exact amount of energy it is receiving. The temperature is the same at all points, and is the amount predicted by the S-B equation.”
So our with our superconducting planet [say surface is made out Vzwp Plastek ].
And remove chunk of it from surface [meter square sheet of it] and by removing made it so it wouldn’t be conductive. And we insulated one side of it. Then faced towards the sun, and it radiated 1360 watts per square meter, and it’s temperature being over 120 C. So we are at earth sun distance from a star like our Sun.
If we than exclude any reflective nature of this unknown substance when it’s at low angle to the sun, the energy received by the disk area of the planet will divided by surface area to sphere.
So, 1360 watts divided by 4. So surface radiates 340 watts per square meter.
Which assumes side facing towards ground is insulated- and having it have equal temperature
would insulate any heat flowing towards interior.
And with the thousand sun, if remove chunk from the surface, the energy of sunlight from the suns would warm, the Vzwp Plastek or something like Vzwp Plastek which was not superconducting material so it radiated 340 watts per square meter or was about 5 C.
It should be noted that Earth isn’t like a world covered with Vzwp Plastek,
but could more similar to a world like Earth with half such an “Earth” is covered with Vzwp Plastek. If divide this world in half by making a band of Vzwp Plastek extending north and south
to 38 degree latitude. So divided world with two poleward section equaling the surface area
of the middle section [the mostly tropical zone of the planet]. So instead divided by 4, one divides by 2. So the Vzwp Plastek isn’t being a superconductor to region north or south of
38 degree latitude. So instead of 340 watts per square meter it’s 680 watts per square meter.
Or it’s temperature is 56 C.
And other two parts of the planet since in vacuum they could much cooler and since receiving less than 10% of sunlight may be far beyond freezing, though once add atmosphere and other means of conducting heat they would become warmer, thereby more resembling Earth.
As Earth is imbalanced in terms the energy it receives from the sun and the tropics are much warmer than the two temperate and arctic zone.
Of course our tropics don’t have an average temperature near 56 C, the water of ocean is simply unable to reach 56 C due to it evaporation, and there are such things as an atmosphere reflecting sunlight, and etc. But point is it more resembles Earth, then Earth which receives a uniform amount of energy from the Sun.
It’s a better model to start with.
“Stephen, IF an inert atmosphere could raise the temperature above that point, THE PLANET WOULD BE RADIATING MORE THAN IT RECEIVES. Since this is impossible, we can conclude that there is NO mechanism by which an inert atmosphere can warm the surface of a planet.”
But an inert atmosphere can retain heat. And an inert atmosphere does not radiate heat. For an inert atmosphere to lose heat it must heat something which can radiate heat- such a surface or droplet or particles in the inert atmosphere.
“Note that this proof does not simply apply to pressure-based mechanisms. It shows that there is no mechanism by which an inert atmosphere can raise the temperature beyond the S-B limit.”
If Earth was dominated by being heated by air temperature- and one could say this, but one would say with Venus this more the case than with Earth- then if dug a very deep hole on Earth,
1000 meters down that hole the air temperature would warmer. Due to lapse rate. So per 1000 meters it about 6.5 C warmer.
And Venus has similar lapse rate, and Venus is much larger atmosphere than Earth. One needs to go about 50 km in elevation on Venus to get the same atmosphere pressure as on Earth [and at such elevation and pressure temperature is close to hottest it gets on Earth].
stephen wilde says:
December 23, 2013 at 3:33 am
Ulric Lyons asked Willis
“Why and when would it speed up without heating up?”
Because the additional energy is in the form of gravitational potential energy and not kinetic energy.
The change in size or speed of the convective heat engine changes the ratio of kinetic energy and gravitational potential energy within the atmospheric gases so as to keep radiation out to space equal to radiation in from space. That also involves keeping the surface temperature stable despite forcing elements that try to destabilise it.
=======================================
OK that would mean that convection doesn’t actually do any cooling, and does nothing to answer my question to Willis.
Willis 3:54pm: “…argon. Doesn’t absorb or radiate much light or longwave at all. So you can’t assume that the atmosphere absorbs light from anywhere.”
Minor but important point – that’s text book radiative physics in 1st sentence clipped. To be consistent in your last sentence consider this inserted ^ works better: “So you can’t assume that the atmosphere absorbs ^much^ light from anywhere.”
Meaning even mass of argon atm. would feebly absorb and emit IR, having that feeble affect on the surface energy balance.
joeldshore says:
December 23, 2013 at 3:27 pm
this is said to be due to the gravitational collapse (“Kelvin Helmholtz gravitational energy release process”).<i?
Which mostly happened 4 billion years ago. We are just seeing that primordial heat still there, slowly leaking out.
Willis Eschenbach says:
December 23, 2013 at 3:54 pm
It’s argon. Doesn’t absorb or radiate much light or longwave at all.
If you have a completely transparent atmosphere that doesn’t absorb anything, you might as well not have any atmosphere at all. I was under the false assumption that we were somehow talking about real planets with H2O, CO2, CH4, NH3, O3, etc…
joeldshore says:
December 23, 2013 at 3:27 pm
this is said to be due to the gravitational collapse (“Kelvin Helmholtz gravitational energy release process”).
Which mostly happened 4 billion years ago. We are just seeing that primordial heat still there, slowly leaking out.
Willis, I saw for myself the effects of solar activity over the years since ’98, and formed my own hypothesis regarding weather-climate, as does everyone here I suppose. My thinking involves earthly responses from solar activity with some influence by the moon, based on years of observing solar activity levels as they relate to earth weather. It just so happens that I found Piers along the way in my search for answers, and as he is the primary source of long-range weather forecasting based on these premises, I refer to him. However the evidence for what I’m talking about is independent of what Piers says or does.
I don’t need everything spelled out from him in the detail you apparently expect, and while your interpretation of what he offers borders on slander, I’ll give you the benefit of the doubt too. If you know of a longer-range weather forecaster that is more successful than Piers, tell me who that is, and I’ll be glad to give that person the same fair shake Piers gets from me.
If a POWERFUL high-speed coronal hole stream, or a CME, solar flare, or filament eruption takes off from the Sun and travels along the Parker spiral and engages our magnetosphere with protons and electrons AND DOESN’T cause any weather effects, I’ll be the first to admit I’m wrong. I guarantee you no matter what we say, the Sun is going to create extreme weather events here, where the real deadliest space weather really happens, and there’s nothing anyone here can do about it except understand it and watch it happen.
Why is your opinion better than his or mine? All I’ve seen is people here playing it safe. So far today no one here has answered a single honest earnest question I asked regarding solar weather – all I’ve gotten is vitriol because you don’t like Piers. I like Piers because he’s not afraid to tell the warmists how it is. Are you in agreement with the warmists? Are you a warmist? A true believer of CAGW? Do you believe downwelling LWR from CO2 is the reason for extreme weather events?
Can we at least agree that the weather doesn’t cause weather, and that climate change doesn’t cause climate change? Can we agree that understanding the global atmospheric electric circuit is a very important part of understanding weather changes? Can we agree that powerful solar emissions can impact the global atmospheric electric circuit? If so, how? We need to find out. We are at the beginning stages of understanding here, we are on a learning curve. So is Piers. He continually works on improving his methods and his customers have no fear in telling him when he misses, but we don’t abuse him for it. We understand that he’s not perfect. Are you perfect Willis?
Leif says:
Well, like I said, you are much more of an expert in this stuff than me…but I am a bit skeptical. When I see descriptions of the Kelvin-Helmholtz Effect applied to Jupiter, I don’t see them explaining that this as something that occurred in the past and what we have now is just the primordial heat leaking out; I see them describing it as if it is still going on and generating heat.
I’m not saying that you are incorrect (and it all has zero impact on any of the discussion here), but could you at least provide some reference that supports this notion?
Leif writes “There may still be some gravitational settling with heavier elements sinking.”
and then “Which mostly happened 4 billion years ago. We are just seeing that primordial heat still there, slowly leaking out.”
I sense an opportunity for Leif to learn something new here if he would just take the time to do some research 😉
Willis, I note that you have not answered my simple question –
“I’m going to have to ask for clarification. Do you believe strong vertical tropospheric circulation in the Hadley, Ferrel and Polar cells can continue in the absence of radiative cooling at altitude?”
I have been collecting yes or no answers from climate bloggers for the following question –
“Without radiative gases, would strong vertical tropospheric convective circulation cease with the bulk of the resultant stagnant atmosphere trending isothermal through gas conduction?”
So far my results are –
Dr. Roy Spencer (sceptic) “Yes”
Konrad (sceptic) “Yes”
Nick Stokes (AGW believer) “No”
Tim Folkerts (AGW believer) “No”
Joel Shore (AGW believer) “No”
“Trick” (AGW believer) “No”
Doug Cotton (Slayer) “No”
Davidmhoffer (lukewarmer) “No”
“TB” (AGW believer?) “No”
Stephen Wilde (Sceptic) “No”
Willis Eschenbach (sceptic) “unknown”
Willis, do you believe continued vertical circulation across the pressure gradient of the troposphere, strong enough to overcome gas conduction and pneumatically generate the observed lapse rate, would cease in the absence of radiative gases?
Bob Weber says:
“Are you saying there is no scientific evidence in support of Corbyn’s premises and methods?”
The problem is a lack of science in the methods. Theoretical Solar-Lunar cycles don’t work out any better than chance for predicting weekly-monthly temperature deviations from average because they are not actually predicting the short term solar signal that is forcing the teleconnections.
-“I’m going to have to ask for clarification. Do you believe strong vertical tropospheric circulation in the Hadley, Ferrel and Polar cells can continue in the absence of radiative cooling at altitude?”
I have been collecting yes or no answers from climate bloggers for the following question –
“Without radiative gases, would strong vertical tropospheric convective circulation cease with the bulk of the resultant stagnant atmosphere trending isothermal through gas conduction?”
So far my results are –
Dr. Roy Spencer (sceptic) “Yes”
Konrad (sceptic) “Yes”
…. –
There can’t be strong radiative cooling at altitude, because at altitude it is very cold.
And very cold things do not radiate much of their heat energy. They don’t have a lot
to give.
Though it does not matter how warm a gas is in terms how much it can re-radiate- you make nitrogen glow by exposing it to certain wavelengths, and it doesn’t have any relation to the temperature of the nitrogen gas. Or doesn’t have anything to do with the kinetic energy of the gas.
Rockets would be really easy if it did.
So convective is related to kinetic energy transfer of gases.
The only way to stop gas from convecting would be not have the surface warmed by
the sunlight. Though seems that water droplets, which one confuse with water vapor, are related to convection.
So I believe: “strong vertical tropospheric circulation in the Hadley, Ferrel and Polar cells can continue in the absence of radiative cooling at altitude”.
So, Yes
Well Ulric, Piers doesn’t predict temperatures per se. So technically you’re right, but what about someone like me who needs to know whether its going to rain or snow at any temperature so I can get my outside work done in time? It seems like there’s an implied perfection standard applied to Piers, and whenever something doesn’t pan out exactly as he says everyone piles on, conversely, when he’s right he’s only lucky – I mean that is the central message I’m getting from a few people here today, right? You don’t want to give him credit for when he is right, and he’s right a lot.
The method problem can be improved with sufficient magnetic and electric field measurements in three dimensions globally. A fine net to “see” what those teleconnections are doing, how they form, how long they last, the power they convey, and their immediate to long-term influences. We have a long way to go before solar particle and magnetic weather effects are fully understood, yet we can’t afford to ignore space and earth weather connections because of misunderstandings.
I have to say again so many don’t understand Piers’ forecasting method, and are quick to call everything he says “vague” when indeed he is specific about a great many things.
So much focus on temperature is taking away from understanding when and where severe weather will occur, in what time frame, and for how long. Piers excels at that. I think most people know the difference between “very cold” “cold” “warm and humid” and the other qualitative temperature descriptors for weather up to 30 days out that he uses. The Weather Channel doesn’t give precise long-range temperature forecasts either. Their long-term seasonal outlooks are fairly non-specific.
The attention minor temperature anamolies get is really overdone. Who can even sense a difference of 1 degree F or C? People don’t usually die from small changes in temperature, but those extreme weather events are killers. Piers Corbyn simply tries to help people prepare for bad weather, and he rails against governments hell bent on wasting time and money on looney tune carbon dioxide climate theories instead of helping people avoid freezing to death in what he calls Mini Ice Age conditions he says (among others) we’re entering. His heart is in the right place.
Ulric your last point needs clarification. He does forecast specific solar activity levels like the space weather prediction center. Its not hard to plot the motion of an active region as the sun rotates. When active region 1934 reaches geoeffective position on the right-hand side of the solar disk, expect something to happen here if the solar wind from that region builds up with protons and electrons during Dec29-Jan2.
gbaikie 7:46pm: “The only way to stop gas from convecting would be not have the surface warmed by the sunlight.”
Under normal earth conditions in the wild, any fluid in a gravity field will convect if increase its temperature from below. Doesn’t matter whether it has IR active gas well mixed in or not. The way to stop the fluid in a gravity field from normal convecting is increase its temperature from above. Like in Earth’s stratosphere. Zero lapse to +T with +z up there.
gbaikie says:
December 23, 2013 at 7:46 pm
—————————————————–
If you believe – “strong vertical tropospheric circulation in the Hadley, Ferrel and Polar cells can continue in the absence of radiative cooling at altitude”.
– that would put you in the “No” column.
Although there are a few point you may wish to reconsider…
You have stated –
“There can’t be strong radiative cooling at altitude, because at altitude it is very cold.
And very cold things do not radiate much of their heat energy.”
While it is correct that energy loss by radiation does vary with temperature, it appears you are falling into the ERL or effective radiating level trap. The ERL hand-waving used to patch broken two shell radiative models back together is invalidated by a moving atmosphere. Air masses involved in tropospheric convective circulation are not just radiating at the top of their circulation, but on accent and decent as well. Rising air masses are warmer than the air at the altitude they are rising through.
Currently radiative gases in our atmosphere are radiating more than TWICE the energy to space as LWIR than they are absorbing through Net IR flux from the surface and intercepted solar radiation combined. This is because radiative gases are also radiating to space all the energy the atmosphere aquired via surface conduction and the release of latent heat. The atmosphere has no effective cooling mechanism without radiative gases. For a gas atmosphere in a gravity field, the surface is ineffective at conductively cooling the atmosphere.
You also stated –
“The only way to stop gas from convecting would be not have the surface warmed by
the sunlight.”
There is a far simpler way. Convection can be stopped by the gases above the surface level being at the same temperature as gases warmed by the surface. This could be achieved by removing radiative gases from the atmosphere. This would stop radiative cooling and subsidence of air masses and stall tropospheric convective circulation. If air masses cannot radiativly cool and subside, then air masses rising from below with a similar starting temperature cannot over turn them. Layering then starts to occur. The bulk of the atmosphere would then trend isothermal through gas conduction. It is important to remember that the observed lapse rate is a product of continued vertical circulation across a pressure gradient.
Trick says:
December 23, 2013 at 8:58 pm
———————————————
“The way to stop the fluid in a gravity field from normal convecting is increase its temperature from above.”
Trick, you are giving me the sudden urge to buy a lottery ticket and get pig shields installed on the windows 😉
What’s next? Radiative energy loss to space allowing the subsidence of air masses…
” Trick says:
December 23, 2013 at 8:58 pm
gbaikie 7:46pm: “The only way to stop gas from convecting would be not have the surface warmed by the sunlight.”
Under normal earth conditions in the wild, any fluid in a gravity field will convect if increase its temperature from below. Doesn’t matter whether it has IR active gas well mixed in or not. The way to stop the fluid in a gravity field from normal convecting is increase its temperature from above. Like in Earth’s stratosphere. Zero lapse to +T with +z up there.”
Well. Just trying keep it simple.
Gases or liquids if warmer are are generally lighter and therefore rise due to buoyancy.
So with a solar pond due density gradient of salt water one could cancel a warmer saltier water being less dense, thereby stop convect of the hotter salt water rising in fresher water.
Part what I meant not having sunlight is assumption of having rotating planet which warmes and cools during the night. A uniform heat source such from planetary source would tend limit turburent type convection. Or a lapse rate is expression of uniformity of heat dependent on density of air in a gravity field. So if the lapse rate is 6.5 C per 1000 meters. If it’s 6.5 C cooler 1000 meter above ground it is balenced or one does not have difference of density with same gas 6.5 C warmer at the surface [0 meter elevation].
So if not warming surface [from sunlight] the heat from the surface will not have air rising, mixing, and warming the cooler upper atmosphere.
But as for Earth’s stratosphere, I think there are factors involved rather than just lapse reversing- I don’t think it’s matter of inhibting stratosphere convection as such, as much as reaching limit of heat involved. Or if add enough heat or enough density of cloud and conditions of stratosphere
are pushed to higher elevation.
Or mechanism air packet is distrupted by different regime of of stratosphere. Stratosphere region has more to do with distance travelled by an “average air molecule”. Or gas molecules in stratosphere act more as individuals and not like realm of tropsphere of collisions in fractions of a nanosecond. Of course you still have bouyancy at and above the stratosphere- in terms balloons, but less cohesion of air packets.
Konrad says:
December 23, 2013 at 9:27 pm
gbaikie says:
December 23, 2013 at 7:46 pm
—————————————————–
If you believe – “strong vertical tropospheric circulation in the Hadley, Ferrel and Polar cells can continue in the absence of radiative cooling at altitude”.
– that would put you in the “No” column.
Ok. Your rules. But I am bad company I suppose:)
Which ok, I love it, I found something to agree with them about.
-Although there are a few point you may wish to reconsider…
You have stated –
“There can’t be strong radiative cooling at altitude, because at altitude it is very cold.
And very cold things do not radiate much of their heat energy.”-
“While it is correct that energy loss by radiation does vary with temperature, it appears you are falling into the ERL or effective radiating level trap. The ERL hand-waving used to patch broken two shell radiative models back together is invalidated by a moving atmosphere. Air masses involved in tropospheric convective circulation are not just radiating at the top of their circulation, but on accent and decent as well. Rising air masses are warmer than the air at the altitude they are rising through.”
Not sure what you saying, but:
Yes rising gases are tend to more energetic than surrounding air, though as it rise they tend mix and become light dense [expand] as they rise. Or they had higher “energy density” before rising- though say sort of substituted/transformed into potential energy. Or not saying energy is “lost”.
“Currently radiative gases in our atmosphere are radiating more than TWICE the energy to space as LWIR than they are absorbing through Net IR flux from the surface and intercepted solar radiation combined. This is because radiative gases are also radiating to space all the energy the atmosphere acquired via surface conduction and the release of latent heat. The atmosphere has no effective cooling mechanism without radiative gases. For a gas atmosphere in a gravity field, the surface is ineffective at conductively cooling the atmosphere.”
Yeah, well not much fan of idea of any gases radiating much of any energy. I would be say gases are having radiant energy passing thru them.
But trying make easier argument, that there simply is less total energy up there- though the thin atmosphere does have faster moving molecules. And because higher, potential energy.
So each molecule can be said to more energetic, but cubic km of that air if stay up there is
has less energy.
So rather argue with these strange idea everyone seems to have that gas cooling [slowing down] by radiating energy, I put in simpler bin that all it’s energy is insignificant and can not radiate types levels energy involve with heated planet. Or quite simply whatever going on in the stratosphere has little to do with Earth’s temperature or weather [unless it happens to be jet stream].
-You also stated –
“The only way to stop gas from convecting would be not have the surface warmed by
the sunlight.”
There is a far simpler way. Convection can be stopped by the gases above the surface level being at the same temperature as gases warmed by the surface. This could be achieved by removing radiative gases from the atmosphere. This would stop radiative cooling and subsidence of air masses and stall tropospheric convective circulation. If air masses cannot radiativly cool and subside, then air masses rising from below with a similar starting temperature cannot over turn them. Layering then starts to occur. The bulk of the atmosphere would then trend isothermal through gas conduction. It is important to remember that the observed lapse rate is a product of continued vertical circulation across a pressure gradient.-
Again one assuming CO2 or other gases are cooling by radiating.
So with all the CO2 of Venus, it should be cold.
I would say atmosphere cools by falling at night.
Or at night the surface air cools, and the entire atmosphere cools.
Or the lapse rate doesn’t change in the night.
So, question.
Suppose one were to flash freeze Venus. So no atmosphere and hundreds of feet of frozen CO2
on the surface.
How long does it take to warm the planet to earth like temperature, and then back to Venus temperature within 50 C of current global temperature?
Or a year? century? million years? Or never [without something other than sunlight warming it]
or not in a billion years.
Gbaikie
I’m curious about your comment that an atmosphere cannot lose heat except by radiative gasses at high altitude.
As it happens we have interesting discussions about the sun and Jupiter going on here, both of which it turns out emit more heat than they receive. Much of the sun’s energy comes from fusion and “primordial” energy at the core. Leif Svalgaard tells us that it takes around 200, 000 years, if I remember rightly, for a photon bearing fusion or primordial energy from the core to be emitted at the sun’s surface.
But how is this possible? The sun cant radiate any heat from its surface without the aid of radiative gasses, which in the current academic climate can only mean CO2. Thus I have stumbled upon a momentous discovery -the sun only radiates heat with the help of CO2! We know from terrestrial atmospheric science that it does not matter how insignificant the concentration of CO2 is, it still dominates all thermal dynamics in the atmosphere.
The same must be true of the sun, surely? Its CO2 wot dunnit again!
Konrad says, December 23, 2013 at 9:27 pm:
“Convection can be stopped by the gases above the surface level being at the same temperature as gases warmed by the surface. This could be achieved by removing radiative gases from the atmosphere. This would stop radiative cooling and subsidence of air masses and stall tropospheric convective circulation.”
I’m not sure you’re right in the special case of the atmosphere, Konrad. This is how I see it:
Convection on a global scale is not stopped that easily. If the gases above the surface level were at the same temperature as the gases warmed by the surface, then the gases warmed by the surface would simply have to get … even warmer. And they can. The surface still continuously absorbs energy from the Sun and most of this energy will normally be transferred conductively to the air in direct contact with the surface. If that is no longer possible because of a missing temperature gradient, then, well, energy will start piling up. Because then the surface is no longer able to rid itself of energy as fast as it’s coming in. Hence, the surface will start warming from rising internal energy until the gradient is restored. And this cycle would just go on until …
This is exactly what happens in a greenhouse or in any glass-lid box experiment. Somehow stall or in any way perturb free convection away from a heated surface and you’ll get warming.
Only, our atmosphere has no lid. It is free to expand upward. The air being lifted convectively cools adiabatically as it ascends. It is colder aloft than further down. Because of the greater distance from the heat source (surface) and the gradually lower density/pressure away from the centre of the Earth. You can’t make such an air column isothermal just like that.
Rather, the surface would just get hotter and hotter and hotter while the troposphere would correspondingly steadily expand, maintaing the lapse rate, only ‘forever’ stretching the temperature profile (well, at some point it would probably start dissipating into space). The energy constantly being transferred from the surface but unable to escape the atmosphere radiatively would thus continue to accumulate, but would not make the atmosphere isothermal.
And the Earth system would still only give off the same amount of energy per unit of time to space as it absorbs from the Sun. It doesn’t matter what the system temperature is. It matters only how much energy comes in.
“It is important to remember that the observed lapse rate is a product of continued vertical circulation across a pressure gradient.”
By ‘observed lapse rate’ I take it you mean the environmental lapse rate. The adiabatic lapse rate after all is not a product of anything but the specific heat capacity of the atmosphere and the gravitational acceleration of the Earth (and of the H2O release of latent heat in the atmospheric column). The continued vertical circulation starts and ends with surface warming by the Sun. And since the atmosphere is not contained within a closed box and does have a well-defined pressure/density gradient, it won’t be isothermal so easily.
Well, that’s my take anyway …
But this whole hypothetical issue of an Earth atmosphere without radiatively active gases in it is a pretty hard one to argue about, simply because it’s so … completely hypothetical.
I agree with you that the prime task of the so-called GHGs is to cool the atmosphere (and hence, the Earth system) to space. I’m simply not so sure how essential to atmospheric circulation they are …
gbaikie says:
December 23, 2013 at 11:48 pm
—————————————
Both myself (a sceptic who claims radiative gases cool the atmosphere) and Trick, (an AGW believer who claims radiative gases warm the atmosphere) took issue with your post. There may be something in that.
Having conducted a number of experiments related to radiative gases, I can assure you that radiative physics (including radiative gases) is fine, it’s just that climate “scientists” are giving it a bad name.
I could take you through “Tyndall for beginners” with a postage tube, two rubber bands, some cling wrap, a CO2 bike tyre inflater, your TV remote and a cell phone camera. However I am not sure this is the appropriate thread 😉
Willis said:
“But, these scientific points are very different from Stephen WIlde’s nonsense about higher pressure leading to higher temperatures INDEPENDENT OF the radiative greenhouse effect.”
I told you that it isn’t higher pressure per se that does it.
Whatever the pressure ANY gaseous atmosphere whether radiative or not around a rough surfaced rotating sphere illuminated from a point source of energy will have convective overturning.
That convective overturning is a result of conduction between surface and air on the uplift and between air and surface on the descent.
Although it is a net zero energy exchange at equilibrium it introduces a time delay in the transmission of solar energy through the system and that time delay results in a higher surface temperature than for the instant in / out radiative exchange predicated by S-B.
The more mass that is available to exchange energy with the surface or the stronger the gravitational field the more work is needed to move that mass within the atmosphere and the higher the surface temperature will get.
Pressure is just a side effect of mass and gravity, a mere proxy for the combined effect of mass and gravity.
That higher temperature than S-B is what keeps the atmospheric gases off the ground. If the conductive exchange could leak out into the radiative exchange then over time the system would cool until the atmosphere freezes to the ground.
Where there is a gaseous atmosphere of ANY composition then one must have a higher surface temperature to hold it off the ground AND achieve radiative balance higher up.
The S-B prediction is then satisfied at some different height off the ground as Leif said.
Willis Eschenbach says, December 23, 2013 at 4:05 pm:
“My point remains. In a a non-ghg containing atmosphere, pressure by itself cannot heat the surface by a fraction of a degree, no matter what the pressure-heads might think.”
That’s because you don’t understand or don’t want to understand what ‘the pressure-heads’ are actually saying.
It is not the pressure itself, Willis. It is that which the atmospheric pressure is an expression of – the atmospheric weight.
The atmospheric weight simply acts like a resistance to energy transport away from the solar-heated surface. It makes it less than ideal. The surface heat needs to perform work on the atmosphere on top of it in order to be able to escape, by moving it, pushing it up and away against gravity. Convection naturally and spontaneously moves a fluid from hot to cold, from high pressure/density to low pressure/density. So why isn’t this happening spontaneously on Earth from the surface up? Because of gravity. The surface air would stay put even when always inherently being denser, under higher pressure and warmer than the air above it. It’s held in place by the sheer weight of air pressing down on it from above. Until you heat the surface air above the balance point and make it less dense than the air above it. Buoyancy vs. atmospheric weight. Upward force vs. downward force.
If the upward acceleration of surface-heated air isn’t large/fast enough, if it cannot match the absorption rate of incoming energy from the Sun, then the incoming energy from the Sun will start piling up and the surface warms until we find balance.
Kristian says, December 24, 2013 at 12:58 am:
“Rather, the surface would just get hotter and hotter and hotter while the troposphere would correspondingly steadily expand, maintaing the lapse rate, only ‘forever’ stretching the temperature profile (…)”
Sorry, that should rather read “only ‘forever’ extending the temperature profile”.