Guest Post by Willis Eschenbach
To continue my investigations utilizing the CERES satellite dataset of top of atmosphere radiation, here is a set of curious graphs. The first one is the outgoing (upwelling) longwave radiation at the top of the atmosphere (TOA) versus the sea surface temperature, for the northern hemisphere, at the times of the solstices and equinoxes.
Figure 1. Northern Hemisphere TOA outgoing longwave, versus sea surface temperature. Colors represent latitudes, as follows: dark blue, 10°; red 30°; yellow 50°; sky blue 70°. Vertical dashed line is at 30.75°C. Horizontal dashed line is at 300 W/m2. Black solid line shows the surface upwelling longwave radiation (calculated at emissivity = 0.95). Click to enlarge.
I find this graph both interesting and puzzling.
The first puzzle to me is, why is outgoing radiation in July about 230-250 W/m2 from the pole to the Equator? I mean, the upwelling radiation from the surface (solid black line) increases by 50% from the coldest to the warmest areas … but the upwelling longwave is all about the same regardless of the sea surface temperature. How bizarre!
The second puzzle is that there seems to be a fairly hard limit of about 300 W/m2 of TOA upwelling LW. Not only that, but it doesn’t vary much month to month.
The third puzzle is that even up in the Arctic regions, there’s little seasonal change in the upwelling LW. It only swings about 30 W/m2 at the most variable point, and less as you move away from the poles.
Now, what I think is happening at the warmest temperatures is the same thing that the TOA reflected solar showed in my last post—a significant increase in clouds. Let me explain why more clouds means less upwelling longwave radiation. Remember that this is upwelling longwave radiation. Suppose we have some amount X of upwelling radiation coming from the ground. If we interpose a layer of cloud between the surface and the TOA, the cloud will absorb that upwelling LW radiation, and then re-radiate it, half upwards and half downwards. This reduces the amount of upwelling longwave at the TOA, as we see happening at the warm end of the scale above.
Here is the same analysis, but this time for the southern hemisphere.
Figure 2. Southern Hemisphere TOA outgoing longwave, versus sea surface temperature. Colors represent latitudes, as follows: dark blue, 10°; red 30°; yellow 50°; sky blue 70°. Vertical dashed line is at 30.75°C. Horizontal dashed line is at 300 W/m2. Black solid line shows the surface upwelling longwave radiation (calculated at emissivity = 0.95). Click to enlarge.
Want to know what is surprising to me about the southern hemisphere?
I’m surprised at how little the TOA upwelling longwave changes from season to season. The sun comes and goes … but the southern hemisphere upwelling LW is largely unaffected. Every season of the year it’s about the same, 200 W/m2 around the icy antarctic, rising to 300 W/m2 at about 28°C, and then dropping from there. What’s up with that?
My goodness, the amount there is to learn about this incredibly complex system has no end, I can only shake my head in awe …
w.
Sorry, my line spacing seems to be screwed up
“The photon cannot both ‘heat’ the molecule and ‘twist’ it at the same
time. So, in fact, absorption actually reduces the amount of heat that is potentially
available. Yes, I know, it eventually dissipates back into the system by various means.
So what? It was taken out of the system and was then eventually returned.
No net gain or loss. ”
If the photon can increase the Kinetic energy of a gas in terms of translational motion, then it would seem to me, to make difference. I don’t think it does.
But it seems to me that a gas can transfer it’s non-translational motion energies to a solid or liquid, thereby heating a solid or liquid.
And we have liquid water in the atmosphere of all sizes- thousands to billions of molecules.
According to:
http://wiki.answers.com/Q/How_many_water_molecules_are_in_one_drop_of_water
A raindrop of 0.05 mL being, 1.67 × 10^21 molecules.
Agree with what Konrad says. October 9, 2013 at 1:57 pm. Especially:
“Without radiative gases, tropospheric vertical circulation would stall and the atmosphere would trend isothermal by gas conduction. (Dr. Spencer got this right). The surface would experience severe temperature variations but only over land. (Dr. Spencer got this 29% right). The resultant isothermal temperature would be set by surface Tmax. ( Dr. spencer got this wrong and used Tav, and a Tav too low at that).
….
Our atmosphere is therefore cooler due to radiative gases.”
Without GHG will atmosphere only be cooled by sensible heat with surface. But still heated by sun SW. To balance that will the heat have to go the opposite way compared with present conditions, which is now to atmosphere from surface. Atmosphere have then to be significant warmer than Earth surface to change direction for heat transfer to be from atmosphere to Earth surface and balance the heat flow.
Earth surface will be cooler since the outgoing LW will be from the surface. But the atmosphere above a very thin layer will be warmer, drier and more stable, probably close to Tmax in temperature.
Hard to digestive?
Willis, as soon as I posted my comment, i realized that I didn’t take the directly absorbed solar by atmosphere (and clouds) into account. I was only looking into the surface/atmosphere heat exchange, but there’s also reasoning behind this.
Regarding my first statement, I took the numbers from NASA energy budget with 91% atmospheric and clouds (64/70) and 9% surface (6/70).
Regarding the sources of atmospheric energy, you’re wrong. You forgot to subtract the ‘backradiation’ from your 340 W/m2, which is the (net) LWIR input from the surface . This is clear from adding up your sources, 68+22+76+340=506 W/m2! Your atmosphere would heat up very quickly – it loses only 197 W/m2 to space, according to your reworking of the budget.
Anyway, the sources of energy in the atmosphere are (100% is incoming solar energy):
Directly absorbed solar by atmosphere and clouds: 19%
Non-radiative fluxes from the surface: 30%
Radiation from the surface: 15%
Total: 64%
So, 47% is non-radiative and 53% is radiation, but this includes directly absorbed solar by atmosphere and clouds. Considering only surface/atmosphere heat exchange (directly absorbed solar is not transferred downwards and is re-radiated back to space), it’s:
Non-radiative fluxes from the surface: 30%
Radiation from the surface: 15%
Total: 45%
So, 67% is non-radiative and 33% is LWIR radiation. This was my point. Most of the energy flux from the surface to atmosphere is non-radiative (convection and evaporation).
http://edro.files.wordpress.com/2007/11/earths-energy-budget.jpg
But it seems to me that a gas can transfer it’s non-translational motion energies to a solid or liquid, thereby heating a solid or liquid.
I do not disagree with this at all.
The fact remains that absorption does not increase the temperature of the molecule. That seems to be the key point.
In every bit of of information on the web about absorption in atmospheric gases it implies that the absorption increases the temperature of the molecule. When you move away from “climate science’ you find that there is no implication of such.
Willis, you may already know all of this but I’ll post this because I think it ties in with what you are doing with water vapor.
I started my short journey thinking about a high desert, if you’ve ever been there at dusk you can feel the warmth of the air being sucked out very quickly, where does it go?
In Phoenix we have what’s called a monsoon season characterized by higher humidity and temperatures and at night the Temperature remains high, why?
Water vapor! Humidity!
Water vapor in the troposphere acts as a greenhouse gas. As the amount of water vapor in the air increases, the amount of longwave radiation held within the troposphere also increases. When there is not much water vapor in the air, longwave radiation emitted from the earth’s surface will more easily escape to space. These nights will result in significant cooling if the initial dewpoint depression is large. (Dewpoint depression = difference between Dewpoint and Temp, the closer the two are together the more water vapor. Clouds are regions of a high density of saturated air, (which form cloud droplets). Clouds (especially low thick clouds) have a high ability to absorb and re-emit longwave radiation. Thus, on cloudy nights much less longwave radiation is able to escape to space.
When the surface temperature drops to the surface dewpoint the cooling rate is decreased thereafter at night due to the latent heat of condensation release (occurs at surface when dew forms). Once the temperature drops to the dewpoint, the temperature tends to decrease very little beyond that point. This is especially true for air at high dewpoints since much more latent heat release occurs with warm and humid air.
The difference between the high and low tends to be much greater on dry clear 24-hour days than on warm cloudy 24-hour days. This is due to the rate of cooling being greater in dry clear air at night and the rate of warming being greater in dry clear air during sunlight hours.
You should be able to prove that water vapor performs this function much better than CO2 ever could and at a much larger concentration in the atmosphere than 400ppm of CO2.
I’m not sure how to go about this but I’m willing to bet you could replace the water vapor with CO2 and never get the same effect. Though both are considered GHG’s I believe water vapor contributes much more than CO2 to the weather and climate of the Earth.
Thoughts?
BBould,
Please read http://www.kidswincom.net/CO2OLR.pdf and let me know what you think.
I’m not a scientist so your article was above me in some areas but you conclude what I concluded also it seems.
“Globally, the measurable effects of atmospheric water on reducing the rate
of OLR are orders of magnitude greater than any probable effects of
atmospheric CO2.”
Can we do an experiment to test this? Saturate air with water vapor and compare with air saturated with gross amounts of CO2. See which one loses heat quicker. You could also combine the two and also test dry unsaturated air for a baseline?
BBould,
The observed regional and time difference effects on OLR are the experiment you are thinking about. You have the contrast of high humidity(and clouds) near the equator and very low humidity at the poles. While CO2 has been increasing rather uniformly globally. The regressions that I have done indicate the relative magnitudes of the effects.
BTW, there is one difference – your statement is true Meteorologists use it all the time Dewpoint.
fhhayni: “The regressions that I have done indicate the relative magnitudes of the effects.”
I don’t understand how you got there but I understand the significance of relative magnitudes of the effects and I believe water vapor is probably the control knob of climate.
To BBould,
More to think about. Data analysis that I am now doing tends to indicate that the temperature and amount of water in clouds at the equator is controlling the global atmospheric concentration of CO2 and anthropogenic emissions are having little effect on the rise.
fhhaynie: “amount of water in clouds at the equator is controlling the global atmospheric concentration of CO2 ”
When you say control what do you mean? Inhibit, lesson, do away with?
Can CO2 hold as much energy as water vapor or more even? I would think and I may be wrong, that both have similar properties of retaining heat and if so CO2 is miniscule compared to water vapor.
It’s the change in equilibrium between air and water droplets in clouds as they cool with rising altitude. Thunder clouds pump air and water into the upper atmosphere. When the cold water freezes at the top, it releases CO2 that it has absorbed. The cold water that falls as rain returns CO2 to the ocean from which it came. This is a complex mass and energy balance problem to solve.
coldlynx, if you are still monitoring this thread I didn’t realize you responded, that is until someone else pointed your question out, what of coldlynx’s question?
First realize what that spread really is, it was never meant to be viewed public but got grabbed and stuck into a top post. So some of the scribbles at the right are just notes to myself. And yes, you can view that also as having an effective radiative altitude as long as it is not meant literally to be “real”, as an appx. five and half km radiating upward single layer. It is excel solver balanced, very simple. As you said most surface radiation is nearly immediately absorbed very low. What was curious to me is that the ~265 W/m² net IR eyeball-matches on all of those eight plots. Thought better bring that back up for others to think on. Need to dig backwards more to find specifically where it was being discussed over a year or two ago here at wuwt. That figure keeps reoccurring.
Could it be roughly the sum of the global mean cloud tops partially and the clear-sky mean remnants from all atitudes partially per lbl? Seems feasible but probably impossible to extract those two means.
Didn’t mean to just ignore.
fhhaynie: ” When the cold water freezes at the top, it releases CO2 that it has absorbed. ”
So what you are saying is that water vapor absorbs CO2 in the atmosphere, Nimbus clouds freeze the water releasing the CO2 which reabsorbs with the falling rain?
I don’t know enough to argue that point, do we know that CO2 is absorbed by water vapor?
To BBould,
There may be some reaction between water vapor and CO2 gas, but I think the absorbtion of CO2 in water droplets in clouds is the rate controller.
Essentially what you are predicting is that Thunderstorms “scrub” CO2 out of the air correct?
BBould,
Only part of it. A larger fraction is being pumped into the upper atmosphere where it is transported toward the poles, where it is sucked up by frigid sea water. It is a very dynamic system that CAGW models poorly try to emulate. If CO2 is radiating at the top of the atmosphere rather than near the surface, one would expect a “cooling” effect rather than a “warming” effect on the surface.
Yes Wayne; All heat that enter planet Earth willl leave the planet. Exact the same amount. With or wtihout GHG. GHG itself do not change the heat balance. Only change the average altitude for outgoing LWR to space. That altitude have an impact on surface temperature.
That is not the same thing as heating or cooling of planet Earth
Changes in cloud cover do change the albedo which change the heat balance which per definition is heating or cooling the planet.
Once again. GHG (just gases) do not change the heat balance to space. It just change the location as avearage altitude from where LW escape from the atmosphere.
Coldlynx & Edim,
Good to see a few others getting close to the answer. The critical role of radiative gases in cooling our atmosphere far outweighs any role they have in heating it or slowing the cooling of the land surface.
As I have often said, global warming was a global IQ test with results permanently recorded on the Internet. Any who thought they could apply SB equations to a moving gas atmosphere failed.
fhhaynie: If CO2 is radiating at the top of the atmosphere rather than near the surface, one would expect a “cooling” effect rather than a “warming” effect on the surface.
I would expect CO2 to radiate like other GHG’s but that’s where the conundrum comes in don’y you think?
I believe Water Vapor controls the climate.
Of course. Water vapor, water droplets, and ice crystals at the top of clouds are radiating a lot more than a small amount of CO2 in the upper atmosphere. The bottom of the clouds primarily radiate toward the surface. There is little radiation through the thick clouds of a tropical thunderstorm. Convection is transferrng energy upward. Think radiation is “line of sight and speed of light”.
fhhaynie: “Think radiation is “line of sight and speed of light”.
I like that very much it makes sense at night in a desert with dry heat.
coldlynx, you seem to think I was making a some kind of statement by posting that. Not so. That was just another much better view (to me) of the TFK graphics data that I also deplore how they drew it, has misled so many over the last four years. I agree with what you are saying, except I have come to the understanding in the last year or so that co2 does not even warm the surface at these concentrations. The spectrums show co2 lines sitting at ~215K and adding co2 is never going to affect that. All GHGs radiate at their local T but co2 in the thick tropo can’t even reach space to make a difference, all is in radiative statis, so there is a null effect until approaching the tropopause in co2 lines. Water being not quite as agressive an absorber is a different story and the spectums show that clearly, it can reach space much earlier.
You can’t add more trace co2 to have the atmosphere absorb more if it is already absorbing right at 100% in its lines and very near the surface right now.
You are saying the lapse would change, I am saying it wouldn’t even do that. Guess I have gone from a warmist years ago all of the way to denialist. Would love to carry this discussion on but I can’t for a while, don’t know how long.
Agree Wayne
LWR in CO2 spectra measured from satellites have a temperature 220K that indicate the origin are at tropopause/ stratosphere altitude. More CO2 at this altitude will increase outgoing LWR if temperature would remain.
According to IPCC and science will this result in stratospheric cooling. Lower temperature reduce outgoing LWR according to SB law and balance out the incoming energy. And we have measured that by for example RSS.
But the mistake they do is that they belive in a change lapse rate from top to down in atmosphere and claim more heat is trapped in lower layer would be sustained. As seen by net heat transfer balance is radiative LW heating of the atmosphere not the major way the atmosphere are heated by. And a steeper lapse rate is not possible since that will create more convection, aka Willis thunderstorm thermostat, which take care of the heat transfer from surface to atmosphere.
The discussion should be about if this increased convection due to CO2 will increase atmosphere water vapor and by that increase average altitude of outgoing LWR to space and casue higher temperature on ground due to lapse rate. Note here: more water vapor will casue more clouds that reduce incoming solar energy by ichanging earth albedo and that is a reduced heat balance. These two functions of water balance each other.
In my opinion have changing UV from sun, Cosmic rays, yes even contrails, larger impact than CO2 of the amount of water vapor in our atmosphere.
Over and out.
coldlynx says:
October 10, 2013 at 11:15 pm
Thanks, coldlynx. Your comment inspired me to to look at the effective temperature of the TOA total upwelling LW radiation. (Note that this is not the “LWR in CO2 spectra” you refer to above.) Here’s that chart:
The effective temperature has been calculated in the usual Stefan-Boltzmann fashion, with an emissivity of 0.95.
w.
Willis.
“The effective temperature has been calculated in the usual Stefan-Boltzmann fashion, with an emissivity of 0.95.”
WTF???? The emissivity of the earth is closer to .75 based on measurements made from a Mars probe on its way and pointed back to earth!!!
Willis:
The temperature by wave number to show for CO2.
http://tinyurl.com/p5jp9kh
210K
Hope You take it right way. I could not resist. I like Your ideas and energy.
wayne says:
October 10, 2013 at 4:13 pm
You can’t add more trace co2 to have the atmosphere absorb more if it is already absorbing right at 100% in its lines and very near the surface right now.
CO2 only absorbs at 100% at the center of the band there is still scope for absorption in the wings of the band that is what gives the logarithmic dependence. Addition of more CO2 will increase the absorption.