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.
Flaming hockey sticks!
Willis,
I am an engineer who analyzes buildings, and your thought process is remarkably similar to mine…. It is a very large complex puzzle, yet to be solved. Keep digging, I know yow will find the answer.
While I don’t doubt your professionalism and integrity, why has no one looked it this in the past 20+ years?
Is it because those who figured it out couldn’t make a dollar off it???? Follow the money and you will typically find the answer.
Interesting graphs. Well done. I am looking forward to the comments.
Upwelling and downwelling isn’t a 50/50 ratio. Most of the atmosphere is above the horizon so even some “downwelling” radiation is still aimed at the stars. Thanks to our cleaning up the air we breath our air is more transparent (fewer aerosols, smoke, tire particles, soot, etc) so it is possible to graze the horizon with light and have it leave earth forever. The bandwidth of our atmosphere is much improved over my lifetime and our angle of radiation of light is wider than it was when coal was king. I wonder if the satellites deal with this. Sorry I can’t find the link to the study just now of the impact of changing atmospheric transparency.
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.
======================
awe Willis, I know you are smiling. Me too.
Well lo and behold Willis finally “discovers” what I was trying to point out to him across many prior articles, let’s see, before December 14, 2012 since that is the date Roger at TalkShop took serious what I was saying and published a small and simple correction to TFK’s new and “improved and balanced” energy budget. See the 264 W/m² outgoing averaged global upwelling LWIR that is what you see in the CERES data.
Model: http://i46.tinypic.com/21931xt.png (the blue cells are the only given parameters)
Article: http://tallbloke.wordpress.com/2012/12/14/emissivity-puzzle-energy-exchange-in-non-vacuums/
Yes, it does seem our planet does have an effective emissivity of right at 0.67, globally averaged, or that is what I gather from your plots Willis.
The atmosphere lower part block most of IR upwelling from earth surface.
The outgoing IR measured at TOA are mostly from higher colder part of atmosphere. That IS the green house effect. Coldest part of atmosphere is by the way in the tropics.
wayne says:
October 8, 2013 at 10:55 pm
Wayne, I don’t have the slightest clue what you’re talking about. I’m banned from Tallbloke’s Talkshop, and I haven’t any idea what you were “trying to point out” to me, either there or elsewhere. Your tinypic is of no help either.
Nor am I impressed by your tone …
w.
Carnwennan says:
October 8, 2013 at 10:13 pm
Definitely, what’s not to like?
Best regards,
w.
Willis: “Wayne, I don’t have the slightest clue what you’re talking about.”
Thanks Willis, didn’t think you would. Maybe some others can see through it.
What band do they consider “LW”? I would expect that maybe the power doesn’t change, but the wavelength will. I would expect the wavelength to increase as the temperature cools. The amount of power radiated will probably remain unchanged until the surface temperature started to near equilibrium with space. For example, if the sun were to turn off right now, earth would continue radiating heat into space but the wavelength would get longer and longer as it cools. There would likely be a “burst” of heat as various gasses condense out of the atmosphere depending on their latent heat but overall the amount of power wouldn’t change much until we got below about -250F or so. What is the variation of outgoing LW from the moon at the equator across the dark side from terminus to terminus? My guess is it won’t vary much but the frequency of it will. It is probably radiating pretty close to the same amount when the surface first goes dark as it is just before dawn. It would keep radiating, too, if it could, all the way down to double-digit kelvins and then at that point portions of the colder parts of the surface start to come into equilibrium with space and the radiation begins to fall off.
In other words, if I have a radiator that can radiate 100W/m^2 and it is +200F in a room that is -350F it will continue radiating 100W/m^2 when it has cooled to +100F and when it is at 0F. When the power begins to fall off, that means it is no longer cooling. All this says is the efficiency of the radiator doesn’t change much by season. It doesn’t say much about temperature. Earth cools at about the same rate in winter as it does in summer. The winter hemisphere doesn’t receive as much energy as it did in the summer so the temperature falls. In summer, it receives more than it radiates and the temperature rises. But the radiation is, apparently, relatively constant. For some reason I don’t find that puzzling at all.
Something that l think is been overlooked is what impact does the increase in Noctilucent clouds have on the atmosphere. The brightest and extent of these clouds waxes during the summer months and wanes during the winter. Also these type’s of clouds rarely stray further then 50 degree’s from the poles. These clouds are also known to be highly reflective to radar and can only be seen when the sun is below the horizon.
Think of an inner tube with a leak in it. Imagine the leak is constant (doesn’t change with pressure) in CFM per minute. But now imagine I have a varying amount of air (energy) being pumped into it. Imagine that air (energy) varies in roughly a sine function. As the amount of air being pumped in increases to a rate greater than the leak, the inner tube swells (hemisphere heats) and as the amount of ingress declines below the amount of leakage the tube shrinks (hemisphere cools) but the rate of air coming out of the “leak” won’t change until the inside begins to reach equilibrium with the outside. The “global warming” argument is that CO2 reduces the size of the “leak” and reduces the amount of heat allowed to escape. And that would probably be true if we had some convective barrier that was a clear piece of solid CO2 like glass is in a greenhouse. The convective “lid” on our “greenhouse”, though, is the tropopause which allows that heat to be transported well above most of the atmospheric CO2. Even worse (for the warmanistas), if you think of the atmosphere from ground to tropopause as a balloon, when you heat it, it expands (troposphere rises). This increases the effective surface area of the balloon meaning that it can still radiate from the tropopause at the same watts/m^2 but it now has more m^2 from which it can radiate. So when you try to warm the troposphere, it just expands a little and the temperature stays the roughly the same. Well, it might increase a tiny bit, but not by much. The expanding tropopause results in the excess convective heat being radiated away over a larger surface area. It is like a radiator that expands to a greater surface area as you heat it.
some pretty colors in the graphs…might make some good art
In a greenhouse, the LW IR blocking entity is at the convective barrier and prevents the air from rising above it to dissipate its heat. In our atmosphere, the air CAN rise above the LW blocking entity. Imagine a conventional greenhouse but imagine air could permeate the glass roof. It wouldn’t be very effective, would it? That’s what happens on Earth. Most of the CO2 (most of the gas, period) is close to the ground. At 50,000 feet where water might be condensing/cooling from the top of a thunder head, very little of the total atmospheric CO2 lies between it and space. If I radiate 1 watt per m^2 at the surface and radiate 1 watt per m^2 at 50,000 feet, I think it’s a safe bet that the energy radiated at 50,000 feet has less chance of impacting a CO2 molecule and is more likely to pass right out into space. A conventional greenhouse is a bad model for an atmosphere. In fact, I would be willing to bet that if Earth had a pure CO2 atmosphere at the same atmospheric pressure it has today (1.0 bar), it would be cooler than it is now at the equator but warmer at the poles (assuming a perfectly dry atmosphere) because CO2 would be better at spreading the heat around.
Wayne; from your links:
LW resident in atmosphere? That is a very unusual way to explain ordinary heat transfer.
But what is the point? You, Willis and everyone else show that most of outgoing LW at TOA are from the atmosphere not direct from the surface.
And since the value is low and more or less constant is the average altitude for LW outgoing rather high, and therefore cold.
Use the middle of the atmosphere at 500 mb, or 5,500 meters (18.000 ft) as example.
Temperature is reduced 6 K/1000m and that is average 33K colder than on earth surface.
And the Green house effect is, tada 33K as well. Not a coincident.
http://en.wikipedia.org/wiki/Greenhouse_effect
The temperature on ground change if the average altitude of this outgoing LW change. And what can change at 5,500 meters (18.000 ft)? Cloud maybe?
Willis,
” This reduces the amount of upwelling longwave at the TOA, as we see happening at the warm end of the scale above.”
Realy?? For how many seconds?? Or is some of it simply frequency shifted when downwelling is absorbed by the surface and reemitted??
gopal panicker says:
October 8, 2013 at 11:46 pm
Thanks, gopal. I always strive to present my findings in a way that is lovely as well as informative … no reason science can’t be beautiful.
Regards,
w.
Willis, I take it you are using the CERES-LW band 8-12 microns. Do you have the actual radiometer data, or you using a NASA interpretation of that data? I am looking for the along track data from a single area so I can observe the change in radiance at angls from normal.
Since the CERES instument has a fixed detector solid angle thr measurements should not vary with angle if the earth has anything like a Lambertian surface. Thank You! -will-
willis says:
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?
=========================================================
In a word: Antarctica.
First, the Southern Hemisphere is mostly ocean, there’s only a fraction of the
land of the NH. The Southern Ocean is huge.
Secondly: the Antarctic ice cap is very high at the centre. Cold, dense air pours
down off that cap and across the Southern ocean, 24/7. The Roaring Forties are
always stormy. The weather fronts created by the cold gale march in monotonous
line from West to East.
Antarctica is the `weather factory’ for the SH
It’s my guess those would be why it’s so constant. No much land to warm, and a
constant gale of frigid air from the south.
Hope these ideas help…
” In fact, I would be willing to bet that if Earth had a pure CO2 atmosphere at the same atmospheric pressure it has today (1.0 bar), it would be cooler than it is now at the equator but warmer at the poles (assuming a perfectly dry atmosphere) because CO2 would be better at spreading the heat around.”
I think if increase CO2 by 2500 times it would finally be enough measurably increase Earth average temperature 🙂
But if you cooled the tropics, you cool the world.
It’s geometry. More surface area near equator.
And don’t see how a CO2 atmosphere cools the tropics.
To cool the tropics you could lower night time temperature- so their is a bigger difference than there is now between night and day. Or significantly reduce daytime temperature. I don’t see how CO2 would do either.
The best way to warm the poles is to increase average ocean temperature- cooling the tropics wouldn’t do this.
Willis, are you aware that in global average ~90% of the TOA outgoing longwave is atmospheric radiation and only ~10% is surface radiation? Furthermore, most of the energy radiated by the atmosphere is gained non-radiatively from the surface. Just asking.
http://edro.files.wordpress.com/2007/11/earths-energy-budget.jpg
dp says
“The bandwidth of our atmosphere is much improved over my lifetime…”
To my simplistic thinking that explains everything. Having removed most of the atmospheric pollution we were responsible for to start with, the Earth’s average temperature has increased slightly. So we are responsible for the warming, such as it is.
I remember the smogs of the 40s and 50s, and I lived in the country.
a 28*C span is about 10% of the Kelvin temperature of 300K. Outgoing LW radiation goes as the 4th power of the Kelvin temperature, so it should vary by about 40%. A variation from 200 to 300 W/m2 is about right. Reduced values, may be the effect of opaque clouds upper in the atmosphere radiating at a lower temperature than the ground.
Pretty much all that the CERES satellite is sensing in outgoing LWIR is energy emited by radiative gases, predominantly water vapour, in rising, translating and descending air masses at the top of the Hadley, Ferrel and Polar tropospheric convection cells.
Most of the energy being radiated by these air masses was not acquired by outgoing surface IR but rather by surface conduction and the release of latent heat from condensing water vapour.
If these air masses did not contain radiative gases and were not strongly radiating LWIR to space, they would rise but not lose energy, buoyancy and subside. Without radiative gases there would be no strong vertical convective circulation below the tropopause.
Without strong vertical convective circulation, the atmosphere would trend to isothermal (no lapse rate) with its temperature set by surface Tmax. Poorly radiative gases such as O2 and N2 stagnated at altitude would then start to radiatively super heat, just as in the thermosphere. Without radiative cooling and strong vertical convective circulation, most of our atmosphere would superheat and boil off into space.
Apparently some idiots want to reduce the amount of radiative gases in our atmosphere…
Willis,
Are you audaciously suggesting that the Earth’s atmosphere & thus climate, may be pretty much self-regulating as regards heat gain & loss? Who’d a thunk it? All barring Ice-Ages of course!
On a lighter note, the climate here in the PDREU state of UK is starting it’s usual slide into autumnal tones, cooling, damper, (for a change 😉 sarc), At least we had a decent summer compared with the drought that never actually lasted until December of 2012 (& was a wash out), according to our highly paid taxpayer funded chums at the Wet Office! It doesn’t hurt to remind them every now & then, either! They remind me of the guy who loses every bet he makes, until one day he gets it right, then crows about his expert judgement for ever & a day! Ho hum.
“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.”
Upwelling LW will hit the bottom of the cloud layer, but because the clouds are mostly opaque to IR, you shouldn’t get much upward radiation. I’m guessing the cloud layer will be colder on the top and warmer on the bottom than you would expect from just the difference in altitude, i.e., the cloud will act as insulation would.
Quite simply, global air circulation changes as necessary to match outgoing longwave with incoming shortwave at ToA over time.
If anything seeks to disturb ToA energy balance then the global air circulation applies an equal and opposite negative response after a period of delay whilst the necessary circulation changes take effect.
I’ve been telling you all that for years and now Willis has noticed the effect.
It is an extension of the Thermostat Hypothesis (not original to Willis) to the global scenario.
The only things that can change total system energy content and globally averaged surface temperature are more atmospheric mass, a stronger gravity field or more ToA insolation.
Everything else just causes circulation changes in both air and oceans – the oceans should be regarded as part of the atmosphere for such purposes.
The sun and oceans affect the circulation in tandem to shift climate zones by up to 1000 miles over the millennial solar cycle.
How far would our emissions shift them?
I’d guess less than a mile.
“The first puzzle to me is, why is outgoing radiation in July about 230-250 W/m2 from the pole to the Equator?”
It’s not so surprising if you relate it to emitting temperature, which in that range is about 255°K (S-B). Most upwelling LW at TOA originates from GHG near the tropopause, and the temperature there is lower than 255K. The tropopause is actually higher and colder near the Equator (than the poles). Less than a quarter comes from the surface, if not cloudy, or the cloud tops otherwise. That’s where warmer SST counts, but it’s only for a fraction.
A more interesting question is how the emitting layer gets enough heat to stay at the temperature it is at. That’s a tribute to poleward heat redistribution.
Willis:
I write to ask a genuine question posed because I am not clear what you are attempting to assess by consideration of upwelling LW alone.
The total radiative output of the Earth will always almost equal the input of solar radiation to the Earth for radiative balance to exist. So, small global temperature changes will only provide a small radiative imbalance while the system adjusts to obtain radiative balance.
Hence, a near constant LW upwelling implies a near constant upwelling SR as observed from space by the CERES satellites. But, so what? The observed upwelling radiation is from the surface and all atmospheric altitudes.
I recognise that you are plotting the LW as a function of SST for different latitudes. And that may indicate something, but I am failing to see what that might be. I note your three “puzzles” especially your first one, but my question is
are you plotting the data in hope that something can be seen or are you seeking some specific information?
Please note that my question is sincere and is not mischievous. It is possible that if I have ‘missed the point’ then others may have, too.
Richard
Ooops!
I wrote
Hence, a near constant LW upwelling implies a near constant upwelling SR as observed from space by the CERES satellites
I intended to write
Hence, a near constant LW upwelling implies a near constant upwelling SW as observed from space by the CERES satellites
Sorry. Richard
Upwelling LW from the tropopause is effectively decoupled from SST because the GHG in the atmosphere and the water cycle distribute the energy through the whole of the atmosphere both vertically and horizontally.
Convective processes cannot get much significant energy into the tropopause, the cloud layer is much lower on average.
The role of CO2 in mediating the movement of LW energy from the surface to the tropopause has been known for at least a century and was accurately defined by military research in the fifties. The energy emissions at the TOA are thermodynamically constrained to match the incoming Sw energy except over short term imbalances. Extra CO2 alters the thermal gradient between the surface and TOA, it would be informative to compare the outgoing LW with the downwelling LW measurements made over the last few decades.
Does anyone know where the EDRO energy budget illustration’s source, I would like to read the article that goes with it
Nice one Willis,
its just amazes me what is hidden in the woodwork !
“I’m surprised at how little the TOA upwelling longwave changes from season to season. ”
Well what would consider a lot. The whole climate discussion is bogged down in arguing about feedbacks measured in single W/m2 units. That level is invisible on the range your plotting.
If you want to see a difference compare your SB line to a linear regression of the data. I suggest you separate tropics , we know they act in a rather special way and see fairly linear relation up to your red colour coding.
Fit linear regression to extra-tropics across the board and you will start to see a seasonal difference in slopes. You may want to consider cropping off < -1deg C where ice phase change will mess up temp relationship.
There's a slight upward curvature too, but linear will get a first stab at it.
The comparison of the slope to the ideal SB line will give you an estimation of the (negative) feedback at play and how it varies with the seasons.
The upward curvature makes it slightly less than linear suggesting the presence of a weaker +ve f/b too.
A strong linear feeback would totally flatten the line. What happens in the tropics, if I'm not mistaken, has to imply strong, non-linear feedback. Though I may have said that before 😉
stuart L says: October 9, 2013 at 2:53 am
“Does anyone know where the EDRO energy budget illustration’s source,”
Link.
If seasonal variations are small, an averaged annual map like provides a good visualisation:
http://en.wikipedia.org/wiki/File:Erbe.gif
Also note:
http://www.giantworlds.org/images/Thermal_Jupiter_cut.jpg
http://cdn.physorg.com/newman/gfx/news/2005/Saturn-hot-spot.jpg
I think I’ve never heard so loud
The Gods are laughing in the clouds.
==================
Nick Stokes says:
It’s not so surprising if you relate it to emitting temperature, which in that range is about 255°K (S-B). Most upwelling LW at TOA originates from GHG near the tropopause, and the temperature there is lower than 255K. The tropopause is actually higher and colder near the Equator (than the poles).
===
Very relevant points. The main GHG being water vapour of course.
I do wonder if the difference between Northern and Southern hemispheres for the appropriate Summer/Winter and Spring/Autumn (i.e. compare N Dec to S Jun & N Mar to S Sep, etc.), given that only geography is then changed, would not reveal the range that geography provides in these figures. That might provide some envelope to the outcomes and provide some sort of global baseline.
Willis, if you would read up on what we already know about this stuff, you would not be so perplexed.
Roy Spencer says:
October 9, 2013 at 4:23 am
————————————————
Dr. Spencer, if you stopped believing that adding radiative gases to the atmosphere would reduce the atmospheres radiative cooling ability, you would not be so wrong 😉
The Upwelling Radiation is so similar because of the equator to poles transfer of energy and the fact that an extra W/m2 of energy at the poles means a greater temperature increase than a W/m2 at the tropics.
The net Greenhouse Effect varies considerably by Latitude in both the net Temperature it adds and in the implied W/m2 of Energy it represents.
For example, the North Pole is on average 80C warmer than it should be just based on the net Solar radiation it receives. (Yes, you read that right, an astounding 80C). This translates into about 190 W/m2 of energy transfer from tropics/greenhouse effect versus the global average of 150 W/m2.
Technically, the implied Greenhouse Effect is actually the lowest at the Tropics as energy is transferred away to higher latitudes. It is -25W/m2 lower than the global average of 150 W/m2.
Implied Greenhouse Effect by Latitude. In effect, there is more consistent outgoing long-wave radiation at all the Latitudes.
http://s7.postimg.org/9ny2kh8vv/Greenhouse_Effect_by_Lat_Temp_C.png
http://s8.postimg.org/5x71x8qn9/Greenhouse_Effect_by_Lat_W_m2.png
I have to say that I find the color curves above almost impossible to read. They appear to be solid bars of vertically AND horizontally distributed points, and I don’t know how to interpret that. So I’ll refrain from commenting.
It might be better to aggregate the data and present it with vertical and horizontal error bars on some scale, I dunno. Or to just present the TOA spectroscopy from which these are presumably derived.
I’m actually working a little bit on trying to understand the feedback involved in a set of very simple single slab ODEs (basically the ones from Petty’s book turned into model ODEs) where I assume that atmospheric absorptivity is a parameter that is monotonically connected to temperature, that is to say, it has “sensitivity”. Originally I was (and to some extent still am) trying to understand why positive feedback in absorptivity doesn’t drive the atmosphere to unit absorptivity at 1.2 T_greybody, or rather, what limits there are on the functional relationship such that this does NOT happen. This seems relevant to the entire discussion on whether feedback from water vapor is net positive or net negative or if net positive, what the limits are on it such that Hansen’s “boiling seas” assertion fails to come to pass. (The latter is pretty easy, even in a single layer model — because the single layer gain is at most 1.2, and 1.2×255 = 306K, or 33 C, which is indeed hot for a mean temperature but far, far short of hot enough to boil anything.)
My secondary goal in this is to look at fluctuation-dissipation in a trivial physical model. One obvious flaw in the GCMs is that they individually fluctuate around their current smoothed GASTA prediction at an amplitude that is nearly twice as great as the actual obvserved amplitude of fluctuation, and fluctuate more more regularly than the actual climate, and have far too steep a rate of fluctuation growth compared to the regular climate. In other words, eyeballing the threads in 1.4 in AR5 SPM, they don’t JUST fail in the mean, they fail badly in their higher order moments. These moments represent their internal DYNAMICS, the way they handle forcings and positive/negative feedbacks. I’d like to try to understand in very simple terms what’s wrong here — it isn’t just “too much forcing” because when they overshoot the GCM mean it falls rapidly back across that mean and often dips almost all of the way back to the actual observed temperature — it goes DOWN too fast and too far. This suggests that they have the wrong GROSS behavior in their feedback terms, in the dissipation modes that cause fluctuations to grow and decay.
I’ve written a little snippet of matlab/octave code so far that actually does a nice job of solving the single slab model, and even gets the right behavior in the limits. In those limits it directly refutes the favorite argument of Joules/Joe Postma, that a properly implemented absorper/emitter atmosphere leads to runaway warming, just as it refutes HANSEN’S argument that (so far) suffiently positive climate sensitivity leads to runaway warming. The model is perhaps oversimplified, but I’m aware of its limitations and my goals are (I think) well within its limitations. My next goal is going to be to add some sort of delta-correlated stochastic noise in one of the very few parameters in the model — perhaps albedo or a_lw, the longwavelength absorptivity (or just to T_s itself) to make the system a set of Langevin equations. From that it is straightforward to compute the autocorrelation function for radiation only relaxation and see how feedback in a_lw affects things.
rgb
Don’t listen to Roy, Willis. Discovering stuff on your own is what makes you get up in the morning. It also makes you a much more interesting fellow than Joyless Roy.
What is also interesting is what happens at the 30C limit.
The x-axis is not the same as your previous Clouds regulate temperature article but I think the two combined show …
At the 30C sea surface temperature limit, clouds form and increase the reflection of solar radiance from about 25 W/m2 to 175 W/m2 in most of the scenarios. Solar irradiance at the surface falls by 150 W/m2 (an average of day and night – during the height of the day at 4:00 pm, this would be a very significant reduction in daytime solar radiation approaching 700 W/m2).
The outgoing long-wave also is impacted by this cloud increase at the 30C limit. It appears to me, the reduction in long-wave is about 125 W/m2 in most of the scenarios.
So, there you have it, the Cloud Feedback at the 30C limit (based on the eyeball method versus the actual numbers). The cloud increase at the 30C limit is truly a Negative influence. Reflecting 150 W/m2 of solar irradiance, holding in 125 W/m2 of long-wave.
Not a linear + 0.7 W/m2/C at this temperature but a very strong negative -25/W/m2/0-1C.
I can’t see what happens at the other sea surface temperature ranges, but we clearly have a complex non-linear function for the cloud feedback.
First, @daniel kaplan
“a 28*C span is about 10% of the Kelvin temperature of 300K. Outgoing LW radiation goes as the 4th power of the Kelvin temperature, so it should vary by about 40%. A variation from 200 to 300 W/m2 is about right.”
I appreciate that demonstration. Yes, it is correct not to think of the variation in linear terms.
@Willis
I want to comment on the 10 Deg tropics only. I see in all cases that the temperature you noted earlier on in your cloud formation time-of-day articles there is a swing in the trend of the blue dots. As the sea temperature rises there is a significant drop in LW and it is consistent through all seasons. The slope of the blue dots is definitely down-right with increasing temperature.
The only thing which can create that at ±10 latitude is a layer of clouds. Whether they are locally broken by thunderstorms punching through is a separate matter. But the blocking of LW has to be accompanied by a concurrent rise in SW reflecting off the top of the clouds, not so? Thus the total will remain about the same as is required. I say that because the alternative (heat is trapped and funneled in massive quantities under the clouds towards the poles) is untenable for such a thin atmosphere. I wouldn’t get far.
I am not sure if the data you are working from can detect the time of day or not. If it can’t, then maybe there is a data set elsewhere for some small region of the tropics.
If you had the same analysis by the hour, you should be able to see that the trend line of the blue dots changes during the day, with LW dropping rapidly as the visible clouds start to form. More specifically, they should be ‘IR-visible’ which could be sooner, and that would affect OLW. As the clouds are visible, that reflects SW insolation. Maybe there is an overlap or underlap of importance. Can’t tell.
A second parse is the sea temperature near land compared with the open ocean. I suspect there will be a land-effect in there. Pick one or there other and look for a clear difference. The ocean off west coast of Africa provides a very dry atmosphere in which water has to be gained. Very different west of India after the monsoons. I expect to see a later formation of clouds in the dryer air. The combined view would have a vertically thick line of dots from left to right which is exactly what you have produced.
Prediction: the LW will change with the time of day in those tropical areas with clear mornings, in the same manner as you have already observed for ‘cloudiness’. Hardly a surprise, but you have put some hard numbers on it. If you repeat the procedure with SW the blue dots will inflect the other way at 30°. Also not a surprise (unless there are surprises) because of unknown unknowns.
A couple of other charts to explain why the outgoing long-wave appears to be so similar.
The long-wave emitted by the tropics versus the poles is not actually that much different in W/m2 because the energy is related to the fourth power of the temperature.
The surface temps at the poles are still emitting around 200 W/m2 while the tropics should get up to 450 W/m2 (but obviously don’t given the OLR charts from Wills). This is because we are measuring the OLR from the troposphere where temps approach -18C or 240 W/m2.
http://s14.postimg.org/ck1mcrbwx/Surface_Temp_Longwave_by_Lat_W_m2.png
And then, if we are measuring from the sea surface only, well it does not vary that much across the globe. We get close to 32C is some places and sea water freezes at -1.9C. The sea ice can get colder than that but we have a much more constrained temperature range and more constrained emission of energy. The sea surface temperature is actually much higher than the land surface temperature (partly because Antarctica weights the land lower and there is less ocean at the poles because of this due to Antarctica). The Implied long-wave emitted by sea surface temps ranging from -1.5C to 34.5C (note this is not actually a linear line although it appears so in this range).
http://s24.postimg.org/kud839mxh/Sea_Surface_Temp_Longwave_W_m2.png
I think some of what Willis is observing is explained in http://www.kidswincom.net/CO2OLR.pdf. Radiation from clouds is the big rate controller. Think about how fast the temperature drops on a clear night with low humidity.
dp says:
October 8, 2013 at 10:38 pm
Upwelling and downwelling isn’t a 50/50 ratio. Most of the atmosphere is above the horizon so even some “downwelling” radiation is still aimed at the stars.
No you need to consider the geometry of the atmosphere it’s incredibly thin.
The earth’s radius is ~6370 km the scale height of the atmosphere is 8.5 km. Pick a point at 8.5km above the earth and calculate the angle subtended by a tangent to the horizon, you’ll find that the ratio of the upwelling/downwelling doesn’t vary much from 1 (i.e. 50/50).
Willis … interesting that you’d bring this up … I”ve been reading the crap out of this very topic because, it is evident from reading a lot of literature that OLR at the TOA is solely depending on the cumulative LW radiation being emitted, which = LW(SST) + LW (land) + LW (Atmosphere), where the contribution from the atmosphere is Total LW (atmosphere)-LW from the atmosphere that was absorbed from the ocean or land [ie., greenhouse effect]. As such, not all SW radiation absorbed by the ocean is going to be immediately available for the temperature equation. The ocean works kinda like a capacitor. No suprise .. EVERY Temp metric follows the ocean SST. Quite simply put, the primary driver of our atmospheric temperature is not CO2, but rather the ocean SST. .. it is NUMERO UNO.
The temperature equation needs to be changed [IMO] from such that S(1-a) is replaced by the above LW contributions. … LW(SST) + LW (land) + LW (Atmosphere),
The literature supports your pont regarding the drop off in OLR above a certain point. From the reading of the literature that I”ve seen, increased clouds is a significant damper on ocean OLR. 1) it is blocking short wave .. and 2) it is contributing to downwelling LR, thus decreaseing net ocean OLR.. .. and 3) as you said, aborbing upwelling LW from the ocean itself.
This same phenomenon is also the explanation for why you don’t see a linear relationship between OLR at the Pole vs the Equator. Clouds increase as you move towards the equator, thus the same muting effect that you noted at 30C surface temp is operating throughout the transition of latiitude.
Due to simplified diagrams it is sometimes thought that outgoing LW radiation is a vertical process. It is not, the radiation is constantly absorbed and re-emitted, thermalized and de-thermalized. The process is more like diffusion. As such, the radiation measured at the equator could have originated at one of the poles. I think this is one of the reasons for the relative flatness of the line. That along with the fact that most of the radiation comes from higher altitudes. This works in conjunction with the heat flow from general circulation but works constantly to try and even out the temperature of the atmosphere, thus stabilizing the structure.
In addition, the frequencies start to “blur” as part of the diffusion process. That is, the energy radiated from the surface in bands that CO2 absorb can be changed into bands absorbed by water vapor, clouds, etc. … and vice versa. While more energy may be absorbed with some added CO2, the added CO2 also assists in diffusing the energy already absorbed. IOW, the process is made more efficient and the result is not so much a warmer atmosphere but a more stable atmosphere.
Good comments from Richard M
If someone looks at the IR of a hurricane the most striking thing is how cold and high it is. The other thing they may know is that the lowest pressure comes with the highest column of air. The center of a hurricane rises miles into the stratosphere.
Humid air is less dense than dry air and contains more heat for a given temperature and volume. A hurricane (water vapor) transports warm humid air from the surface high into the atmosphere but the expansion of the air translates into very cold air, hence a lower IR TOA emission.
An atmosphere in equilibrium is Isothermal. GHG’s create a lapse rate and water vapor erases the lapse rate.
You want to know what’s really amazing?
Over three years ago here on WUWT, a proposal was posted here about using shipping containers as emergency housing in earthquake-devastated Haiti, which is also known for being frequently tropical storm-devastated.
http://wattsupwiththat.com/2010/01/20/just-crazy-enough-to-work-shipping-containers-for-emergency-shelters-in-haiti/
Today it is reported shipping containers are to be used for “emergency housing” in London, where there is a chronic shortage of cheap rents. Come with full plumbing, ‘leccy, bi-directional heat pumps, burners for cooking. Stackable housing, deploy where needed. Imagine these replacing FEMA trailers in the US.
http://www.dailymail.co.uk/news/article-2450762/Shipping-containers-rented-London-homes.html
I’m posting this here as Mr. Eschenbach has been known to appreciate innovative solutions using minimal resources.
I feel like I must not be understanding something. How can so much Long Wave radiation be escaping high latitudes in December, when there is hardly any sunshine? Is it transported north by Hadley, Ferrel and Polar cells? Is it latent heat from oceans that are relatively warmer than the air, and whose evaporation creates huge North Atlantic and North Pacific gales? (I’ve read something like 23% of outgoing long wave radiation is via latent heat exchanges.)
One final question, before I halt my public display of ignorance. Is this CERES satellite able to differentiate between the origins of the heat it is sensing, or does it just measure heat in general?
(I’m most interested in the difference between heat lost by the Arctic Sea when it is covered by ice, versus when it is open water. Is the CERES satellite capable of measuring something like that?)
Willis, I need a clarification here. When you say TOA upwelling, do you mean radiation that is emitted from the top of the atmosphere only, or all the radiation emitted as measured at the top of the atmosphere?
Thanks.
I am having difficulties posting a comment. An add appears over the e-mail and username and blocks the access. I am posting this comment from my wife’s computer. Is anyone else having this problem?
Willis, considering the data set that you are using, can you use this data and the cyclic variation of carbon dioxide in the atmosphere to calculate the sensitivity of the climate to carbon dioxide concentrations in the atmosphere?
John,
I’ve checked the sensitvity of OLR by regions and find it is very sensitivity to moisture content (water, gas, or ice) but not to CO2. http://www.kidswincom.net/CO2OLR.pdf.
Roy Spencer says :
“Willis, if you would read up on what we already know about this stuff, you would not be so perplexed.”
Claude Harvey says :
“Don’t listen to Roy, Willis. Discovering stuff on your own is what makes you get up in the morning. It also makes you a much more interesting fellow than Joyless Roy.”
I agree with both comments, but I tend to lean towards Joyless Roy on this topic.
Roy Spencer says:
October 9, 2013 at 4:23 am
Dr. Roy, I listed three, well actually four puzzling things to me:
The first is that despite the ocean being much colder near the Arctic in July than it is at the Equator, the TOA upwelling longwave radiation (ULR) is nearly constant from Arctic to Equator. Why doesn’t the ULR drop with the surface temperature as it does during other months?
The second is that nowhere over the ocean do we see more than about 300 W/m2 of TOA upwelling LW radiation. Why the limit?
The third is that from Arctic summer to Arctic winter, which means from full sun to no sun at all, the ULR in the northernmost and coldest oceans varies by only about 20 W/m2. Why so little?
The fourth is that unlike in the northern hemisphere, in the southern hemisphere the upwelling LW changes very little from month to month. Why the difference from the NH, which does vary on a monthly basis?
Perhaps you could send us links to the previous studies that you say explain all of these questions. That would be more useful than a drive-by posting … you keep saying that all of this is known and well-studied.
So if you’d be so kind as to give us the links to the relevant studies, that would be much appreciated.
All the best,
w.
sophocles says:
October 9, 2013 at 12:59 am
The actual split of the ocean is Southern Hemisphere, 57% and Northern, 43%. So while there is an imbalance, it’s not that large.
While that is assuredly true … why wouldn’t that circulation vary from the Antarctic summer to their winter?
They help, but I don’t think they explain the overall thermal stability of the SH as compared to the NH …
w.
Ahh. The science is settled. Again.
(Oh. OK. Sarc. Did anyone guess?)
Well done Willis! More queries, more areas where it is clear that, after all, not all the science is fully settled.
I don’t have anything like the expertise to otherwise comment, but do appreciate my eyes being opened on this.
Auto
Willis: I mean, the upwelling radiation from the surface (solid black line) increases by 50% from the coldest to the warmest areas
that’s calculated from a model like Stephan-Boltzman, or measured? And how accurate is the model for open water?
Your empirical finding is intriguing no matter what the answers to my questions? One would expect the upper troposphere to be warming more at those higher surface tempeeratures, or else the upward radiation maintaining the water vapor in its vapor state longer, or both. (probably other possibilities I have not thought of.)
Oceans & seas make up around 81% of the SH, while only about 61% of the NH is covered by seawater, IIRC.
Roy Spencer: Willis, if you would read up on what we already know about this stuff, you would not be so perplexed.
With respect, could you provide us a few bullet points describing what here was already known, and the references? This is a good place whenever you want to provide us denizens with information that we have not come across in our other searches. I follow most links to information, and others do as well.
Edim says:
October 9, 2013 at 1:07 am
I do so enjoy a man who shows up with actual numbers, thanks, Edim.
Global average TOA upwelling longwave in the CERES 10-year dataset is 239.6 W/m2
Some 40 W/m2 is known to go through the “atmospheric window”. That’s about 16%. About 26 W/m2 (11%) comes from the clouds. The rest (73%) comes from the atmosphere.
Mmmm … not so. The sources of energy in the atmosphere are:
Absorbed from sunlight: 68 W/m2
Sensible heat (conduction): 22 W/m2
Latent heat (evapo-transpiration): 76 W/m2
Radiation: 340 W/m2
The non-radiative gains from the surface (sensible plus latent heat) only total about 100 W/m2. This is only about 20% of the heat gained by the atmosphere.
You might enjoy my reworking of the Kiehl/Trenberth global energy budget. Unlike theirs … mine balances.
w.
The puzzling aspects of the latitudinal variation of OLWR are most likely the consequence of the homogenizing effect of entropy. At altitudes from which such radiation escapes to space, there is little diurnal and seasonal variation as well. Such strong homogenization involves much poleward advection of heat and turbulent mixing, not just the vertical transport commonly portrayed.
Willis,
Edim is correct, in terms of net flux in and out, most of the energy being radiated from the top of the Hadley, Ferrel and Polar tropospheric circulation cells as LWIR was acquired by surface conduction and the release of latent heat.
This net flux diagram is slightly less of a travesty than Trenberths effort –
http://upload.wikimedia.org/wikipedia/commons/5/50/Breakdown_of_the_incoming_solar_energy.svg
Radiative gases being able to emit LWIR from the top of the atmosphere plays a critical role in tropospheric convective circulation, allowing air masses entrained in the Hadley, Ferrel and Polar cells to lose buoyancy and subside.
Altering the concentration of these gases in our atmosphere alters the speed of tropospheric convective circulation (there would be no circulation without them), and thereby the speed of mechanical energy transport away from the surface. Mechanical energy transport includes the movement of energy from latent heat and surface conduction to the upper atmosphere.
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). Poorly radiative gases stagnated at altitude would then super heat, just as in the thermosphere, and boil off into space. (Dr. Spencer did not consider this). Our atmosphere is therefore cooler due to radiative gases.
There is a slight radiative green house effect on earth, most notable over land at night, but the net effect of radiative gases in our atmosphere is atmospheric cooling at all concentrations above 0.0ppm.
Please do not fall in the the old Trenberth energy budget trap to calculate gross heat transfer for radiation only.
Do as every engineer do, calculate NET heat transfer for atmosphere by radiation as for all other way of heat transfer and You find the atmosphere NET heating are only 339-321 +13 = 31 W/m2 by radiation.
The reason for this? GHG efficiently block heat transfer by radiation. Call it back radiation or whatever but it is still only 31W/m2 by radiation. Net. Ask any engineer.
22W/m2 by sensible heat, 76W/m2 by latent heat and 31 W/m2 by radiation and 68 W/m2 direct by sun. The atmosphere is heated only by 31/197 or about 16% by LW radiation.
When You use this net radiation values will You also understand why it is so important for IPCC to use big number in radiation to fool people to get the impression that the atmosphere is heated by LW from ground. It is not. And it is because of the efficiency of GHG.
There is Your answer why surface temperatures do not reflect in outgoing LW at TOA.
The atmosphere is cooled 100% or with 237 W/m2 by radiation. From my view is the atmosphere radiative heat balance LW out 237 W/m2 and 31 W/m2 in. Net radiative heat transfer for the atmosphere are -206 W/m2 .
The atmosphere is cooled by GHG from a heat transfer perspective.
Konrad 1:57pm: “This net flux diagram…”
The diagram you link is in units of power.
“Without radiative gases…”
Refer to the chart of earth’s PW of power in and power out that you link. If infrared active gas ppm in earth’s atm. tends toward zero, then what values would the 33 and 26 PW power “absorbed by atmosphere” (~orange arrows) tend toward in that chart?
“You might enjoy my reworking of the Kiehl/Trenberth global energy budget. Unlike theirs … mine balances.”
How much sunlight is diffused- it gets to surface but not in direct path?
coldlynx says:
October 9, 2013 at 2:11 pm
……..
The atmosphere is cooled by GHG from a heat transfer perspective.
======================
Interesting. I have reasoned with this frequently over the past couple of years. Never commented with regards to the heat transfer from non-radiating gas to that of a radiating gas. You are the first to address this and matches my line of reasoning. Good to see someone put numerical values to it. I hope to see this discussed more in depth.
Robert Brown: “My secondary goal in this is to look at fluctuation-dissipation in a trivial physical model. One obvious flaw in the GCMs is that they individually fluctuate around their current smoothed GASTA prediction at an amplitude that is nearly twice as great as the actual obvserved amplitude of fluctuation, and fluctuate more more regularly than the actual climate, and have far too steep a rate of fluctuation growth compared to the regular climate. ”
English, please, Dr. Brown. Or maybe math. Either one (but preferably both, one describing the other) will do. Please understand that, although many–perhaps most–of us are laymen, a lot probably did fulfill a college math requirement, Undoubtedly English, too. Jargon, not so much.
If your goal was to frighten the natives with the abstruse nomenclature, you probably achieved it with some subset of the readership. If it was to inform, I have my doubts.
Maybe a little off topic but everyone else is riding their hobby-horse
The whole concept that absorbed/emitted radiation
changes the temperature of a molecule is flawed. I am
specifically refering to absorption lines. Photons are
not particles of heat. Photons are energy particles. In
our day to day life we connect heat to energy but in the
case of molecules the lines indicate a mechanical change
to the structure of the molecule, ie stretching,
rotating, shifting of electrons etc.. 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. There
might be a delay in energy transfer in the time scale of
milliseconds but that doesn’t matter. The atmosphere is
like an energy conveyer belt. Energy comes in at one end
and leaves at the other to space. If there is an
increase or decrease in the energy the belt adjusts.
Don’t believe me? Look at electron drift in conductors.
The electron you pump into the system from the power
source is not the same electron that does the work. The
energy from the sun that we receive daily was created
millions of years ago in the centre of the sun.
You don’t believe that energy can be absorbed without
changing temperature? If no, then explain latent heat to
me. Water at 100 deg C and steam at 100 deg C.
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.