Guest Post by Willis Eschenbach
The CERES dataset contains three main parts—downwelling solar radiation, upwelling solar radiation, and upwelling longwave radiation. With the exception of leap-year variations, the solar dataset does not change from year to year over a few decades at least. It is fixed by unchanging physical laws.
The upwelling longwave radiation and the reflected solar radiation, on the other hand, are under no such restrictions. This gives us the opportunity to see distinguish between my hypothesis that the system responds in such a way as to counteract changes in forcing, and the consensus view that the system responds to changes in forcing by changing the surface temperature.
In the consensus view, the system works as follows. At equilibrium, what is emitted by the earth has to equal the incoming radiation, 340 watts per metre squared (W/m2). Of this, about 100 W/m2 are reflected solar shortwave radiation (which I’ll call “SW” for “shortwave”), and 240 W/m2 of which are upwelling longwave (thermal infrared) radiation (which I’ll call “LW”).
In the consensus view, the system works as follows. When the GHGs increase, the TOA upwelling longwave (LW) radiation decreases because more LW is absorbed. In response, the entire system warms until the longwave gets back to its previous value, 240 W/m2. That plus the 100 W/m2 of reflected solar shortwave radiation (SR) equals the incoming 340 W/m2, and so the equilibrium is restored.
In my view, on the other hand, the system works as follows. When the GHGs increase, the TOA upwelling longwave radiation decreases because more is absorbed. In response, the albedo increases proportionately, increases the SR. This counteracts the decrease in upwelling LW, and leaves the surface temperature unchanged. This is a great simplification, but sufficient for this discussion. Figure 1 shows the difference between the two views, my view and the consensus view.
Figure 1. What happens as a result of increased absorption of longwave (LW) by greenhouse gases (GHGs), in the consensus view and in my view. “SW” is reflected solar (shortwave) radiation, LW is upwelling longwave radiation, and “surface” is upwelling longwave radiation from the surface.
So what should we expect to find if we look at a map of the correlation (gridcell by gridcell) between SW and LW? Will the correlation be generally negative, as my view suggests, a situation where when the SW goes up the LW goes down?
Or will it be positive, both going either up or down at the same time? Or will the two be somewhat disconnected from each other, with low correlation in either direction, as is suggested by the consensus view? I ask because I was surprised by what I found.
The figure below shows the answer to the question regarding the correlation of the SW and the LW …
Figure 2. Correlation of the month-by-month gridcell values of reflected solar shortwave radiation, and thermal longwave radiation. The dark blue line outlines areas with strong negative correlation (more negative than – 0.5). These are areas where an increase in one kind of upwelling radiation is counteracted by a proportionate decrease in the other kind of upwelling radiation.
How about that? There are only a few tiny areas where the correlation is positive. Everywhere else the correlation is negative, and over much of the tropics and the northern hemisphere the correlation is more negative than – 0.5.
Note that in much of the critical tropical regions, increases in LW are strongly counteracted by decreases in SW, and vice versa.
Let me repeat an earlier comment and graphic in this regard. The amounts of reflected solar (100 W/m2) and upwelling longwave (240 W/m2) are quite different. Despite that, however, the variations in SW and LW are quite similar, both globally and in each hemisphere individually.
Figure 3. Variations in the global monthly area-weighted averages of LW and SW after the removal of the seasonal signal.
This close correspondence in the size of the response supports the idea that the two are reacting to each other.
Anyhow, that’s today’s news from CERES … the longwave and the reflected shortwave is strongly negatively correlated, and averages -0.65 globally. This strongly supports my theory that the earth has a strong active thermoregulation system which functions in part by adjusting the albedo (through the regulation of daily tropical cloud onset time) to maintain the earth within a narrow (± 0.3°C over the 20th century) temperature range.
w.
As with my last post, the code for this post is available as a separate file, which calls on both the associated files (data and functions). The code for this post itself only contains a grand total of seven lines …
Data (in R format, 220 megabytes)
Thank you Willis,
For over ten years, being an educated sort of layman, I have been trying to explain the increased temp/increased water vapor/increased Albedo, equilibrium scenario. Your post has given me one more arrow in my quiver to further state what I feel as the obvious (in my non-scientific opinion), That is the state of equilibrium will always be the result of increased surface absorption/ reduced radiative reflection, for whatever reason.
Is this the same as the Iris effect? Prof Richard Lindzen
Bad amatuer…BAD BAD AMATUER…shades of Tom Edison, Michael Faraday, and (horrors) the Wright Brothers. Shame on you for making primates out of the Phd’s. Your punishment, watching Lady Gaga, Al Gore, and Ahhhnold Schwartneger give talks on AWG. (Wait, that’s right, under the current administration, “enhanced interrogation” is not allowed. I guess you get by this time!)
Cool Willis. Thanks for your work.
Very interesting. I’m not surprised at the result. A large fraction of reflected SW outgoing suggests dense clouds with high tops, which in turn are unusually cool, and which as a result have a smaller than average LW outgoing.
Here is what I see as two issues to examine.
1) This data doesn’t related directly to the problem of increasing GHGs because that is a long-term trend. This data, I think, exhibit the effect I summarize above, which may or may not result from what you propose. How can you demonstrate that the different time scales involved (GHGs versus your data) are not important?
2) You have shown the correlation, but what can you do to establish causation? You need to show that there is a time lag or something–effect follows cause.
Maybe there is some clarification from the observation of “yellow” areas that seem as if they are pressed against the west sides of continents. Maybe this is a location with different cloud formation properties than other ocean.
I’m a little concerned that -0.65 is still a weak correlation, but then weather data are typically noisy.
The CERES SW window really has a lot of near IR with it (0.3 to 5 micron) and the IR window is close at 8-12 micron, so it’s interesting that you find the 2 bands so negatively correlated.
Maybe a better correlation exists in the more raw data, because you are offered temporally smoothed monthly data. The radiation could well change from orbit to orbit and show as smeared in the final assembled data. Can you get pairs of simultaneous point observations to check this?
Shouldn’t the right hand box of Fig 1 show 390W/m2 ?
Willis
Can you please define the terms SW and LW (I know that it is short wavelength and long wavelength). What I want to know is what is the definition of the wavelengths involved.
Any increase in CO2, and CH4 must, by definition, have an increased absorption waveband and I have yet to see this quantified adequately. Also, from the equations involved, absorption is both temperature and pressure dependent, I have never ever seen any of these models deal with this type of dependency.
Thanks, Willis. Nice work, very clear, however, your results are showing a negative feedback mechanism that tends to stabilize the system. It does not directly address the effect of adding greenhouse gases to the atmosphere, or have I missed something?
bones, he addresses the effect of adding greenhouse gases indirectly. We know they have been added, but the negative correlation between LW and SW persists.
I believe your third cartoon “My View” should have 390 as the surface radiation.
Interesting post Willis
Charlie A says: January 7, 2014 at 9:35 pm
Shouldn’t the right hand box of Fig 1 show 390W/m2 ?
Yes, Charlie is correct. To correspond to Willis’ narrative that an increase in GHG causes a change in albedo rather than a change in surface temperature, the upward LW radiation from the surface should be the same as the “Equilibrium” left panel before the increase in GHG. The GHG absorption in the left panel is 150 W/m2 (ie, 390-240), and is 152 W/m2 is the middle panel that has increased GHG, an increase of 2 W/m2. The right panel is supposed to have the same GHG absorption as the middle panel, but with the incorrect number it has 392-238 = 154 W/m2, or an increase of 4 W/m2 over the left panel case. Correcting the upward LW to 390 W/m2 in the right hand box will make the increased GHG absorption over the left panel case equal 2 W/m2.
dalyplanet says:
January 7, 2014 at 10:21 pm
[Thanks, fixed. -w.]
You have a major error here. You have conserved energy flux, whereas you should conserve energy. The area of the incoming flux is the cross-sectional area of the earth. The area of outgoing flux is the earth’s surface area, which is a factor 4 smaller.
Willis,
with regard to the cloud thermostat, the time of day that clouds form is a factor even if the amount of cloud is only marginally increased. Earlier cloud formation leads to greater cooling even if cloud mass is not greatly increased.
Increased radiative gases should cause clouds to form a few minutes earlier after dawn over the oceans in the ITCZ.
Been puzzling lately about an aspect of the greenhouse effect as taught me in college many solstices ago. The story was that greenhouse glass (or gas) was permeable to shortwave incoming radiation but blocked outgoing longwave , and that the shortwave was somehow “converted” to longwave after it was absorbed inside.
Being young and impressionable and knowing well how hot my car got in Davis summers when the windows were closed, I was convinced.
Materials generally emit radiation wavelengths according to their temperature, but different materials have very distinct preferences for wavelengths and tend to both absorb and emit in the same bands. Outside these bands they seemingly ignore the radiation.
How then does a material convert shortwave to longwave?
Water (both surface and clouds), water vapor, and ice all have similar optical properties. they just luuuuv longwave radiation. CO2 loves it as well. They don’t care a fig about shortwave. Except for strong reflectance from clouds in the visible range (an unrelated property), they let it pass through.
All this may be a propos in a roundabout way because to examine the relationship between reflected shortwave and “upwelling” longwave, one must consider the sources. About half of TSI is longwave in the first place. The clouds, water vapor, atmospheric ice, and greenhouse gasses catch it and start flinging it around. The ocean surface catches all that comes its way in the first millimeters and flings it back.
If the extreme negative correlation in the tropical oceans means greater cloud reflectance and less escaping longwave, it could be that the LW escape is short circuited in a more intense photon food fight between the ocean and clouds and the reflection is incidental.
Unless you can explain to me how SW is “converted” to LW…
phillipbratby says:
January 7, 2014 at 10:42 pm
In the CERES data, both the incoming flux and the outgoing flux are averaged 24/7 over their particular gridcell. They are not general measurements of the total global flux. As a result, there is no such error as the one you imagine.
And in general in other datasets, all incoming and outgoing fluxes are calculated on a 24/7 basis, and are adjusted for the situation that you mentioned.
Scientists may be wrong, and often are. But when you think you’ve uncovered a “major error”, something really obvious, well, you should check your facts very carefully before uncapping your electronic pen …
w.
I also have a layman’s question that I’m sure someone has the answer to but I haven’t noticed it being discussed. The simplified explanations of “the Greenhouse Effect” talk about the Earth absorbing incoming solar SW radiation and emitting LW radiation, some of which is absorbed by “greenhouse” gases such as water vapor and carbon dioxide, which retards the escape of this LW radiation into space and thereby warms the Earth. My question concerns incoming solar LW radiation. Common sense suggests that greenhouse gases in the atmosphere also absorb incoming LW, thereby preventing it from reaching and warming the ground. If the concentration of greenhouse gases rises, they should absorb more of this incoming LW and prevent that from reaching the ground, resulting in cooling.
I’d like to know whether the total amount of LW at frequencies that can be absorbed and emitted by CO2 reaching the top of the atmosphere from the Sun is greater than the total emitted from the Earth’s surface over an equivalent period and whether this could lead to increasing “greenhouse” cooling rather than warming. And I’d like to know how the absorption and emission of this radiation is accounted for by conventional atmospheric greenhouse theory.
Where’s the non-radiative surface cooling by the atmosphere?
http://pmm.nasa.gov/education/sites/default/files/article_images/components2.gif
The non-radiative fluxes dominate.
Surface heat exchange (cooling side)
Convection and evaporation (sensible and latent): 59%
Radiation (incl. directly to space): 41%
Sorry, I have to ask this. How does CO2 absorb long wave radiation from the surface?
CO2 in the atmosphere is warmed by kinetic collisions with other molecules to local air temperature. The properties of CO2 indicate that the CO2 will be RADIATING over some 3,800 lines covering 13 to 17 microns. This same band of radiation is emitted from the surface.
If the CO2 happened to absorb some of that radiation when it has already emitted an equivalent amount of radiation then there will be no change to the energy levels in the CO2.
My understanding is that the surface does not emit in 2.7 and 4.3 micron bands so there is no effect there.
Please, just what energy is CO2 absorbing from the surface? Reflected sunlight? I really would like to know as all my studies just leave me more baffled.
Willis said:
“When the GHGs increase, the TOA upwelling longwave radiation decreases because more is absorbed. In response, the albedo increases proportionately, increases the SR. This counteracts the decrease in upwelling LW, and leaves the surface temperature unchanged”
All my work since 2008 has been based on that proposition and I have stated it multiple times in multiple locations.
Where we differ is that I see the ultimate determinant of the set point surface temperature as atmospheric mass held within a gravity field and irradiated from an external source.
Is the reason for that difference that Willis still gives undue prominence to the assumed need for GHGs to initiate the necessary convective overturning ?
It isn’t a matter of ‘pressure’ since ‘pressure’ is merely a proxy for the combined effect on density of mass and gravity.
It is varying mass densities caused by uneven surface heating that sets up the convective circulation which then applies the negative system response whenever the combined thermal effect of radiation and conduction goes out of line with the amount of energy required to maintain radiative balance for the whole system.
GHGs and especially water vapour are merely lubricants for the convective process.
The visible climate response from our perspective is shifting climate zones but the effects of variations from sun and oceans are so huge that we could never identify our miniscule contribution.
This post from Willis is the ultimate logical conclusion to be derived from his initial thermostat hypothesis (which was limited to tropical convection) but still requires recognition of the physical processes behind it all.
This is good demonstration Willis. Probably the most direct evidence yet of regulation happening.
Perhaps a finer colour scale would help the colour guide jumps from -0.6 to -1 which is a huge difference and makes it a but hard to judge how well it correlates.
I’m not surprised though , this is very much in line with what my volcanic stack plots showed (though this is much more concrete proof). I showed it was mainly tropical ocean with ex-tropics showing less recovery and stability. I also showed NH was less stable and linked this to larger land area.
The volcanic data is a nice complement to this though because it shows the response to a strong and specific perturbation, not some hypothetical degree of centennial scale change.
http://climategrog.wordpress.com/?attachment_id=310
What did surprise me in your graph is four decorrelated areas against the major continents. The Peruvian region is readily understood as upwelling cold water of La Nina providing a strong (non radiative) external input the disrupts the broader correlation.
However, the other three did surprise me, seeming just a clear and strong.
There would seem to be a relationship with the major ocean gyres pulling down colder polar waters into the loop. This again would suggest that the feedback is primarily sensitive to impinging radiation than SST itself.
I think these four zones that you have found demonstrate and importan phenomenon and should provide key insight into how this regulator works.
Nice work.
”In the consensus view, the system works as follows. When the GHGs increase, the TOA upwelling longwave (LW) radiation decreases because more LW is absorbed. In response, the entire system warms until the longwave gets back to its previous value, 240 W/m2. That plus the 100 W/m2 of reflected solar shortwave radiation (SR) equals the incoming 340 W/m2, and so the equilibrium is restored.”
While this is perhaps the most succinct explanation of the consensus view I have ever seen it glosses over several key points that expose some of the additional problems with the view:
In the consensus view, the system works as follows. When the GHGs increase, the TOA upwelling longwave (LW) radiation decreases and downwelling IR increases because more LW is absorbed. The increased downwelling radiation decreases the surface net radiation transfer to the atmosphere by radiation. Assuming no other energy transfers from the surface to the atmosphere increase, the surface warms and due to the Stephan-Boltzmann Law must emit more radiation. The entire system warms until the longwave gets back to its previous value, 240 W/m2. That plus the 100 W/m2 of reflected solar shortwave radiation (SR) equals the incoming 340 W/m2, and so the equilibrium is restored.
This portion seems to be shared by both views:
”the TOA upwelling longwave (LW) radiation decreases because more LW is absorbed”
Is there any real world evidence for this?
Another view:
When GHGs increase, both the TOA upwelling longwave (LW) radiation and downwelling longwave (LW) radiation increase because more LW is absorbed therefore more LW is emitted, not being a black or grey body GHGs emit what they absorb* (as opposed to emitting in proportion to their temperature). The increased downwelling radiation decreases the surface net radiation transfer to the atmosphere (slows the cooling) by radiation causing more energy to be transferred to the atmosphere by other processes like evapotranspiration thus keeping the surface temperature relatively unchanged since it is temperature gradients that drive heat transfer not radiation balances. The increased water cycle activity (i.e.: evaporation) increases the albedo of the atmosphere decreasing the solar energy absorption thus leaving the temperature of the atmosphere relatively unchanged as well (the increase in LW is offset by the decrease in SW). So, if there were a panel in figure 1 for this view the numbers would be around 101,241, & 390.
* More technically correct would be to say they may emit IR due to energy gained by absorbing IR or through collisions depending on a host of variables.
I favour your explanation. I have always had grave doubts about the claimed amplification of CO2 warming by water vapour since this would be potentially dangerous for our water planet. Any forcing that raised the temperature and resulting evaporation could trigger runaway warming by means of this positive feedback loop. Given that our climate is remarkably stable, positive feedback seems very unlikely.
Water vapour is a GHG, so there must be another mechanism to limit or prevent the amplification scenario. This is cloud formation which acts as a cooling sun shade through reflection of incoming shortwave. Furthermore, cloud formation removes water vapour GHG from the atmosphere. This, I think, is the GHG warming limiter or thermostat.
I guess the GHG induced warming increases water vapour but also convection, transporting the vapour to higher in the atmosphere where it condenses to form clouds. In a dynamic process, this may not even be noticeable.
Dear Willis, very fine work. Thanks