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)
Willis Eschenbach says: January 8, 2014 at 10:35 am
“Huh? Typo on your part? You can’t both scatter and absorb 100%.”
Not perfectly expressed, but the idea is right. Here is the vander Hulst relation. For long wavelength, Q is 2. That is the sum of absorption (1) and scattering, as a fraction of absorption. The amount of incident light scattered is equal to that absorbed. That includes light that was not going to hit the particle directly.
Nick Stokes says:
January 8, 2014 at 12:15 pm
Gosh, you mean that LW is equal to SW + LW – SW? Gotta say that’s a real shock, right up there with 4 = 7 + 4 – 7 … what’s your point?
You say that incoming solar is about equal to upwelling SW + LW. While this is generally true for the planet when averaged on a yearly basis, it is not true in any sense for the individual gridcells. On a gridcell y gridcell basis, the range for (solar – longwave – reflected) ranges from -200 W m-2 to + 200 W m-2. Not only that, the interquartile range is from -110 W/m2 to +60 W/m2 … and you call that “pretty much balances”???
Run the numbers first before bothering us with your theories, there’s a good fellow. Right now, I’m doing your homework for you and finding your errors, which doesn’t do your reputation any good.
w.
Willis, I am trying to better understand your position based on the diagram you have offered. It *appears* that:
Your expectation is that any change in the strength of the planet’s greenhouse effect is reacted to directly by the planet’s albedo, in an equal and opposite direction, the end result being that the surface temperature will be the same as it was before. But having left the passage of time out of this analysis leaves the question whether you expect this to occur instantaneously or…? On some unspecified timescale? At any rate: based upon this it appears your contention is that: the same absolute surface temperature could sustain a higher or lower albedo, and the albedo is, in effect, determined by the strength of the greenhouse effect, not the surface temperature. Is this correct?
Interesting to see how the various commenters are beginning to diverge.
Willis is right in his observations and he realises the practical implications but IMHO still needs to do a bit more thinking to see the mechanisms involved. He is currently ‘stuck’ on GHGs as being necessary for a convective cycle whereas they are not needed at all. They just help to ‘lubricate’ the convective cycle.
The usual ‘warmist’ proponents are making more and more picky points about irrelevant aspects and are avoiding the main issues.
Some, like rgb, are getting very close to envisioning the reality. He sees the effectiveness of the hydrological cycle as a system lubricant but has yet to realise that the convective cycle can do the job for a relatively non-radiative atmosphere even if the albedo changes can only be effected by wind kicking up dust from a dry surface.
The simplest description is that the sum of convection and radiation must leave the correct amount of thermal energy (KE) at the effective radiating height to match energy in with energy out. Otherwise no atmosphere.
If it does not, then convection moves energy around (KE to PE and back again) as necessary and the less radiative gases there are in an atmosphere the harder the convective cycle has to work to maintain equilibrium.
The convective cycle will alter albedo by whatever means are available even if that involves merely violent winds whipping up dust from the surface as seen on Mars.
Interesting times 🙂
Bulsit says:
January 8, 2014 at 12:15 pm
Dear heavens, the fog is thick out there today.
Yes, Bulsit, there is an emissivity for gases … but no, it’s not 0.002. For any particular gas, he emissivity depends on the frequency of the radiation, and varies from 0 to about 1. See the flux emissivity tables and discussion here.
And don’t try to impress us with your wisdom until you have some. Your claim is patent nonsense that any serious researcher would just laugh at.
w.
Willis Eschenbach says: January 8, 2014 at 2:06 pm
” what’s your point?”
The point is that what you have described as LW is not an independent measure of upwelling LW, according to CERES. It is obtained by subtracting measured SW from measured total upwelling. And since total upwelling is constrained to balance TSI (cons en), with temporary variations due to environmental heating/cooling and spatial fluctuations due to heat circulation, the variation of “LW” is mainly determined by SW, and so must correlate (negatively).
That’s nice. With the seasonal effects removed, I was surprised by the large size of the correlation.
Greg Goodman says:
January 8, 2014 at 12:17 pm
Greg, you came in the door and rather than saying something like “I didn’t bother reading your code, so I have a question about rounding”, which would be passable, you said my numbers were “not too accurate” and that I had engaged in “crude rounding” … both of which were nonsense and a complete fabrication on your part. I did neither one.
I’m just saying that if you don’t know something, ASK. You didn’t have a clue what the “roundto” variable did, but despite that you accused me of using “crude rounding” … and all the while, my legend numbers were accurate to 100 decimal places.
You should ask if you don’t understand, because falsely accusing me of putting out inaccurate numbers and using “crude rounding”, when NEITHER ACCUSATION CONTAINED A SHRED OF TRUTH, will not win you any bonus points.
Best regards,
w.
Nick Stokes: The point is that what you have described as LW is not an independent measure of upwelling LW, according to CERES. It is obtained by subtracting measured SW from measured total upwelling. And since total upwelling is constrained to balance TSI (cons en), with temporary variations due to environmental heating/cooling and spatial fluctuations due to heat circulation, the variation of “LW” is mainly determined by SW, and so must correlate (negatively).
Clearly that is an important issue that must be resolved. Willis, is Nick correct about how LW is measured?
Willis:
You’re on the right track in recognizing that increased LWIR absorption by the atmosphere need NOT necessarily lead to increased surface temperatures. The “homeostatic” regulating mechanism, however, is not likely an increase in planetary albedo, as you speculate in apparent contradiction of your own findings from CERES data. Far more fundamental is the reduction in the insolation available for thermalization near the surface. A dusty atmosphere reduces the power density by tens of W/m^2 and a cloudy one by hundreds, thereby cutting the core supply of solar energy to the surface. As I’ve been trying to get across in my comments on your series of recent posts, what happens high aloft in the planetary “energy budget” is not the critical factor. It’s the near-surface processes that matter most!
Nick Stokes says:
January 8, 2014 at 2:18 pm
Thanks, Nick. I thought I went over this. Yes, the LW is equal to SW + LW – SW.
And yes, 4 is equal to 7 + 4 – 7 … again, what is your point? Does that make 4 the wrong answer?
No, no, no, there is no constraint that either the gridcells or the total radiation balance at any instant that we might care to measure them. The calculation LW = Overall (LW+SW) – SW is done on the instantaneous measurements, not on global annual averages. Thus, there is no constraint.
The CERES data doesn’t measure total radiation. It only measures gridcell by gridcell radiation. And that data is not constrained in the slightest, as I pointed out.
If your claim were true, then the LW-SW correlation would be the same everywhere, because it would be constrained … but it isn’t that way at all. Instead, the gridcell correlation ranges from -0.97 to + 0.25, and the gridcell “balance” ranges from -200 to + 200 W/m2 … so please, give up the claim that the gridcells are “constrained to balance”.
Finally, month-by-month the net TOA data are also characterized by imbalance, not balance. In June the net is minus ~10 W/m2, and in January it’s about -10 W/m2.
So at no point in time are either the individual gridcells or the overall total constrained to balance.
w.
here is the graph rescaled to clarify the range -0.5 to -1 . This is not supposed to be better or replace fig 2 but give a more detailed look at part of it. A finer colour scale over the range +0.25 to -1 would be better.
http://i39.tinypic.com/2crqzhu.png
Now we need to know what sort of correlation coeffs can considered significant.
Each cell has 13 years of monthly data. but this has been ‘deseasonalised’ which is crude kind of 12m low-pass filter and effectively reduces the number of degrees of freedom by a factor of twelve, so we are back to 13 independent readings.
with N=13:
-1.0/N+2.0/sqrt(N) = 0.48
So anything out of the red can be considered with 95% confidence to show correlation that is non random. So that means that the four regions close to land that were comment on by myself and others, are showing no significant correlation. Willis’ dark blue contour is quite close to showing the limit of significant correlation.
Since Willis understands the arcane workings of R far better than I , perhaps he can clarify how the colour banding works. I’m guessing that anything blue here is between -0.9 and -1.0 , though it could be 0.75 to 0.85.
Hm, I don’t see want to be all negative, but do you have any explanation, or at least an idea/ hypothesis to what the cause of this increased reflection can be?
To me it seems like you have just shown the obvious fact that increased SW warms the surface which gives increased LW, and vice versa. Or am I missing something?
/Jan
Nick Stokes says:
January 8, 2014 at 1:56 pm
Nick, Phil claimed that clouds absorbed and scattered 100% of the light.
Phil. says:
January 8, 2014 at 10:42 am
Now, there is likely an idea somewhere kinda sorta near to what Phil said that is right.
But no, Nick, Phil’s idea is not “right” as you claim. It is called “wrong” when someone claims that clouds both absorb and scatter 100% of the light.
As to what idea similar to Phil’s might be right … what does that have to do with the topic of the thread, or with my comment on IR that Phil was ostensibly answering to … and why should I care?
w.
Matthew R Marler says:
January 8, 2014 at 2:27 pm
He is right about how Lw is measured, but that is meaningless. Whether it is measured directly or indirectly, so what?
He is wrong, however, about constraints. There is no constraint that there be a net TOA balance at any given instant at either the local or global level … and we are dealing with a string of instantaneous measurements.
w.
It seems that the red areas are being decorrelated by the influence of cooler waters being dragged in by the major ocean gyres , as I suggested earlier.
It may be worth checking this against a graph of mean SST but it seems there is a temperature limit below which this regulatory effect does not work. Since it’s all based on evaporation, clouds and storms that is probably consistent with Willis’ hypothesis.
If too much of the SST in a region is below that ‘trigger’ value, the feedback won’t happen.
Willis Eschenbach says: January 8, 2014 at 2:51 pm
“Yes, the LW is equal to SW + LW – SW. And yes, 4 is equal to 7 + 4 – 7 … again, what is your point? Does that make 4 the wrong answer?”
It makes it something you can’t usefully correlate with 7. “LW”=Tot-SW. Tot and SW are independently measured, with independent errors. You’re correlating “LW” with something (SW) that was used in the arithmetic from which it is derived.
If you correlate daily T_SFO with T_LAX, it will probably be positive. If it’s warm in SFO, it’s more likely than not to be warm in LAX. But if you correlate with T_LAX – T_SFO, that will likely be negative. T_LAX is partly correlated, but -T_SFO totally.
I’ve emphasised that TOT is subjected to a global energy constraint. But even if it weren’t, it’s the arithmetic link between “LW” and SW which makes correlation with SW unwise.
To me it seems like you have just shown the obvious fact that increased SW warms the surface which gives increased LW, and vice versa. Or am I missing something?
/Jan
In a word, yes. The correlation is _negative_ ie. increased SW produces LESS LW out , if you want to see the causation the way around. That means more the surface heats more it retains that heat. sounds like run-away warming tipping points to me.
However, if conditions which produce more LW out also produce a reduction in incoming SW, that causality would be a stabilising negative feedback.
So do we see run away warming in tropics when sun is overhead or do we see a fairly hard limit on max SST in tropics. Which interpretation fits the facts?
1sky1 says:
January 8, 2014 at 2:30 pm
Thanks, sky. It is true that something on the order of 80 W/m2 is absorbed by the atmosphere. It is also true that energy absorbed in the atmosphere cools the system compared to the same energy hitting the surface.
However, as my series of articles on volcanoes shows, the global temperature is remarkably insensitive to dust in the air. I hold that this is because as soon as the planet starts to cool, the tropical albedo drops, and thus more energy enters the system to restore the equilibrium.
We know that this is true from the correlation of albedo with temperature in the tropics, which is strongly positive—the warmer it gets, the higher the albedo gets from increased clouds, and vice-versa. So when the earth cools from e.g. airborne dust, we get less tropical clouds, and thus more sunlight to compensate for the loss.
So I fear to say, the “critical factor” as you call it is not the amount of sunlight intercepted by dust. The critical factor is that there is a thermoregulatory system in place which keeps the temperature from varying much, despite large variations in radiation due to things like the amount of atmospheric dust.
w.
Willis Eschenbach says: January 8, 2014 at 3:01 pm
“Nick, Phil claimed that clouds absorbed and scattered 100% of the light.”
No, he said:
“Each droplet in the cloud will absorb ~100% of the incident light and also scatter an equal amount of the incident light.”
and that’s true in the van de Hulst formula, large radius limit (not large wavelength, as I wrongly said).
As to why you should care, I don’t know. Greg cares. I’m just noting what the formula says.
Nick , in what way is SW + LW – SW correlated to SW ?
” I’m just noting what the formula says.”
the formula says 50%=50% not 100%+100% . What Phil said was confused and wrong. If he had said 50% absorbed and as much scattered, no one would have commented. It would have been correct but irrelevant.
I tried to point out his error in a light-hearted way but he didn’t get it. Too subtle I suppose. Can we drop that now?
Nick , in what way is SW + LW – SW necessarily correlated to SW ?
Jan Kjetil Andersen says:
January 8, 2014 at 2:56 pm
Jan, the SW in question is upwelling SW reflected from the clouds.
HTH,
w.
Alec Rawls: “But there is also a simpler explanation for this anti-correlation. Where clouds block incoming solar the planet below warms less, leading to less outgoing LW. ”
Same error as Jan it seems. Positive correlation.