Some Comments on the Lindzen and Choi (2009) Feedback Study
by Roy W. Spencer, Ph. D.
I keep getting requests to comment on the recent GRL paper by Lindzen and Choi (2009), who computed how satellite-measured net (solar + infrared) radiation in the tropics varied with surface temperature changes over the 15 year period of record of the Earth Radiation Budget Satellite (ERBS, 1985-1999).
The ERBS satellite carried the Earth Radiation Budget Experiment (ERBE) which provided our first decadal-time scale record of quasi-global changes in absorbed solar and emitted infrared energy. Such measurements are critical to our understanding of feedbacks in the climate system, and thus to any estimates of how the climate system responds to anthropogenic greenhouse gas emissions.
The authors showed that satellite-observed radiation loss by the Earth increased dramatically with warming, often in excess of 6 Watts per sq. meter per degree (6 W m-2 K-1). In stark contrast, all of the computerized climate models they examined did just the opposite, with the atmosphere trapping more radiation with warming rather than releasing more.
The implication of their results was clear: most if not all climate models that predict global warming are far too sensitive, and thus produce far too much warming and associated climate change in response to humanity’s carbon dioxide emissions.
A GOOD METHODOLOGY: FOCUS ON THE LARGEST TEMPERATURE CHANGES
One thing I liked about the authors’ analysis is that they examined only those time periods with the largest temperature changes – whether warming or cooling. There is a good reason why one can expect a more accurate estimate of feedback by just focusing on those large temperature changes, rather than blindly treating all time periods equally. The reason is that feedback is the radiation change RESULTING FROM a temperature change. If there is a radiation change, but no temperature change, then the radiation change obviously cannot be due to feedback. Instead, it would be from some internal variation in cloudiness not caused by feedback.
But it also turns out that a non-feedback radiation change causes a time-lagged temperature change which completely obscures the resulting feedback. In other words, it is not possible to measure the feedback in response to a radiatively induced temperature change that can not be accurately quantified (e.g., from chaotic cloud variations in the system). This is the subject of several of my previous blog postings, and is addressed in detail in our new JGR paper — now in review — entitled, “On the Diagnosis of Radiative Feedbacks in the Presence of Unknown Radiative Forcing”, by Spencer and Braswell).
WHAT DO THE AMIP CLIMATE MODEL RESULTS MEAN?
Now for my main concern. Lindzen and Choi examined the AMIP (Atmospheric Model Intercomparison Project) climate model runs, where the sea surface temperatures (SSTs) were specified, and the model atmosphere was then allowed to respond to the specified surface temperature changes. Energy is not conserved in such model experiments since any atmospheric radiative feedback which develops (e.g. a change in vapor or clouds) is not allowed to then feed-back upon the surface temperature, which is what happens in the real world.
Now, this seems like it might actually be a GOOD thing for estimating feedbacks, since (as just mentioned) most feedbacks are the atmospheric response to surface forcing, not the surface response to atmospheric forcing. But the results I have been getting from the fully coupled ocean-atmosphere (CMIP) model runs that the IPCC depends upon for their global warming predictions do NOT show what Lindzen and Choi found in the AMIP model runs. While the authors found decreases in radiation loss with short-term temperature increases, I find that the CMIP models exhibit an INCREASE in radiative loss with short term warming.
In fact, a radiation increase MUST exist for the climate system to be stable, at least in the long term. Even though some of the CMIP models produce a lot of global warming, all of them are still stable in this regard, with net increases in lost radiation with warming (NOTE: If analyzing the transient CMIP runs where CO2 is increased over long periods of time, one must first remove that radiative forcing in order to see the increase in radiative loss).
So, while I tend to agree with the Lindzen and Choi position that the real climate system is much less sensitive than the IPCC climate models suggest, it is not clear to me that their results actually demonstrate this.
ANOTHER VIEW OF THE ERBE DATA
Since I have been doing similar computations with the CERES satellite data, I decided to do my own analysis of the re-calibrated ERBE data that Lindzen and Choi analyzed. Unfortunately, the ERBE data are rather dicey to analyze because the ERBE satellite orbit repeatedly drifted in and out of the day-night (diurnal) cycle. As a result, the ERBE Team advises that one should only analyze 36-day intervals (or some multiple of 36 days) for data over the deep tropics, while 72-day averages are necessary for the full latitudinal extent of the satellite data (60N to 60S latitude).
Lindzen and Choi instead did some multi-month averaging in an apparent effort to get around this ‘aliasing’ problem, but my analysis suggests that the only way around the problem it is to do just what the ERBE Team recommends: deal with 36 day averages (or even multiples of that) for the tropics; 72 day averages for the 60N to 60S latitude band. So it is not clear to me whether the multi-month averaging actually removed the aliased signal from the satellite data. I tried multi-month averaging, too, but got very noisy results.
Next, since they were dealing with multi-month averages, Lindzen and Choi could use available monthly sea surface temperature datasets. But I needed 36-day averages. So, since we have daily tropospheric temperatures from the MSU/AMSU data, I used our (UAH) lower tropospheric temperatures (LT) instead of surface temperatures. Unfortunately, this further complicates any direct comparisons that might be made between my computations (shown below) and those of Lindzen and Choi.
Finally, rather than picking specific periods where the temperature changes were particularly large, like Lindzen and Choi did, I computed results from ALL time periods, but then sorted the results from the largest temperature changes to the smallest. This allows me to compute and plot cumulative average regression slopes from the largest to the smallest temperature changes, so we can see how the diagnosed feedbacks vary as we add more time intervals with progressively weaker temperature changes.
RESULTS
For the 20N-20S latitude band (same as that analyzed by Lindzen and Choi), and at 36-day averaging time, the following figure shows the diagnosed feedback parameters (linear regression slopes) tend to be in the range of 2 to 4 W m-2 K-1, which is considerably smaller than what Lindzen and Choi found, which were often greater than 6 W m-2 K-1. As mentioned above, the corresponding climate model computations they made had the opposite sign, but as I have pointed out, the CMIP models do not, and the real climate system cannot have a net negative feedback parameter and still be stable.
But since the Lindzen and Choi results were for changes on time scales longer than 36 days, next I computed similar statistics for 108-day averages. Once again we see feedback diagnoses in the range of 2 to 4 W m-2 K-1:
Finally, I extended the time averaging to 180 days (five 36-day periods), which is probably closest to the time averaging that Lindzen and Choi employed. But rather than getting closer to the higher feedback parameter values they found, the result is instead somewhat lower, around 2 W m-2 K-1.
In all of these figures, running (not independent) averages were computed, always separated by the next average by 36 days.
By way of comparison, the IPCC CMIP (coupled ocean-atmosphere) models show long-term feedbacks generally in the range of 1 to 2 W m-2 K-1. So, my ERBE results are not that different from the models. BUT..it should be remembered that: (1) the satellite results here (and those of Lindzen and Choi) are for just the tropics, while the model feedbacks are for global averages; and (2) it has not yet been demonstrated that short-term feedbacks in the real climate system (or in the models) are substantially the same as the long-term feedbacks.
WHAT DOES ALL THIS MEAN?
It is not clear to me just what the Lindzen and Choi results mean in the context of long-term feedbacks (and thus climate sensitivity). I’ve been sitting on the above analysis for weeks since (1) I am not completely comfortable with their averaging of the satellite data, (2) I get such different results for feedback parameters than they got; and (3) it is not clear whether their analysis of AMIP model output really does relate to feedbacks in those models, especially since my analysis (as yet unpublished) of the more realistic CMIP models gives very different results.
Of course, since the above analysis is not peer-reviewed and published, it might be worth no more than what you paid for it. But I predict that Lindzen and Choi will eventually be challenged by other researchers who will do their own analysis of the ERBE data, possibly like that I have outlined above, and then publish conclusions that are quite divergent from the authors’ conclusions.
In any event, I don’t think the question of exactly what feedbacks are exhibited by the ERBE satellite is anywhere close to being settled.
I’m not even sure that heat transfer in – heat transfer out is as closely allied to balance as is maintained. Heat, or thermal energy isn’t an independent absolute in the way that is characterised, and in any case, when it is converted into biomass, there is a tendency for it to have a negative efect on atmospheric warming.
it is a mystery what happens to heat. Some is radiated out, most leaves by convection. However: What of the theory of its disappearance as it thermalises? In a closed system, the introduction of cooling agents has this effect. The heat doesn’t migrate necessarily. The theory that heat reduces as electrons become less excited is a plausible one. Not the same as saying that thermal energy is a fixed quantity.
it is similar to the notion that during the operation of a fulcrum and a lever, we infer resistance and force, but when the lever returns to normal state, that force is no longer incurred. ie, it disappears.
As for climate sensitivity: The state of the oceans – as ghg’s as they’re called tend not to interfere with the cooling rate, as longwave radiation leaves at wavelengths too low for ghg’s.
The climate may be sensitive to solar radiation and ocean heat content – however, OHC is purely theoretical. there isn’t a strong argument that heat entering the oceans must automatically be stable and accumulate as it supposedly migrates like whales to other parts of the oceans to reappear at others. It is surely a percentage, of total solar heat…
Philogiston,
Sounds about like what I recall hearing/reading. Of course by the time one reaches a km down, one has no relevent visible light energy reaching there to heat up things and by the time one jumped in the water, their feet were a long long way below where IR can reach directly. For the far northern (or far southern) climes, one does have the case of turnover going on but this is not the area where one gets much solar energy power from.
Concerning your interesting question, the gravity potential energy should convert to some heat as one drops a chunk of water down deeper and and there is some also some energy from an increase in pressure as water is not perfectly incompressible. It is a fairly good insulator. FInally, one has geothermal energy coming in from below. While small compare to radiative values, the ocean is only dealing with conductive and convective modes of heat transfer.
P Wilson,
I was using the 4 deg C as the example – which is valid for fresh whater but like the freezing point, it is slightly different for salt water, which is denser than fresh as well so it adds complexity that may be very important in some situations but can obscure the basic concepts as well in understanding.
Concerning the life factor and energy conservation, there certainly is some effect as life absorbs energy and generally converts it to chemical storage of some sort – either that or uses it and it ultimately converts to heat. Life, even though it’s responsible for 21% oxygen in the atmosphere, is still a tiny fraction of energy balance in terms of absorption and generally, it’s not permanent on the moderate term, except perhaps for rock formation. A tree absorbs energy and makes wood. A fire will release that energy again. Decay will ultimately release the energy again. And on the long term, I bet even the rock – calcium carbonate built – up by life absorbing energy is going back into the subduction zones and will be cooked back into its original constituents giving back its energy.
cba (05:57:17)
different densities of ocean generally classed as thermohaline density gradients, although the common factors are temperature, density and salinity – what drives the THC with freshwater fluxes – as its name suggests, thermo-salt circulation. I don’t even know if we have an adequate picture of the oceans according to these characteristics.
cba:
(1) I don’t understand your whole point about the LW radiation not penetrating. Indeed, the skin layer plays the important role of reducing the transfer of the heat that is absorbed from the SW radiation back out into the atmosphere. See further discussion here: http://www.realclimate.org/index.php/archives/2006/09/why-greenhouse-gases-heat-the-ocean/
(2) You seem to be waving your hands around a lot talking about seasonal changes and what that has to say about the time constant for heating the oceans and then you go off on a big tangent about the relative radiation received by the two hemispheres and their climate, but it seems to me you are generating more “heat” than “light”. In particular, if you really believe that this shows anything significantly wrong with the time constants derived for long-term warming of the climate system, then you ought to be able to point to some definite issues, e.g., you could point to demonstrations that the climate models that forecast this timescale for response to the long-term warming aren’t able to correctly simulate the seasonal cycle or the relative temperatures of the two hemispheres. If that were the case, then we might really have something interesting to talk about, but to me your arguments now just seem like a lawyer bringing up all sorts of superfluous issues and questions in an attempt to distract the jury from the fact that his client was caught red-handed with the murder weapon.
cba: Just to give you an idea of why your argument about seasons doesn’t seem too convincing to me – If one looks at a graph of insolation vs latitude for, say, Dec 21, one sees that the variation is huge…Of course, areas north of the Arctic Circle get no insolation but even at 30deg north, the insolation is only about half of what it is for the whole Southern Hemisphere south of 30deg south. So, in fact, without considerable thermal inertia, temperature swings would be much more dramatic. Of course, the real earth is very complex, with lots of heat transport by advection, ocean currents, and other means, issues of cloud albedo and trapping of longwave radiation to consider, etc., etc. But, my point simply is that making a statement like, “The atmosphere will reach equilibrium in days to weeks, if not hours – proven by the existence of seasons with warm and cold weather” is really way too simplistic.
“”” Joel Shore (10:23:19) :
” But, my point simply is that making a statement like, “The atmosphere will reach equilibrium in days to weeks, if not hours – proven by the existence of seasons with warm and cold weather” is really way too simplistic. “””
Say Joel,
Why don’t you give me a shout, next time you obseve; or even hear about the atmosphere being in “equilibrium.”
That I gotta see !
“”” Bart (11:24:22) :
George E. Smith (23:08:51) : “Sorry; but I don’t agree…The system will only be unstable when the Nyquist condition says it is unstable…
That is the very definition of dominant positive feedback.
That condition can occur in “negative feedback” systems, because the propagation delays in ….
Then, the negative feedback has become ‘positive feedback’. Why? “””
Well I’ll let you use your definitions; mine have worked ok for me for over 50 years.
Negative feedback systems subtract from the input signal AT ZERO FREQUENCY; while Positive feedback system add to the input signal AT ZERO FREQUENCY.
Can’t say I’ve ever heard the term “Dominant Positive Feedback”; why wouldn’t one just call that an oscillator ? I’ve seen plenty of positive feedback systems that were not oscillators; qite stable at any operating frequency; and without the use of anything even approximating a negative feedback effect anywhere in the system.
My whole point has been that classical feedback analysis relies on the assumption that the forward gain and feedback blocks are unidirectional. I don’t have a single textbook in which there is any discussion of reverse transmission of the forward gain block or forward transmission of the feedback block, even though forward propagation through a passive feedback network is quite obvious.
When you try to model anything like a climate process as if it were a feedback system; yopu can’t find anything in the phuysical system that is even approximately unidirectional.
That doesn’t mean you can’t analyse systems with bidirectional propagation; they are just more complicated to analyse; so very few would bother to do it; rather than arrange system elements to conform to designs whose analysis is well uinderstood.
I don’t think the feedback model adds any understanding whatsoever to climate systems. Water vapor is a simple GHG just like CO2 except it has a much greater efect than CO2; and it is silly to believe that water vapor doesn’t start to act until jolted into action by CO2, in some supposed feedback process.
Phil. (05:34:50)
“You’ve described freshwater, saltwater has its maximum density at the freezing point.”
You’re right, I stand corrected. Seawater (35 p/th) does not have a density minimum at 4 C but actually subzero. But sea ice floats. So close to or at freezing there must be expansion. I looked up some references – there is in fact small adaiabatic warming of water when it descends to kilometer depths due to slight compression.
cba (05:57:17)
I looked up some references – there is in fact small adaiabatic warming of water when it descends to kilometer depths due to slight compression.
Joel Shore (10:23:19)
What do you mean by thermal inertia?
I agree that atmospheres and oceans never get anywhere close to equilibrium. The deep ocean currents can be considered as separate from surface currents and frequently the two flow in different directions. A round trip on oceanic circulation takes about 1000 years. This is why CO2 increase lags up to several centuries after climate temperature increase – slowly warming oceans hold less CO2 just as warm lager loses its fizz.
The non-equilibrium status leads to nonlinear-chaotic behaviour and the implications for feedback that have been discussed before.
I’ve noticed some engineers are joining in the debate. That brings back memories from University days – the engineers corridors in the prison-like halls of residence were always the most rowdy and noisy. Engineers always seemed aggressively self-confident. This is a good thing of course – who would want to step onto a bridge or plane designed by someone plagued by self-doubt?
Engineers make their own little worlds in what they design and need to have total understanding and control of all processes happening within those worlds. This is also a good thing. But taking this mind-set into climate study is problematic. There is more to climate feedbacks than what happens in a Fender Stratocaster and amp. The scale and complexity need to be more appreciated, including the role of chaotic non-linear dynamics that changes everything in terms of feedbacks and cycles/oscillations. Read some Tsonis.
“”” Phlogiston (14:55:18) :
Phil. (05:34:50)
“You’ve described freshwater, saltwater has its maximum density at the freezing point.”
You’re right, I stand corrected. Seawater (35 p/th) does not have a density minimum at 4 C but actually subzero. But sea ice floats. So close to or at freezing there must be expansion. I looked up some references – there is in fact small adaiabatic warming of water when it descends to kilometer depths due to slight compression. “””
The data I have says that salt water freezes at its point of maximum density for about 2.47% salinity. Sea water averages about 3.5% salinity, so seawater has a positive temperature coefficient of expansion always above its freezing point; and the problem with the freezing, is that the segregation coefficient ejects the salt on freezing so that the frozen sea ice is still pretty much fresh water (with inclusions of salt laden brines) In any case the isea ice is less dense that the surface waters, and the waters below have a positive coefficient of expansion; so there always is a positive convection density gradient in sea water; meaning that warmer waters want to rise, and colder waters sink.
Another problem is that at greater depths the sheer water pressure depresses the freezing temperature; so the water never freezes other than at the surface. The “lake turnover effect” is a phenomenon of fresh water lakes only; because of the 4 deg C temperature of maximum density OF FRESH WATER.
Engineers actually have to build stuff that works in a real world setting; so what may happen inside a computer simulation is of little use if it doesn’t properly model the real world.
For me it has been very beneficial to work as an engineer, as a Physicist, rather than an EE of ME or such; because I can always go back to the bare metal, and work with the physical fundamentals.
So I can start with a slab of Silicon (or Gallium Arsenide for that matter) and I can design the doping processes to create the various semiconducting layers; then I can design the active and passive circuit elements; and figure out how to build them out of the process layers; and then I can also do the detailed circuit design; specially in the analog world (digital circuit design is trivial ( at the circuit design level; not the logic design level)).
While I can and have done digital or mixed signal circuit design, I draw the line at programming any of that stuff. I never could come to grips with Smith’s first law of programming; “Before doing anything; it is always necessary to first do something else; no matter where you start.”
That is why Micro$oft Windows is the world’s largest computer virus; constructed of layer upon layer of bandaid’s du Jour.
I find too many people who write software never ever use it themselves.
Try taking some relatively ordinary process spec, and follow it to the letter; meaning; “Do what I tell you to do, when I tell you to do it; and do nothing at all (except continue to breathe) that I do not specifically tell you to do.”
In other words; assume nothing that you are not specifically told to do, is required to run the process.
Very few process specs following this rule, result in carrying out the process they were written for. In the end; operators make assumptions that they need to do things that are not specified. That’s great so long as you still have that operator; but try running the process; without that operator and see what happens to your product.
George E. Smith says:
I was quoting cba, so you might want to take this up with him. I have to admit that I have used the term “equilibrium” myself sometimes too and I know that it is a little sloppy. Better is “steady-state” (although one might argue about that too) or “in radiative balance”. At any rate, I think what is meant is usually clear from the context.
Phlogiston says:
Just that it takes a lot of energy to heat up the oceans because of their large total mass and specific heat. So, just like we say something with a lot of mass has lots of inertia because it takes a lot of energy to accelerate it to some speed, something that takes a lot of energy to heat up to some temperature has a lot of thermal inertia. People also sometimes use the term “thermal capacity”…and the top ~2.5 meters of the ocean have as much thermal capacity as the entire atmosphere!
One must deal in concepts other than pure textbook equilibrium. For instance a star is said to be in radiative equilibrium because it’s not collapsing or blowing up or even oscillating or fundamentally changing to any degree. Despite this, fusion is going on, hydrogen to helium (actual process is not important to this discussion), energy is flowing outward by radiative in some layers and by pure convection in other layers until it escapes into space. On the flip side, the material is attracted towards the center and it is a fluid which would/will collapse were it not for the injection of more energy inside. For a star like the Sun, this keeps up in a fairly stable fashion for several billion years. There is a temperature gradient starting around 16 million kelvins in the interior and by the time one reaches what we see every day, the photosphere, it’s down to around 6000 kelvins. It’s clearly not in thermal equilibrium yet it is in what is termed radiative equilibrium.
Joel shore, you say you’re a physicist (although some of your arguments have reminded me of the term ‘activist lawyer’ more so than the term ‘physicist’ at times as well). I am perplexed that you refer to some of my comments as handwaving when I’m attempting to convey things that a physicist should be able to grasp quite readily when laid out properly. I’m usually pretty good at laying things out in an understandable fashion and am concerned that perhaps I didn’t succeed in this effort.
The skin effect is simply the fact that the ‘skin’ has conducted/convected/evaporated/radiated off every bit of energy it can receive from below (and above) and that the temperature had to drop for energy to balance. It’s cooler condition also means that there is a greater delta temperature which results in an increase in conduction of heat to the layer.
The SW is going to penetrate, to a very limited amount below the region an amateur diver can go. Most will be absorbed much higher and only SW will penetrate down. It doesn’t take long before even the visible reds are missing. No IR is going anywhere and no IR / temperature effect on the ‘skin’ is going to have any measureable direct effect upon the incoming SW. The only significant effect is going to be more IR creating more evaporation creating more rising parcels of moist atmosphere that are likely to turn into clouds which will block massive amounts of incoming SW when present.
You’ve mentioned something about NH SH examples with Dec. 21 that didn’t make much sense as to what you’re driving at. Let’s put it more into a context and have you try it again. Peak solar occurs around June and minimum solar occurs around December. The difference from our orbital eccentricity is about 90 W/m^2 peak to peak and it looks rather much like a sine wave. Why don’t you ascertain the average solar incoming for NH and SH summers and try your arguments again. Despite NH summer time having an average power that is less than the SH’s average power incoming, the NH is slightly warmer in summer than the SH is in summer. The other factor is what is the fraction of NH land mass versus ocean surface and what is the fraction of SH land mass versus ocean surface? The answer should be telling about the effect of oceans and their storage versus continents with a particular lack of storage and convection.
phlogistan,
thanks for looking up the ref. it’s nice to get validated on theory sometimes.
Heh, Jailhouse Physicist.
==============
cba says:
Whatever. It would be helpful to know what your background is. I had earlier guessed you were in the atmospheric sciences but not climate science, although your description of stellar processes got me thinking astrophysics?
Well, what do you make of the experiment described in this RealClimate post: http://www.realclimate.org/index.php/archives/2006/09/why-greenhouse-gases-heat-the-ocean/ ? I am trying to understand your hypothesis. Here’s what it seems to be to me, correct me if I am wrong: There are large fluxes of SW and LW energy impinging on the surface. You seem to be positing that if the LW energy increases a little bit, then the result will (or may?) be very different than if the SW energy increases a little bit. I.e., the longwave increase will all go into evaporating moisture and producing more clouds and lowering albedo.
My question is what evidence you have to back up this hypothesis? Is there any support for it in the current literature? As far as I understand it, the general belief has been that the cloud feedback is mainly sensitive to the change in temperature, not the nature of the radiation that has increased.
Also, it is far from obvious that an increase in temperature would cause an increase in cloudiness since the atmosphere both warms (so the saturation vapor pressure increases) and moistens. In fact, the current climate models generally tend to predict an overall DECREASE in cloudiness as the climate warms, which causes both an increase in the escape of LW radiation from the atmosphere into space and an increase in SW radiation to the surface. In fact, although it varies from model-to-model, this tends to occur to a degree that by 2100 that there is very little net change in LW radiation and most of the change in radiative heat balance is provided by a change in SW radiation ( http://www.cgd.ucar.edu/cas/Trenberth/2009GL037527.pdf ) Of course, there is a fair bit of uncertainty in this due to the uncertainty in the cloud parametrizations.
I agree…I think it tells us that the oceans have a large thermal inertia.
It depends on where LW impinges on the oceans – at what wavelength/temperature. In order to ascertain what effect it had on oceans, it would have to be against the background/comparison of solar heating on oceans, ie, negligible. The first, or most potent effect from LW would be via water vapour which has enough peaks and shoulders to have a tiny effect. C02 would obviously add a tinier amount of surface to very cold parts of ocean surface. Generally, the wavelengths of ghg’s escape the longwave radiation at the surface – particularly c02. The claims of the RC are quite farfetched, and argue in reverse to some degree. I’m not sure that oceans even have a skin. Or has one been invented to justify the argument?
In 2009 (July) NOAA said ocean surface heated a lot, and the air heated a little. How can the air be heating the oceans when the ocean surface heats more than the air? its something of an impossibility.
The AGW consensus are moving the argument to oceans, hitherto overlooked, as the air temps failed to materialise, although that is going to be even more difficult to justify, and bring forth greater contradictions.
How can an increase in global warming lead to a decrease in cloud cover? Surely it would lead to an increase in cloud cover and increased precipitation at some point, which in turn initiate autonomous cooling events? At least, that’s what we’ve been experiencing for our several decades of “global warming”.
I’m not sure about others, who are labelled as sceptics, think about climatology as it is, though what should be clear is that climatologists don’t have much grasp of the present climate to be making predictions about future climates.
That Realclimate ocean skin theory is a bit of a hobby horse of mine because I see it as the only hope that the AGW theory has of overcoming the problem of getting air to warm oceans.
Given that the oceans control air temperatures they really do have to demonstrate warming oceans in order to maintain any credibility.
In effect the Realclimate theory relies on Fourier’s Law but ignores the much more powerful contrary effect of increased evaporation.
I have done my best to analyse the issues here:
http://climaterealists.com/index.php?id=4245
and if I have made any serious error I would like to know.
P Wilson (13:08:22)
Warmer air holds more water vapour so the initial reaction of the air from a warming influence from the oceans is for low level cloud to evaporate.
That leads to more insolation and that warming effect is added to the warmth emanating from the oceans so that increased convection soon ensues with increased cloud at all levels plus less insolation and cooling wind and rain.
It’s just like a morning with low cloud in unstable air which burns off by mid morning then after a clear period cumulus and cumulonimbus grow to give showers.
The energy released during an oceanic warming period is however long lasting and leads to an expansion of the equatorial air masses and a shift of all the air circulation systems poleward. The movement latitudinally of the ITCZ is a good proxy for whatever is going on whether it be global warming or cooling.
“The thing is that greenhouse gases absorb incoming solar energy at several wavelengths of the solar spectrum but only radiate it out again in the infrared.
Consequently increased greenhouse gases intercept some of the solar energy that would otherwise reach the ocean surface and penetrate it to add to ocean energy content.”
Water vapour absorbs some incoming solar radiation where it coincides with its wavelengths, and c02 absorbs some IR at 2.7 and 4. It is the LW that is seen as important for ghg’s – 4-10 and 13-70 microns for water vapour, although water vapour spans the whole range from 0.9 microns to 70 microns in the wavelength.
For the purposes of Atospheric temps however, it is the longwave that climatology thinks is the important factor
above addressed to Stephen Wilde
joel shore,
Rutherford is attributed with having said something like ‘physics is science. all else is stamp collecting’. I suppose you could say I do a bit of science and a bit of stamp collecting. I find that tending to categorize others is usually an indication of an attempt to change the issue or attack the opponent.
BTW, you’ve got albedo backwards. Cloud presence increases albedo and reduces total incoming power, especially the power capable of being deposited deeper in the ocean. Also, even incoming solar has a greater fraction below the visible than in the visible range.
Looking at the experiment, the first thought that came to mind was the not too relevent thought that mathematicians should leave physics to physicists. It was hard to follow and made little sense. And, it doesn’t prove what the author claims.
As an example, radiation is emitted from everything that above absolute 0. In a box of uniform temperature containing an object of same temperature, that radiation is balanced between that emitted by the object and that absorbed by the object. Consequently, nothing is changing concerning heat flow.
The author does determine that the ‘skin’ drops in temperature relative to the 5cm interior as the atmosphere radiates back less. What he fails to present (or perhaps fails to realize) is that as long as there is a difference in temperature between the ‘skin’ and the 5 cm point is that the heat flow from the interior is lower than what the ‘skin’ will radiate/convect/evaporate away. Rather he presumes that the emission will be less if the temperature gradient decreases. It doesn’t work that way. If there were no ‘skin’ effect, the temperature would be higher in the skin and it would radiate at a higher rate and the limitation would be with the surface. Also, the author only considers radiation.
His cloud cover is going to increase LW a bit but it’s going to decrease SW substantially. There’s going to be less heat entering the ocean at depth so less that needs to escape to maintain a balance.
Being the author has some nice fancy equipment and one would expect him to be able to correctly use it, I won’t comment on his measured results. There is though plenty of opportunity for plenty of problems.
Of course his co2 doubling delta forcing is the typical over estimate based upon clear sky tropopause altitude. In reality, it’s closer to 3.5 or 3.6 W/m^2 than to 4.0 and it’s not that meaningful since as you go higher – say to 70km, you find the co2 doubling effect for radiative transfer is closer to 2.6 W/m^2 (assuming fixed temperatures).
Concerning your interpretation of my statements, it’s fairly close. The increase in IR cannot heatup the ocean lower than the surface. It can though heat up the surface as well as evaporate more moisture. The experiment shows that in the data, using his results, the surface was never heated up beyond the 5cm layer. That means no actual heating is occuring from the surface. All one can claim from it is that the flow rate is reduced due to back radiation – but again, because the temperature is not at or above the 5cm below the surface point, the limitation in outgoing power (of all types) is due to the heat flow limitation below.
What claims do you feel need verification or validation? Generally, the scientific method simply requires a hypothesis to be falsified given one solid case of the data refuting it. Considering the state of cloud cover understanding including formation, it’s a bit premature to claim much of anything beyond the way basic physics works.
BTW, you’ll note that the experimental relationship established by that author shows 0.002 K/W/m^2. If the relationship were correct, it’d result in a whopping increase of 0.016 k rise for TWO doublings of CO2. That will result in a radiative increase of 0.09 W/m^2 despite the reception of an additional 8 W/m^2. This 8 W/m^2 is far IR and it isn’t going down into the ocean as radiation and 2nd law says it isn’t going down period. It’s also not radiating away so what do you think that leaves for the ‘disposal’ of this extra power?
while the general concensus of cloud formation is probably temperature, the nature of the radiation concerned may have an effect upon that temperature. Really short uV doesnt make it down through the atmosphere. IR doesn’t penetrate the ocean. Longer uV can ionize as can cosmic rays. Ion trails abound and there is a relationship (original wilson cloud chamber experiment was about cloud formation).
The bit of uncertainty in your cloud formation is more like the ten ton King Kong being called a little monkey. Cloud variation of albedo over the last 30 years is about 10 times greater than the dynamic range of the ipcc’s little uncertainties bar chart for all the forcings. Evidently, the other forcings and uncertainties are so small relative to this that they decided just to truncate it at something that fits within the chart in order for the other forcings to be seen.
you seem to confuse the simple notions of large inertia and large effect. Let’s try a simple electrical analogy. Let’s say you have a 12V power pack composed of D-cells in parallel with a 100AH 12V car battery feeding a 10 Amp headlight. Now let’s add one more item, a 10 k ohm resistor is connecting the car battery to the rest of the circuit. By itself, the D-cells could run this light for perhaps an hour to two hours and with a good connection, the car battery could run it for perhaps ten more hours. How substantial is this car battery reservoir going to be and how long will it keep the light lit? Just to provide the answer here, the car battery won’t discharge for quite a few days but its effect upon light will be so small as not even heat it up to a dull glow.
The moral of the example is that it’s not the size of the reservoir but the flowrate in and out of the reservoir that counts towards its contribution to the rest of the system. Applied to an ocean and climate, it means that the longer the time constant, the less the impact will be while it approaches some sort of equilibrium or constant state.
The fact that the NH has greater land surface and less ocean surface than the SH and achieves a warmer temperature in summer despite a significant increase in solar incoming radiation on average for the SH summer indicates there’s a difference between ocean and land effects. However, the fact that both have seasons that are somewhat comparable means there is not some massive difference brought on by mostly ocean. What’s more, precession does occur and eventually, over several thousand years, the aphelion and perihelion dates are going to swap around such that the NH gets the max during its summer and the SH gets the minimum during its summer. Since this has happened many times in the past and the Earth didn’t burn up totally you can also kiss your notion of high sensitivities goodbye and the proof of that is staring at you in the bathroom mirror early every morning.
wow, it took a while to finally get that response done.
p wilson,
actually the skin as mentioned above proves the opposite – that the limitations is the heat flow below – requiring the heat drop for energy to balance. LOL.
I like their stuff about increased h2o vapor causing a reduction inclouds. Didn’t you know? cloud cover is formed because of low moisture content LOL. I guess if they are going to violate the 2nd law of thermodynamics, they might as well trash the water vapor cycle as well. Obviously, warmer air with lower average molecular weight (making it less dense) doesn’t rise unless it is inside a hot air balloon. As it travels up the h2o vapor gets special dispensation from momma nature so that it doesn’t have to have an increase in relative humidity as the temperature drops nor does it become a candidate for cloud formation once it rises sufficiently high to be supersaturated. It’s all about special priveledges.
cba says:
These claims about violating the 2nd Law of Thermodynamics get rather tiresome. Where are you proposing the conventional theories violate this law?
As for the water vapor cycle, the point is that both temperature and water vapor are increasing as the climate system warms. In fact, both models and observations suggest that they seem to do so in a way that keeps the relative humidity on average roughly constant (although it does increase in some places and decrease in others). Hence, it is not at all obvious in which direction cloudiness will go.
And, if you want to argue that reduced cloudiness with warming is unphysical, then you would also have to take this up with Richard Lindzen, since it is the basis of his “iris hypothesis” ( http://en.wikipedia.org/wiki/Iris_hypothesis ) that warming would lead to a reduction of cirrus clouds (which reduce outgoing LW radiation more than incoming SW radiation) and that this would thus increase the amount of heat escaping to space, providing a negative feedback.
Joel Shore (19:17:25):
“As for the water vapor cycle, the point is that both temperature and water vapor are increasing as the climate system warms.“
Yo, Joel, what color is the sky on your planet?
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You bring to mind the movie: “Say Anything.”