Guest Post by Willis Eschenbach
It has been known for some time that the “Pacific Warm Pool”, the area just northeast of Australia, has a maximum temperature. It never gets much warmer than around 30 – 31°C. This has been borne out by the Argo floats. I discussed this in passing in “Jason and the Argo Notes“, and “Argo Notes Part 2“. I’d like to expand on this a bit. Let me be clear that I am by no means the originator of the claim that there is a thermostat regulating the maximum ocean temperature. See among many others the Central Equatorial Pacific Experiment. I am merely looking at the Argo data with this thermostat in mind.
First, Figure 1 shows the distribution of all of the ~ 700,000 surface temperature measurements taken by Argo floats to date.
Figure 1. A “histogram” shows how many data points fall in each of the 1°C intervals shown along the bottom axis. The maximum is in the interval 28°-29°C.
The number of temperature records peaks around 29°C, and drops quickly for temperatures above 30°C. This clearly establishes the existence of the mechanism limiting the oceanic temperatures.
What else can the Argo data tell us about this phenomenon? Quite a bit, as it turns out.
First, a look at the year by year evolution of the limit, and how it affects the temperatures at different latitudes.
Figure 2. Annual temperature variations measured by all northern hemisphere argo floats that exceeded 30°C. Temperature observations are colored by latitude. Click on image for full-sized graphic.
A couple points of interest. First, the cap clearly affects only the warm parts of the year. Close to the equator, that is most of the year. The further from the equator, the less of the annual cycle is affected.
Second, the majority of the breakthroughs through the ~30° ceiling that do occur are from areas further from the equator, and are short-lived. By and large, nobody exceeds the speed limit, especially those along the equator.
Figure 3 is a closeup of the years since 2005. I chose this starting point because prior to that the numbers are still changing due to limited coverage. To show how the mechanism is cropping the tops of the warmer parts of the year, I have added a Gaussian average (129 point width) in dark gray for each two-degree latitudinal band from 0°-2°N up to 10°-12°N.
Figure 3. Annual temperature variations measured by all northern hemisphere argo floats that exceeded 30°C. Dark lines have been added to highlight the average annual swings of the data by latitude band. Click on image for full-sized graphic.
As you can see, the warm parts of the yearly cycle have their high points cropped off flat, with the amount cropped increasing with increasing average temperatures.
Finally, here is the corresponding plot for the southern hemisphere:
Figure 4. Annual temperature variations measured by all southern hemisphere argo floats that exceeded 30°C. Click on image for full-sized graphic.
Note that there is less of the southern ocean that reaches 30°C, and it is restricted to areas closer to the equator.
Next, where are these areas that are affected by the temperature cap? I had always thought from the descriptions I’d read that the limitation on ocean temperature was only visible in the “Pacific Warm Pool” to the northeast of Australia. Figure 5 shows the areas which have at some point been over 30°C.
Figure 5. Locations in the ocean which are recorded at some time as having reached or exceeded 30°C.
Figure 5a. A commenter requested a Pacific-centered view of the data. We are nothing if not a full-service website.
Clearly this mechanism operates in a wider variety of oceans and seas than I had realized, not just in the Pacific Warm Pool.
Finally, here is another way to consider the effect of the temperature maximum. Here are the average annual temperature changes by latitude band. I have chosen to look at the northern hemisphere area from 160 to 180 East and from the Equator to 45°N (upper right of Figure 5, outlined in cyan), as it has areas that do and do not reach the ~ 30° maximum.
Figure 6. Average annual temperature swings by latitude band. Two years (the average year , shown twice) are shown for clarity.
Note that at say 40°N, we see the kind of peaked summer high temperatures that we would expect from a T^4 radiation loss plus a T^2 or more evaporative loss. It’s hard to get something warm, and when the heat is turned down it cools off fast. This is why the summer high temperature comes to a point, while the winter low is rounded.
But as the temperature starts to rise towards the ocean maximum, you can see how that sharp peak visible at 40°N starts first to round over, then to flatten out at the top. Curiously, the effect is visible even when the temperatures are well below the maximum ocean temperature.
Speculations on the mechanism
I want to highlight something very important that is often overlooked in discussions of this thermostatic mechanism. It is regulated by temperature, and not by forcing. It is insensitive to excess incoming radiation, whether from CO2 or from the sun. During the part of the year when the incoming radiation would be enough to increase the temperature over ~ 30°, the temperature simply stops rising at 30°. It is no longer a function of the forcing.
This is very important because of the oft-repeated AGW claim that surface temperature is a linear function of forcing, and that when forcing increases (say from CO2) the temperature also has to increase. The ocean proves that this is not true. There is a hard limit on ocean temperature that just doesn’t get exceeded no matter how much the sun shines.
As to the mechanism, to me that is a simple question of the crossing lines. As temperature rises, clouds and thunderstorms increase. This cuts down the incoming energy, as well as cooling the surface in a variety of ways. Next, this same process moves an increasing amount of excess energy polewards. In addition, as temperature rises, parasitic losses (latent and sensible energy transfers from the surface to the atmosphere) also go up.
So … as the amount of total radiation (solar + greenhouse) that is warming any location rises, more and more of the incoming solar radiation is reflected, there are more and more parasitic losses, more cold water and air move from aloft to the surface as cold wind and rain, and a greater and greater percentage of the incoming energy is simply exported out of the area. At some point, those curves have to cross. At some point, losses have to match gains.
When they do cross, all extra incoming energy above that point is simply transferred to the upper atmosphere and thence to the poles. About 30°C is where the curves cross, it is as hot as this particular natural system can get, given the physics of wind, water, and wave.
I make no overarching claims for this mechanism. It is just one more part of the many interlocking threshold-based thermostatic mechanisms that operate at all temporal and spatial scales, from minutes to millennia and kilometres to planet-wide. The mechanisms include things like the decadal oscillations (PDO, AMO, etc), the several-year Nino/Nina swings, the seasonally opposing effects of clouds (warming the winters and cooling the summers), and the hourly changes in clouds and thunderstorms.
All of these work together to maintain the earth within a fairly narrow temperature band, with a temperature drift on the order of ± 0.2% per century. It is the stability of the earth’s climate system which is impressive, not the slight rise over the last century. Until we understand the reasons for the amazing planetary temperature stability, we have no hope of understanding the slight variations in that stability.
My regards to you all,
w.
UPDATE (by Anthony):
Dr. Roger Pielke Sr. has some praise for this essay here:
Stephen Wilde says:
February 15, 2012 at 4:00 pm
//////////////////////////////////////////////////////
You need to clarify your statement a bit re: energy in the air. Are you talking about photons ‘in the air’? Are you talking about KE in the molecules? Are you talking about PE in the gravitational field? All of these are different ‘energies in the air’ and they all have differing impact on energy leaving the ocean, eh?
example… You can have warm air that does not impact the radiant energy leaving the ocean any differently than cold air does. You can have warm air that DOES impact the amount of energy leaving the ocean by conduction.
There are too many things going on to reduce the whole process to ‘you can’t have it both ways’.
You can, actually.
Chris Colose said:
“If the troposphere warms, then the SST threshold to kick in convection (and related cloud feedbacks) must also increase.”
In fact any extra energy in the troposphere will cause the tropopause to rise which makes convection higher and more effective as a heat dissipation process.
At a point determined by atmospheric pressure via the Gas Laws and the level of solar input the rise in the tropopause will offset the additional energy at the surface by increasing the rates of evaporation and condensation in the deeper/higher tropospheric column sufficiently to prevent any further surface warming but with a slight shift in the surface air pressure distribution instead.
That point would appear to be around 30C depending on local conditions
The low pressure region supplying energy to the ITCZ will deepen and the high pressure cells either side will intensify with the effect of widening the tropical air masses. The models do incorporate that process.
The problem then for AGW theory is that such changes from human CO2 emissions appear to be trivial compared to natural sun and ocean induced changes of a similar nature which gave us MWP, LIA and current warm period.
Stephen– I suppose I expected the reader to connect my statement concerning the adjustment to a moist adiabat to the stability field (not a great assumption on my part). That adjustment has been doubted by some (which relates to the whole ‘hotspot’ issue in the upper troposphere) but was one basis for the independent examination of this by the Johnson and Xie study, and they found that the adjustment is close to theory. To the extent this adjustment approximately holds in a warmer world, then the SST threshold will increase.
Paul Bahlin:
i) For the purposes of surface temperature one is considering kinetic energy.Only kinetic energy is recorded on sensors.Furthermore, evaporation converts kinetic energy to latent heat which does not record on sensors until released by condensation higher up where it is more readily lost to space.
ii) The oceans will radiate at the temperature of the ocean surface regardless of the air temperature above.
iii) If warm air above the ocean affects conduction from sea surface to air so as to warm the sea surface then evaporation will increase. The issue of humidity doesn’t count because we are considering the global average.
iv) “All of these are different ‘energies in the air’ and they all have differing impact on energy leaving the ocean, eh?”
They don’t because the rate at which solar shortwave stored in the ocean can leave the ocean is set by atmospheric pressure due to the fact that it is pressure which sets the energy cost for a given amount of evaporation. At 1 bar the energy cost is 5 units converted to latent heat for each 1 unit of energy input. That is why evaporation is a net cooling process.
It is necessary to completely separate solar energy which gets past the evaporative layer from longwave generated by the components of the Earth system which does not. There are two different sub systems for energy transfer to consider and they appear to operate independently.
One cannot have it both ways.
“To the extent this adjustment approximately holds in a warmer world, then the SST threshold will increase.”
Only if one increases solar input, atmospheric mass or the gravitational field.
Anything else only results in a redistribution of energy between surface and tropopause and between equator and poles.
During the late 20th century warming period more solar energy entered the oceans due to reduced global cloudiness so there might have been a slight increase. The test is what happens now that global cloudiness has increased assuming the increase lasts a similar period of time to the earlier decrease in cloudiness.
I don’t expect you to agree given your committment to the issue. We can but wait and watch how the natural world behaves now that we seem to be looking at more useful diagnostic parameters.
I think it helps to realise that temperature changes at the surface or changes in atmospheric energy content for whatever reason are linear increases..
However a rise in the height of the tropopause results in a geometric increase in the surface area of the tropopause around the globe which causes a geometric increase in the efficiency of the energy transfer processes between surface and tropopause.
Willis previously referred to curves intersecting which I think is a good way of looking at it.
With the efficiency of the energy transfer processes increasing geometrically it is very easy for small rises in the height of the tropopause to maintain a cap on temperatures that can only rise in a linear fashion.
Since we have had liquid oceans for 4 billion years and relatively constant global temperatures despite changes in global atmospheric density and changes in solar insolation since the time of the early faint sun the mechanism is clearly very reliable.
If human GHGs do add extra energy to the atmosphere (not really proved but never mind for the moment) then as against the system response to natural changes the system response to our puny input would be negligible.
Remember too that not long ago it was claimed by some that the more zonal and poleward jets of the latye 20th century were a result of human emissions and assumed to be permanent.
Since then, human CO2 emissions have continued to rise but the current indications are that the jets have moved back to a more meridional/equatorward track.
It is far more likely that the cause is natural solar and oceanic variability rather than the human influence.
Can you give figures as to how far our human emissions really did shift the surface pressure distribution and the permanent climate zones now that the trend seems to have reversed from natural causes ?
Willis is always demanding figures and sound maths. Where is it on that issue ?
Stephen Wilde says:
February 15, 2012 at 4:00 pm
Has anyone realised that if the extra energy in the air does reduce the flow of energy from ocean to air then the air would be no warmer because less would be coming out of the ocean ?
_____
Yes, I’ve noticed that, as well as several others. The thermal gradient across the skin layer is less steep, meaning of course, heat flux is reduced. That, along with more heat going into the oceans through downwelling, could be just some of the reasons ocean heat content continues to increase. Skeptics want to keep harping on the DWLWR not penetrating the skin layer, but I’m wondering why they don’t examine in detail how that same increased DWLWR might affect the thermal gradient of the skin layer itself. This is damn complicated stuff, as research articles like this:
http://journals.ametsoc.org/doi/pdf/10.1175/2009JPO3980.1
Well illustrates. The bottom line is, DWLWR doesn’t have to penetrate to the skin layer to effect the heat flux across that layer, or, indirectly then, how much warm water gets pumped back down into the deeper ocean through downwelling as less heat has been leaving as the thermal gradient across the skin layer is reduced from that same increase in DWLWR.
Willis and Nick
I revert on what I shall term the scientific issues arising out of Nick’s post of February 14, 2012 at 9:45 pm and Willis’s (jump on the bandwagon) post of. February 15, 2012 at 12:22 am
Nick’s post was extremely material and goes to the very heart of the matters raised by the GHE theory and what we know from measurements of the oceans. It is somewhat unfortunate that Willis although right to acknowledge the importance of Nick’s post did not seek to put it in perspective so that the further implications of Nick’s observation can be considered. These further implications are important. Contrary to Willis’s assertion “So richard doesn’t realize it…” I do realize the implications of the factual absorption characteristics of DWLWIR in water, and that is precisely why I am raising the issue and saying that there is a problem here that requires an answer. There may well be a good answer, but to date no one is putting it forward, and instead the issue has been side stepped.
I am somewhat pressed for time and I will write later on the ethics issue (which does not concern Nick) and I will only relatively briefly deal with the nub of the scientific issues. Before, I comment on the science, I will set out my basic position (since my character appears to be under some assassination)
My basic stance
1, I am sceptical of the majority of the issues raised by the GHE theory. That said, I fully accept the behavoir of CO2 in laboratory conditions, and fully accept that we measure a DWLWIR signal. I do however question precisely what that signal is and what, if any, sensible work, ‘energy’ in that signal can perform. I do not dispute the wavelength transmissions and/or absorptions of the various GHGs nor GHLs (Green House Liquids such as water).
2. Since I am sceptic, I am open to persuasion as to the correctness of any issue. I deny nothing, I just want to see what I consider to be satisfactory proof.
3. Like the majority of commentators on this blog site, my interest is to get to the truth. In view of that, if I have made a mistake in any thing that I have written, I am happy to put my hand up and accept the errors of my ways. Since I am not dogmatic, I have no problem in dropping a view that I may previously have held if satisfactory evidence is adduced showing the correctness of some contrary position. In view of the complexities of the issues raised, the lack of relevant quality data and experimentation and the many unknowns and not well understood processes, any views I express are only tentative. I fail to understand how there can be any firm views on the majority of the issues raised in this wide debate.
4. As far as I am concerned, the null hypothesis is that the ocean is in perfect equilibrium. On average figures, and in approximate terms, it receives 170 w/m² solar and loses 70 w/m² latent and 30 w/m² sensible and 70 w/m² radiation., I say perfect ‘equilibrium’ but I mean this loosely since in the Earth’s dynamic system there is never perfect equilibrium. Because I am sceptical, I am open to proof that that is not the appropriate stance.
5 I do not accept the relevance of any of the figures that I set out below (although I am open to persuasion that they are correct and are material) and use these as these are a ‘standard’ as used by those promoting the GHE theory.
6. I have no issue with the point that Nick raised in his post of. If we use his figure for DWLWIR, I fully accept the approximate calculation he performed, ie., that it would lead to approximately 4.6m of precipitation. I also appreciate the significance of that point but I consider that it confirms the thrust of the issue I was raising. I will explain below why I hold that view. I am open for Willis to prove that I am mistaken by now addressing the scientific issue which he has declined to address despite have been asked to do so on a number of occasions spanning a number of years. I am unsure whether he has an explanation, but no doubt he will let us know, or he will once again seek to side step the issue. Not intending any slur on Willis’s character, just as a matter of fact, I have lost count of the number of times that he has side stepped these issues (and/or similar issues raised by other commentators).
THE SCIENCE ISSUES RAISED (and the optical physics point).
7. Essentially, the GHE is a matter of optical physics and thermodynamics. The optical aspects are at the root. The claim being that the atmosphere is largely transparent to incoming solar but opaque to radiated LWIR which is therefore both absorbed and re- radiated (the latter when Earth bound I refer to as DWLWIR).
8. The optical aspects of the theory are entirely dependent upon the wavelength of the EMR and the absorption characteristics of the medium through which the EMR is travelling. It applies to both gases and to liquids. Some gases (and liquids) are transparent to certain predominant wavelengths, whereas they are opaque to other predominant wavelengths. We are particularly concerned with the gases and liquids that are opaque to LWIR and/or DWLWIR since these absorb radiation in that wavelength.
9 The theory is very dependent upon the absorption characteristics of GHGs and GHLs (Green House Liquids). In fact, it stands or falls by these characteristics.
10. Without dealing with albedo and the absorption of solar in the atmosphere, the GHE theory goes (using standard average figures) as far as the oceans are concerned: that there is on the incoming side of the energy budget, solar of 170 w/m² + DWLWIR of 320 w/m², and on the outgoing side, the oceans lose some 70 w/m² latent and 30 w/m² sensible and radiates 390 w/m². In that manner they are in radiative equilibrium. Fine as a matter of accounting.
11 .Those proposing the theory stress the absorptive characteristics of the various gases that make up the atmosphere. However much less fanfare is given to the absorption characteristics of water. Of course, the absorption characteristics of water are just as important as the equivalent characteristics of the various gases that make up the atmosphere. In fact. I would suggest that it is more important given the heat capacity of water, the mass of water on the planet, and the energy involved in the various phase changes of water and on our planet water is very dynamic and is constantly (somewhere) changing from one phase to another and back again. Earth is a water world, and water dominates the climate and its responses.
12. So turning to the optical physics point, it is important to examine the absorptive characteristics of water. How does it handle LWIR? This is important because those proposing the theory claim that it is (on average) constantly being bombarded with 320 w/m² of DWLWIR. That being the case, what happens to that 320 w/m² of DWLWIR and what work can it do?
13. The answer lies in the absorptive characteristics of water (and the sensible energy contained in DWLWIR). In my earlier post (February 14, 2012 at 9:19 pm), I attached the ‘accepted’ plot of those characteristics. Neither Nick nor Willis sought to challenge the correctness of that plot. Nor did Nick or Willis seek to dispute that 20% of all DWLWIR is fully absorbed by water within the first micron, Nor did Nick or Willis seek to dispute that 60% of all incoming DWLWIR is fully absorbed within the first 4 microns of water. I consider this to be uncontentious and this is factually the position as a matter of basic physics, ie, as a matter of basic optical physics. For convenience, I attach the plot again since it is central to the issue raised by Nick.(although I am not led to understand that there is any dispute as to what I have said on the absorptive characteristics of water).
14. So what is the implications of this factual absorption? I suggest that this all depends upon whether the DWLWIR signal measured is simply a signal incapable of sensible work, or whether it contains energy capable of doing sensible work (in the environs of Earth).
15. If DWLWIR is capable of sensible work, then as Nick correctly noted there is so much DWLWIR being fully absorbed by the oceans in their very top micron layers that it would ‘boil’ off so much of the ocean that there would be many metres of precipitation. As I say, I do not dispute Nick’s calculation. I accept that this is the prima facie implication of the absorption characteristics of water to DWLWIR.
16. This of course was the thrust of the point that I was making in my post of …There is an obvious problem arising out of the optical physics aspect, ie the absorption characteristics of water. Given that, as a matter of fact, 60% of all DWLWIR is fully absorbed within 4 microns, as Nick observes there is so much ‘energy’ inputted therein that it will ‘boil’ off metres of water. So why doesn’t it? I proffer my preliminary view in the post script.
17. I have been asking Willis for some years to address this problem and explain how DWLWIR can find its way down to the lower depths of the ocean given the absorption characteristics of DWLWIR and the fact that 60% of that is fully absorbed within the first 4 microns which would be evaporated (given the theoretical energy more than 4 microns would be evaporated). This is a fundamental problem striking at the heart as to how the GHE theory works over the oceans.
18. In short, what is the PHYSICAL PROCRSS involved that prevents this rapid evaporation (resulting from the absorption of the theoretical energy in DWLWIR) and which enables DWLWIR to be transmitted to depths below the depth at which it is fully absorbed? I do not consider that to be a ridiculous question. In fact, I consider this to be one of the very first questions that a student attending a climate science class would ask. The lecturer may have a good answer for the student but I do not consider that the lecturer would consider the question asked to be ridiculous.
I accept that Willis probably knows far more than I do about this and I am looking up to him as a lecturer and the elucidation he can bring to the table, Accordingly, I now look forward to Willis fully dealing with the optical physics issue and to explain how given the absorption characteristics of water this does not result in many metres of precipitation.
I look forward to Willis fully explaining the PHYSICAL PROCESS that stops the first micron of water being ‘boiled; off as a consequence of the ‘energy’ it fully absorbs form DWLWIR (ie., the full absorption of 20% of the total DWLWIR being directed at the ocean) and the PHYSICAL PROCESS thereafter which prevents each of the micron layers below from being ‘boiled’ off on a micron by micron layer basis at least down to the first 10 microns..
I look forward to Willis explaining the PHYSIVAL PROCESS involved whereby DWLWIR can penetrate beyond the depths that it is fully absorbed at and so penetrate before the deeper ocean before it has been ‘boiled; off and carried upwards by convection..
I do hope that Willis is not going to duck once more dealing with the problems that prima facie arise from the substantial absorption of all available DWLWIR in the first few microns of the oceans, by side stepping rather than addressing the issue head on.
PS. When I say that I have asked Willis to explain this issue before, I have not posed the question in identical form each and every time, merely the thrust of the issue to explain the physical processes involved that overcome the absorption problem which enables DWLWIR to heat the oceans.
The problem is more pronounced in the tropics since there is more DLWLIR being absorbed in the first 4 microns (since DWLWIR in the tropics is greater than the average). I haven’t checked the figures but I seem to recall Willis suggesting that it was between 400 to 500 w/m² which is in theory a lot of power.
For what it is worth, and I do not profess to be a sage, my preliminary view (and as I say, I am open to be persuaded otherwise) is that DWLWIR lacks sensible energy and that is why we are not seeing many metres of the oceans being boiled off.
For the absorptive characteristics of DWLWIR, see: http://scienceofdoom.files.wordpress.com/2010/10/dlr-absorption-ocean-matlab.png
richard verney says:
February 15, 2012 at 9:28 pm
And I look forward to your apology and retraction of your slimy remarks. If you expect anything before that happens, including another explanation of the PHYSIVAL PROCESS to add to the many I’ve given you already, you’re dumber than you act.
w.
Regarding richard verney says:
February 15, 2012 at 9:28 pm
———————-
Richard, I hope if Willis ever responds to this he will consider some logical assertions in regard to heating the oceans. First of all his own 30 C plus limitation of tropical heating of SST supports the supposition that ADDITIONAL LWIR from increased GHGs can do little to nothing to further heat the tropical oceans. Why? Because, as you point out, the increased energy is absorbed in increased evaporation/convetion from the very thin few mm, where it is all absorbed.
Two, how do we know what we are measureing coming from the oceans? Are we measuring the radiation from the atmosphere just above the oceans? Are we measuring the upwelling 390 W/m2 R coming from just the skin, with this being the result of all this down dwelling LWR? I truly do not know how the top ocean surface emission is separated from the very similarly emitting GHG filled atmosphere just above it.
Beyond this, is it not logical that any additional radiation in the tropics is used up in evaporation, conduction and transferr of latent heat high into the atmosphere? Is it also not logical that a similar increase of SWR would result in increased deeper level absorbtion of solar energy, as this energy is not absorbed at the surface and so does not as easily get used up in increased evaporation/conduction/radiation, but instead goes into deeper layers where any change can accumalate for day, weeks months or years, depending on the depth and location of the absorbtion of SWR increases or decreases ?
Does it not then logicaly follow that SWR increases or decreases have a greater affect on ocean T then LWIR increases or decreases. Why is the debate limited to deciding if LWIR has any affect on ocean T? It appears logical that the debate should be about the relative ocean heating abilties of an equal increase in SWR verses an equal increase in LWIR. And finallly, when considering that an ever higher percentage of the increased GHG LWIR results or is used up in evaporation /conduction and radiation, then if Lindzen and Spencer are correct, this results in greater negative feedback of increased clouds and reduced SWR.
R Gates says “Well illustrates. The bottom line is, DWLWR doesn’t have to penetrate to the skin layer to effect the heat flux across that layer, or, indirectly then, how much warm water gets pumped back down into the deeper ocean through downwelling as less heat has been leaving as the thermal gradient across the skin layer is reduced from that same increase in DWLWR.”
However,if the increase in DWLWR, especially in the tropics, results in increased evaporation, convection, conduction, and low level cloud formation, the their is reduced SWR heating the water below the surface, cooling it, and restoring or increasing the gradient. So, the summary could be, the intial GHG induced increase in DWLWR is used up, not in producing heat, but in the work required to increase the hydrologic cycle, which then results in negative feedback of increased clouds, which then reduce SWR heating the water below the surface, cooling it, and restoring or even increasing the gradient.
I’d like to see a proved relationship between the amount of DWLWIR that is used up in increased evaporation, radiation convection and conduction and the amount that is allegedly left over to warm the ocean after that process has been completed.
Given that 1 unit of energy input results in 5 units of energy being shifted to latent heat I cannot see how the evaporative process could fail to mop up anything left over from the other processes.
“The thermal gradient across the skin layer is less steep, meaning of course, heat flux is reduced”
That has not been demonstrated on a globally averaged basis. It is a mere assumption based on Fourier’s Law ( energy flow across a gradient will be related to the steepness of the gradient) but without taking into account the net cooling effect of the evaporative process.
Once evaporation is invoked as a means of drawing energy out of the ocean then Fouriers Law ceases to apply.The gradient itself is created and maintained by evaporation (amongst all other available processes).
Increased evaporation won’t increase the gradient either because when all the DWLWIR is used up the evaporative process stops increasing. Thus the effect of DWLWIR neither adds energy to the ocean nor slows down the background rate of energy flow from the ocean nor increases that flow.
The net effect on the ocean is zero. The effect is limited to the air and is miniscule compared to natural vraiability unless someone can demonstrate exactly how far the extra CO2 from human sources can shift the jetstreams.
As far as positive feedback from more humidity is concerned it appears that the data shows that there has been none. Apparently global humidity higher up declined slightly during the late 20th century warming period when AGW theory required it to have increased.
Willis
ELEVATOR SPEECH:-
1. The GHE theory works differently over land and over the oceans. This is due to the different characteristics between a solid and a liquid, and in particular the absorption characteristics of LWIR in water and the ability of water to evaporate and the processes involved in the phase changes of water.
2. It is claimed that DWLWIR must be absorbed by the oceans to prevent the oceans from freezing. This is because without the absorption of DWLWIR, the oceans would be losing substantial energy. In this regard, it is claimed that the oceans are losing some 390 w/m² by way of radiation, and some 70 w/m² latent and some 30 w/m² sensible, equating to a total heat loss of some 490 w/m². Against this heat loss, the oceans are only receiving by way of solar some 170 w/m². Accordingly, to stop the oceans from quickly losing energy and freezing, they must also be receiving some 320 w/m² DWLWIR. This must be absorbed by the oceans to maintain energy equilibrium.
3. Trenberth is well known for his theory that it is possible for the deep ocean to heat without there being any sign of heating in the upper ocean. Some are sceptical of the merits of that assertion. Those proposing the GHE theory would have one similarly believe that it is possible for DWLWIR to get into the deeper ocean without taking account of the manner in which DWLWIR is absorbed by water and the resultant energy that is absorbed as it penetrates.
4. It is accepted physics that 20% of LWIR entering water is absorbed within 1 micron. It is accepted physics that 40% of LWIR entering the ocean is absorbed within the next 3 microns such that within the first 4 microns 60% of LWIR entering the ocean has been absorbed. 60% of the claimed DWLWIR is l92 w/m² (in the tropics that figure would be more in the region of 270 w/m² or even possibly higher)
5. Thus in view of the absorption characteristics of water, the first 4 micron layer of the ocean absorbs and thereby contains not less than some 192 w/m² of energy. This energy cannot quickly migrate downwards because there is heat being transported from below such that conduction and convection current is operating in an upward plane. Ocean overturning cannot dissipate the heat absorbed in the first 4 micron layer at a rate quicker than it is being provided by DWLWIR which is an ongoing 24 hour a day replenishment process. In addition, the first 4 micron layer is also receiving solar energy. However due to the absorption characteristics of SWIR not very much solar is being absorbed in the first 4 micron layer. Solar is being absorbed at deeper depth and this absorption (ie, the absorption of solar at deeper depth) warms the ocean at deeper depths (say particularly 2 to 8 metres) and helps create the upward conduction and convection profile mentioned previously [which profile prevents the energy (from the absorbed DWLWIR) contained in the top 4 micron layer migrating downwards at any significant speed; the heat flux is up not down].
6. Further to 4 above, the amount of energy which is absorbed in the first 4 micron layer of the ocean from incoming DWLWIR is such that it would result in an evaporation rate of some 3 metres annually, if not more. This conflicts with assessed annual rainfall which is estimated to be about 1m.
7. It follows from 6 above that there is a problem with the amount of DWLWIR said to be received by the ocean. This problem would suggest that one or more of the following arises:
(i) DWLWIR does not exist as a real and tangible phenomena
(ii) There is a significant measurement error as to the amount of DWLWIR being received at the surface.
(iii) DWLWIR exists but is incapable of performing sensible work
(iv) The absorption characteristics of water are wrongly assessed.
(v) There is some presently not known and not understood physical mechanism which enables the about 192 m/w² absorbed by and contained in the first 4 micron layer to be transported downwards against the upward conduction and convection current which current is transporting heat from the ocean below (say from the first 3 to 5 metre layer of the ocean) at a rate faster than DWLWIR is supplying the ocean with DWLWIR.
8. Until an explanation can be put forward satisfactorily explaining the problem identified in 4 and 6 above and explaining why we are not observing precipitation in the order of 3 metres annually, which one would expect to see if DWLWIR has sensible energy and is of the magnitude claimed by those proposing the GHE theory and is being absorbed by the ocean in accordance with the accepted absorption profile of LWIR in water, the null hypothesis of the oceans being in energy balance in accordance with the budget set out in 9 below should stand
9. The ocean receives some 170 m/w² of solar energy and loses some 70 m/w² latent plus some 30 m/w² sensible plus some 70 m/w² radiation and is thereby in perfect equilibrium.
10. It may be no coincidence that those proposing the GHE theory strongly shout about the absorption characteristics of the GHGs to LWIR in the atmosphere but are rather quiet on the absorption characteristics of the watery oceans to LWIR.
“9. The ocean receives some 170 m/w² of solar energy and loses some 70 m/w² latent plus some 30 m/w² sensible plus some 70 m/w² radiation and is thereby in perfect equilibrium.”
Anything more that the oceans might lose would simply be part of a dynamic equilibrium between the oceans and the atmosphere whereby the amount lost to the atmosphere is matched by the amount received from the atmosphere.
The exchange with the atmosphere would mean that one does not need to propose some fantastical amount of precipitation. Evaporation simply mops up what is left over after all the other processes have done their work and on that basis the evaporation and precipitation quantities match well enough.
,
@Willis Eschenbach says:
February 15, 2012 at 12:59 pm
Paul Bahlin says:
February 15, 2012 at 11:08 am
I would like to know if it is even correct to say that down-welling radiation ‘heats the ocean’, or anything else for that matter. Here’s why…..
As far as I am concerned, Paul, that is a meaningless semantic quibble. However, to avoid it, I try to be very careful with my wording. For example, here’s how I worded it above:
And because part of the energy [lost by the ocean] is provided by the IR, this in turn meansthe ocean itself is losing less energy, and thus the entire mixed layer ends up warmer than it would be without the DLR.
Now, you want to say that the DLR does not “heat” anything … but the reality is that the ocean (and the planet for that matter) end up warmer when there is DLR than when there is not.
Since the planet ends up warmer, “heats the planet” makes perfect sense to me. But to you and others, somehow that’s unacceptable, so I use the wording above.
Either way you cut it … the world ends up warmer because of DLR, and to myself I call that “heating the planet” even though it may not be 100% scientifically accurate.
But to avoid this exact discussion, I didn’t say that the DLR heated the ocean, instead I said just what I said—that the ocean ends up warmer when there is DLR than when there is not, whether you call that “heating the ocean” or not.
//////////////////////////////////////////////////////////////////////////////////////////////////////////////
Willis
In response to the point raised by Paul you state: “As far as I am concerned, Paul, that is a meaningless semantic quibble”
With respect it is not a semantic quibble. The GHE is very clear: Unless 320 w/m² from DWLWIR is actually put into the ocean and effectively absorbed by it, the ocean is not in equilibrium balance.
Consider the classic equation. Ocean kicks out 70 (latent) + 30(sensible) + 390(radiation), totaling some 490 w/m² leaving the ocean. The ocean only receives 170 w/m² from solar, so unless the DWLWIR is actually effectively absorbed into the ocean, the ocean will quickly lose heat going into a death spiral and freeze.
It is therefore an integral part of the GHE theory to explain how the DWLWIR is effectively absorbed by the ocean and how it effectively heats the bulk ocean.
It would appear that there are particular problems with this in view of the accepted absorption characteristics of water to DWLWIR. Most of the DWLWIR gets absorbed in the first few microns inputting so much energy into that layer that it would give rise to copious evaporation and beyond the amount of annual rainfall that is observed. Both Nick and you pointed out how much evaporation results from the absorption of DWLWIR in the very top microns layer of the ocean.
I therefore hope that you can see that the point raised by Paul, is not a semantic quibble but one which strikes at one of the fundamental pillars upon which the GHE theory is based. This issue needs addressing rather than being brushed over, Of course, there may be a good answer as to the physical processes involved.
PS. In my elevator speech there are a couple of instances where I mis-typed w/m². any reference to m/w² should be read as a reference to w/m²
Willis writes “Reducing the size of the temperature gradient through the skin layer reduces the flux.”
Which is Minnett’s expected result. You want me to keep up? I’m not one of the people who say that the existance of GHGs dont make the ocean warmer. But I DO say that they dont *directly* warm the ocean. The dont warm the ocean in the sense that any of the back radiation enters the ocean.
Look at your quote. You’ve just said and believe the same thing!
Stephen Wilde says:
February 16, 2012 at 3:19 am
/////////////////////////////////////
Stephen
The classical approach does not result in any excessive amount of evaporation and as you say a balance between ocean and atmosphere can be struck equalizing and slight tempory imbalance (say1 to 3 w/m²).
In the classical approach, the evaporation is coming from the energy in the bulk ocean coming up from below. Say the first 8 to 15 metres of the ocean is at say 25 degC, it is the energy in this which is conducted upwards and when at the very top it evaporates. It would appear that it is not incoming solar exciting the top layer that evaporates. The absorption characteristics of water are such that very little solar is absorbed in the top microns. It therefore does not significantly play a role in energising the molecules in the top microns layer. Instead it penetrates deeper heating the deeper parts of the ocean.Of course, in the end, this is the source of the heat lying in the 8 to 15 metre range (and other depths as well) which is the driving force behind the upward energy flux which is supplying the heat to the top micron layer from below.
It is like a pot of water on a stove . It is the heat from below that drives the evaporation from the top.
DWLWIR on the other hand heats from the top down, but effectively only heats the first 10 microns with60% of the total ‘energy; from DWLWIR being absorbed in the first 4 microns. It is because of this absorptive characteristic that if DWLWIR has sensible energy, there is so much energy in the very top few microns that there would be copious amounts of evaporation leading to copious amounts of rainfall. This is the problem which appears to arise as a matter of otical physics. I have repeatedly invited various people to address this apparent problem and explain the phyical process where by DWLWIR can effectively heat the ocean rather than simply promoting evaporation and ending up not in the ocean but in the atmosphere above the ocean.
You know much more about air currents and jet streams. Much of what you say seems to make sense to me but I do not feel I know enough about jet streams etc to add much to the debate on that. An areas that I must delve into since it is very important and seems fascinating. I need some time, but then we all do.
Willis Eschenbach.
That’s a good thread.
To increase curiosity in this debate, I would add a thermostat recently discovered. This is the thermal behavior of trees and plants in general.
We found that a tree, (manguifera indicates. L.) alters the humidity of the air in their canopy increasing it or decreasing it, remaining neutral between 29 and 30 degrees celsius.
Maybe It’s explain the temperature control of our planet.
Richard:
A question for you….
Isn’t it true that outgoing long wave radiation from the ocean is a surface phenomenon, i.e. the outgoing photons are coming from the water molecules at the interface ONLY? They don’t come from a meter down, right?
If that is true then it isn’t necessary to hypothesize about the penetration of incoming long wave radiation. It too is a surface phenomena. I maintain that (at the surface) the incoming long wave photons, that don’t get reflected, get absorbed and re-radiated (at the surface), consequently resulting in a deduction from outgoing photons. They don’t ‘heat’ anything. They reduce long wave energy flux out from what it would be in the absence of down-welling long wave.
I would take issue with this distinction between heating and reducing cooling being reduced to a case of semantics because IMO the ‘semantics’ play nicely into a fundamental understanding of what is going on. This leads people to jump on the mechanism with statements about candles ‘heating’ forest fires. They’re essentially correct, at least in their semantic universe, but this does not mean that the candle can’t result in a hotter fire.
If you reduce cooling of an object while you pour energy into it, the temperature goes up but you haven’t ‘heated’ anything.
Willis Eschenbach.
That’s a good thread.
To increase curiosity in this debate, I would add a thermostat recently discovered. This is the thermal behavior of trees and plants in general.
We found that a tree, (manguifera indica. L.) alters the humidity of the air in their canopy increasing it or decreasing it, remaining neutral between 29 and 30 degrees celsius.
Maybe It’s explain the temperature control of our planet.
Stephen Wilde: February 16, 2012 at 12:25 am
says “….Given that 1 unit of energy input results in 5 units of energy being shifted to latent heat….”
This statement is still baffling me – are you saying the vaporized H2O is carrying away five times the energy that was required to vaporize it? I may be missing something here and was hoping someone more knowledgeable than I would comment, but….
Latent heat of evaporation is the energy used to change liquid to vapor. That amount required would seem to match that available (and released) upon condensation.
From http://www.usatoday.com/weather/wlatent.htm
• Latent heat of condensation (Lc): Refers to the heat gained by the air when water vapor changes into a liquid. Lc=2500 Joules per gram (J/g) of water.
• Latent heat of vaporization (Lv): Refers to the heat lost by the air when liquid water changes into vapor. This is also commonly known as the latent heat of evaporation. Lv= -2500 Joules per gram (J/g) of water.
Now, I know it takes about five times more energy to evaporate a quantity of water than it does to take that same quantity from 0 to 100 degrees C ……
Paul says
“If you reduce cooling of an object while you pour energy into it, the temperature goes up but you haven’t ‘heated’ anything.”
———
Of course true Paul. However, justlike with CO2 you must look at the feedbacks. In this case increased water vapor, which by it self, clear sky, reduces the radiation reaching the surface, and increased cloud cover, which one must then determine is that feedback positive or negative .The summary could be, the intial GHG induced increase in DWLWR is used up, not in producing heat, but in the work required to increase the hydrologic cycle, which then results in negative feedback of increased clouds, which then in conjuntion with increased W/V reducing SWR reaching the surface, further reduce SWR heating the water below the surface, cooling it, and restoring or even increasing the gradient.
“If you reduce cooling of an object while you pour energy into it, the temperature goes up but you haven’t ‘heated’ anything.”
The only portion of the ocean that sees a temperature rise from DWLWIR is molecules within the evaporative region that then evaporate earlier than they otherwise would have done and evaporation is a net cooling effect so no sensible temperature rise, merely more energy in latent form which is discharged to space earlier than it otherwise would have been.
Thus GHGs may slow down energy loss to space but the water cycle speeds it up again for a zero net effect.
“This statement is still baffling me – are you saying the vaporized H2O is carrying away five times the energy that was required to vaporize it? I may be missing something here and was hoping someone more knowledgeable than I would comment, but….”
Not quite. If it takes 1 extra unit of energy to cause a molecule of water to evaporate into a molecule of water vapour then the evaporative event then draws another 4 units of energy from the surrounding environment thereby removing 5 units to latent heat in all.
The thing is that since evaporation is constantly occurring even with no DWLWIR at all when humidity is less than 100% (nearly all the time) there are always lots of molecules that need just 1 more unit of energy to convert to vapour.
So any energy added brings forward the timing of the evaporative event for every molecule affected and the net outcome is cooling i.e. complete removal of all the DWLWIR.