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:
Roger @12:00pm
Roger @12:17
Roger @1:05
He never said it “didn’t go over” that temp. he said and I quote:
“It never gets much warmer than around 30 – 31°” The graphs even show many outliers above that point. Really man, pay attention and stop trying to change the subject. The subject being: a possible high limit to oceanic temps and the reasons for that possibility.
R. Gates says:
February 12, 2012 at 9:32 am
The oceans have a mass of 1.4E24 grams while the CO2 in the atmosphere has a mass of 3.16E18 grams. Dividing one by the other gives a ratio of 2.3E-6 (0.0000023). This shows the mass of the oceans is about 443,000 TIMES that of atmospheric CO2!
And now, R., you can see why Will has not said “anything about the inpact of increasing amounts of CO2 to the ocean as a whole” as you request.
Time to dispense with this CO2 kick of yours, R. Time to dispense!
(Or continue and I’ll be the only sucker pulled in by your attempted thread pirating.)
Sorry…meant to type “WIllis” rather than “Will”. I apologize, Willis. (Great post, by the way–must have the CAGW crowd worried by the looks of some of their responses.)
Water with excess charge shows spontaneous increase in surface area below −9.5 kV, stretching into threads and dividing spontaneously in smaller droplets. Droplet spontaneous deformation or subdivision is aided by surrounding electric fields and its dependence with the field may be assessed by plotting the apparent surface tension measured under a given voltage but decreasing distance to a grounded object, as shown in Figure 4.
Spontaneous water surface area increase is opposed to the usual minimum area ex- pected under gravity…
http://www.electrostatics.org/images/I1.pdf
30C is the average convection temperature for saturated parcels in uncapped atmosphere at sea level?
Interesting. Can you centre your world maps opposite Greenwich so that the Pacific isn’t split? That still seems to be where the most interest is.
Willis said:
“I’m just going to point out that you are a fool following the lead of greater fools, so you’ll find the atmosphere at Tallbloke’s much more congenial.”
I am following the lead of the Gas Laws which have been settled science for more than 300 years but which you have shown yourself determined to ignore.
A number of contributors here have pointed out to you that it is atmospheric pressure that determines the rate of energy flow from ocean to air and which puts a lid on the achievable temperature of the sea surfaces at current levels of solar input.
You, sir, are the fool here.
Second Law Violation insight into atmosphere motions
Different gases have different lapses (-g/Cp)
Closed, well insulated tall pipe loop of H2, heat exchangers top and bottom
Gives perpetual motion — Propeller inside, generate power
See — ” Modified Feynman Ratchet With
Velocity-dependent Fluctuations And The Second Law Of Thermodynamics”
To what extent is random broken, creating circulation patterns,
Even in an isolated System ?
I think its wrong to conclude that 30 to 32 degrees is a cap/limit for the oceans temperature based on the Argo data. All you could conclude is that the average environmental temperature in the warm zones is about 30 degrees C, which seems about right from Darwin to Singapore in my experience. If you were to increase the solar input I suspect it might raise ocean temps to a new slightly higher average.
Exactly where I am coming from as well. I would be utterly flabbergasted if any climate model used to predict catastrophic warming via amplification from positive feedback from water vapor included any SST limit at all. If such had been included then I just think that by now we would be discussing the difference between some modeled limit and the stark reality that Willis has brought to our attention.
The alarmists don’t just ‘hide declines’, they’re going to hide anything that threatens their agenda and this revelation certainly qualifies as such a threat. What other explanation is there for their rabid refusals of FOIA requests? (And if they already know or suspect such an SST limit exists perhaps we’ll learn of their intent to keep it hidden when the rest of emails are released?)
There are also some data points in figure 2 above 35C. Surely that would indicate that the ocean max temp cap was broken or the floats sensors were broken? You would have to be able to properly explain those data points to not falsify the max temp theory.
PROJECTION WHETHER TEMPERATURES PREDICTED BY THE OCEAN THERMOSTAT HYPOTHESIS REMAIN STABLE AS CO2 INCREASES NOW IN DOUBT,
The hypothesis of a Ocean thermostat does not guarantee anything. Singling out just another hypothesis and resting all insurance as prevention of global warming into the future is not as sound as first thought.
GENUINE SKEPTICS remain such. Holding up a theory and using it as our “bed pillow” to sleep soundly at night is lazy science. Not only that – it falls into the same trap as “blinders” science syndrome – by focusing on one theory to exclusion of all else.
The same applies to other resting pillows. The low sensitivity hypothesis. That one is yet to be proven false. However Roy Spencer believes with yet another ten years of data the hypothesis of low sensitivity will either be further strengthened or substantially weakened to irrelevance.
Read on……………..
http://classic.the-scientist.com/blog/display/54291/
The theory of ocean thermostats is a controversial one, says lead author Joan Kleypas from the National Center for Atmospheric Research in Boulder, CO. The theory goes that in the open ocean, increases in surface water temperature lead to more evaporation. The process of evaporation itself cools the water, but the cloud cover that develops also acts as shade, blocking further heating. But this feedback doesn’t function everywhere. “You’ll have evaporation over a swimming pool,” explained Kleypas, “But you’re not going to get cloud formation above it.”
The authors examined satellite data of surface temperatures from the years 1950-2006 and found a region of particularly warm waters in the western Pacific with temperature increases at half the rate of other areas. They compared the satellite data to a model predicting how surface temperatures, carbon dioxide levels, solar variability and other factors interact.
Even as other factors changed, the model predicted the same stable temperatures they’d observed in the data, suggesting a mechanism such as the ocean thermostat was at play, Kleypas explained. Comparison with a global dataset of coral bleaching showed that fewer bleaching events had occurred in that ocean region, suggesting that waters that were warmer but more stable might protect against coral bleaching.
It’s not perfect protection, says Kleypas. Big shifts in temperature, caused by monsoons, for example, could override the thermostat regulation, and corals in this region are actually more vulnerable because they can tolerate a smaller range of temperature shifts. Most corals commonly bleach after water temperature change by 1-2 degrees Celsius. In these corals, bleaching events were observed after a change of 0.2-0.3 degrees.
The researchers then projected whether the temperatures predicted by the thermostat hypothesis would remain stable as carbon dioxide levels increase. Now for the bad news: They won’t, said Kleypas.
Read more: Ocean thermostat protects corals? – The Scientist – Magazine of the Life Sciences http://www.the-scientist.com/blog/display/54291/#ixzz1mDRs5QaI
I note that there are some data points at temperatures > 30, but wonder if they all come from the same buoys. Is it possible that most of the buoys are only calibrated to a maximum of 30°C?
TGSG says at February 12, 2012 at 3:10 pm
“He never said it “didn’t go over” that temp. he said and I quote:
“It never gets much warmer than around 30 – 31°” The graphs even show many outliers above that point. Really man, pay attention and stop trying to change the subject. The subject being: a possible high limit to oceanic temps and the reasons for that possibility.”
My reply is directed at TGSG, G. Karst, and Richard Sharpe from above: Please refer to the following quote of the post:
“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.” (bolding mine)
“There is a hard limit on ocean temperature that just doesn’t get exceeded no matter how much the sun shines.”
My point is that there is no hard limit on ocean temperature, and that limit is certainly not 30 degrees C. Direct, impartial evidence was supplied to back up my assertion. It is up to you whether to believe the data or not. NOAA’s own data buoys in not-so-hot open ocean shows 34 degrees C. A peer-reviewed paper in the journal Oceanography states that wind is the key factor in limiting high open temperature.
But, this post has pretty pictures so if you want to go with that, by all means have at it. Don’t let me stop you.
Stephen Wilde says:
February 12, 2012 at 4:13 pm
I’m still trying to position your statement against the fact that oxygen (O2) wasn’t discovered until 1773 (or 1774 depending on who gets credit), which was only 238 years ago.
And your Gas Laws have been “settled science” for more than 300 years? Hmmmmmm…..
As a complete layman I hesitate to add to the professional’s comments here. As a long term resident of the east coast of Australia, a traveller, a sailor and consequently a weather watcher I have observed how the summer prevailing nor-easters keep areas in the south like Sydney cool but humid. In the north coastal Queensland is likewise kept somewhat warmer but still tolerable by the south east trades. In the far west of Queensland in the summer colourful cumulus clouds roll up, more often than not resulting in dry storms sometime starting bush fires by lightening strikes. I find it fantastic to see Willis’s analyses of our great oceans. It seems pretty obvious to a layman that as 70% of the earths surface is covered by substantial layer of water, how it responds to the energy from the sun is rather more meaningful than land energy measurements. One doesn’t find too many temp. recordings being obtained from underground mines or caves. Its always around 16*C I understand. Cheers from soggy Sydney.
sort of O/T cos i can’t open TipsnNotes:
15 Dec 2011: Australian: AAP: Bill Gates gives tick to carbon tax
Mr Gates, the founder of Microsoft who’s holidaying in Sydney with his family, said someone had to lead on tough global issues and it had to be hoped that by setting a good example, others would follow.
“I wish the world at large found it easier to get together on this because a carbon tax is a very important tool to encourage the invention of low-cost energy technologies that don’t emit carbon,” he told ABC Television.
“To help that happen, a carbon tax really is a key piece.”…
http://www.theaustralian.com.au/news/breaking-news/bill-gates-gives-tick-to-carbon-tax/story-fn3dxity-1226223361332
1 Feb 2012: Deutsche Presse-Agentur: Sydney sploshes through a cold, wet summer
Microsoft founder Bill Gates and other A-listers were in jumpers and raincoats rather than shorts and beach shoes during their Christmas holidays in Sydney…
The Weather Channel said Wednesday that Australia’s biggest city had its coldest December in more than half a century and its coldest and wettest January in over a decade…
The Gates family got fed up with Sydney’s weather and, like many of the locals, flew up to Queensland for a bit of southern hemisphere summer comfort.
http://news.monstersandcritics.com/asiapacific/news/article_1688430.php/Sydney-sploshes-through-a-cold-wet-summer
The ocean is a swamp cooler.
It is all in the BTUs.
Darn clever those Brits.
Oh, and nitrogen wasn’t discovered until approximately 1772. Indeed, this quote is instructive:
“Gases were poorly understood by chemists until the late 1700s. What is air “made of?” That question is difficult to answer for a number of reasons. ”
http://www.chemistryexplained.com/elements/L-P/Nitrogen.html
That “poor understanding” would be, oh, about 210 to 240 years ago. Yet Gas Laws have been “settled science for more than 300 years”?
What gasses are you referring to, Stephen WIlde?
Tim,
If you’re still reading, let me add a little more to my earlier explanation [at the risk of provoking the wrath of Willis]. The absorption and penetration depths of IR radiation into the ocean is not contentious [I refer to IR radiation similar to that of S-B black-body radiation at temperatures similar to the Earth, as experienced by the ocean surface].
Willis mis-characterizes the argument as saying that IR does not heat the ocean, which is not correct. It does, but the simple fact that sea surface temperature are lower than land surfaces refutes his rather simplistic counter arguments, and he also falls into the trap of talking about radiative flux but forgetting the word “NET”. His [self-edited] reply refers back to an earlier piece on WUWT where Dave Springer gave an excellent series of replies to discussions about this, but Willis’ replies repeatedly demonstrate that he missed the point. Many others also find it easy to conceptualize ocean stratification or mixing when it is described in terms of kilometres, metres and millimetres, yet cannot do so when the concept is further extended down to nanometres. i have done so myself.
I think Dave Springer is probably on-the-money, [even if he has made himself unpopular here by espousing a point that I can’t find mentioned on real climate]. Or, at least, I think Springer and others may have hit the nail on the head, if the IPCC models really do assume that there is no difference between the top nanometres and the top millimetre of the ocean. Evaporation of water does not occur from a millimetre below the surface, where diffusion [viscosity] has become less than dominant. The argument, as far as I am concerned, is a quantitative one, not qualitative. Here, Willis appears to ask for quantitative argument rather than “hand waving”, but his inadequate counter arguments listed on the previous blog are also qualitative “hand waving”, so I don’t feel the need to do otherwise. Springer answers most of them very well.
Yes, TallBloke allows a greater latitude about what’s acceptable to explore on his blog, and I think he is well aware that some discussions are really pushing it. But this argument does not come under the same category of the N&Z hypothesis [which I don’t subscribe to].
Be that as it may, Willis posts a blog here discussing that ocean surface temperatures appear limited, and it’s an interesting point. Eye-balling the data, I can’t see a significant difference between maximum surface temperatures in tropical open oceans in the Northern and Southern hemispheres. Despite the fact that the southern hemisphere receives, I think, about 7 to 9% more insolation, this won’t surprise many people who are already persuaded that the temperature of this planet is ruled primarily by the sun and water, not carbon dioxide.
Rosco says:
February 12, 2012 at 1:44 pm
How about this –
The AGW proponents have it totally wrong – the Sun’s radiation warming the Earths’ surface is not the measly 170 W/sq m 24/7 as deceptively stated but wayyyy more during the day.
The atmosphere and oceans REDUCE the surface temperature during the day to much lower than it would otherwise be – evidence: the day temperature of the Moon with no atmosphere shows the Sun’s radiation could fry us during the day.
I can never understand the dismissal of this important fact – without an atmosphere and water we’d all be burnt to a crisp by the Sun’s radiation.
Well, they’ve taken out all the direct heat, (beamed) thermal energy, from the Sun from their energy budget saying it doesn’t reach the surface, could this have something to do with it?
To me it seems likely that CO2 released from warmer ocean waters is the most significant source of increasing atmospheric CO2 and may be a “safety valve” mechanism for a global thermostat providing extra radiative transport for heat to space and actually providing no radiative forcing – not a positive one anyway.
CO2 is part and parcel of the Water Cycle, which has also been taken out of their energy budget, and this brings the temperature down by 52°C to 15°C from the 67°C it would be on an Earth without water, but with its atmosphere of nitrogen and oxygen (and trace). The difference then it appears between the moon and earth from the 67°C and whatever the moon’s, is the difference between with and without dry atmosphere.
So, how would you calculate what it would be rather than the 170 W/sq m 24/7 ?
Septic Matthew says:
February 12, 2012 at 12:25 pm
Yes it is, Matthew, sorry for the lack of clarity.
w.
PS from E.Thomas. I forgot to mention. On the northwest coast of Australia there are no substantial sea breezes from the Indian Ocean as there are from the Pacific in the east. Consequently coastal land temps are often 10*C hotter than the east. Down south near Perth during the summer afternoons a reliable sea breeze affectionately known as the Fremantle doctor (Fremantle is the port for Perth) kicks in to moderate temperature. Cheers (again)
O H Dahlsveen says:
February 12, 2012 at 1:26 pm
Upwelling.
w.
AdolfoGiurfa says:
February 12, 2012 at 3:08 pm
Indeed it does imply that.
w.