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:
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OK I can’t help it. It’s like a flame to a moth I guess.
I just saw on the news where there was a CO2 pool over in Tampa after a long still night. Thousands dead! Film at 11….
“I wasn’t aware of radiation being mentioned in the gas laws.”
Of course not. The Gas Laws describe non radiative processes and they are the processes one needs to know about when dealing with one grey body attached to another grey body with no vacuum in between, such as a planet and its atmosphere.
“I don’t recall him discussing a convection breakout at night under the influence of down-welling radiation.”
I never said he did and it isn’t necessary. Simple warmth at the surface when the higher levels cool at night is quite sufficient. The ITCZ may be less intense at night but it doesn’t disappear.There is no downwelling radiation, merely residual warmth at and just above the surface as per the Gas Laws.
I never denied the SB equations either which is why I initially ignored your question about it. SB simply isn’t what matters in a planet/atmosphere interaction. SB has to be applied outside the influence of any atmosphere. If you try to apply it within an atmosphere then obviously it will not hold. You might as well try to apply it 10 metres below a solid surface. Utter nonsense.
I don’t agree with all that Myrrh said but he has pinned down the fact that you and Willis have a science fiction view of the real world.
Goodbye.
OK Paul – you’re toast.
Now, the reference I’m giving a link to has a two-fold purpose for me, one to show that in the real world and not in the science fiction world promoted by the AGWSF meme production department, carbon dioxide is heavier than air, which means that it is constantly displacing air travelling down to the ground unless there is work being done to move it, wind and so on, and two, to point out another fictional to the real world meme from that department. Hopefully you’ll take this on board and it will help you see more of the misinformation, that this will draw back the curtain for you if only a bit.
http://hvo.wr.usgs.gov/volcanowatch/2005/05_06_02.html
“Usually the large amounts of carbon dioxide released by Kilauea get dispersed by winds so we can breathe nice, healthy, oxygen-rich air on the caldera floor. Because CO2 is heavier than air, it doesn’t readily rise into the atmosphere and, instead, tends to pool in low areas. In the summit caldera these areas include underground openings, such as lava tubes, pits, and underground vaults. In such places, simple filter masks cannot protect individuals from asphyxiation.
..
Better known but less related to active volcanism was the overturn of Lake Nyos in Cameroon, West Africa. Several lakes in this region are nestled in old volcanic craters. In these lakes, carbon dioxide from cold springs built up in the deepest lake waters. In 1986, gas suddenly bubbled out (possibly initiated by a landslide into the lake), flowed downhill, and asphyxiated about 1,700 people.”
Now, read my bold a few times. This is a description of the real world. This is why I was right in the thought experiment, and the PhD in physics supporter of AGW was utterly and completely teaching fictional fisics. Do us all a favour, understand what this means.
Now, read the last sentence of the first paragraph again – note particularly well the word used “asphyxiation”. Carbon dioxide in large amounts is dangerous because it displaces air, it is lack of oxygen which kills, not the carbon dioxide.
Now, read the following in this piece.
“Carbon dioxide (CO2) is a colorless, nearly odorless gas that is denser than air. While toxic at very high concentrations, it can kill at lower concentrations by displacing oxygen, causing asphyxiation. CO2 makes up less than 1 percent of the air we normally breathe in and about 4.5 percent of each breath we exhale. Breathing air that is more than 7 percent CO2 can produce unconsciousness in just a few minutes.”
See if you can spot the AGW science fiction fisics meme.
“While toxic at very high concentrations” is complete bullshit. It is not a toxic gas, it kills by asphixiation at very high concentrations, as the rest of the piece accurately describes. Carbon monoxide is toxic, and in traditional physics is so designated, but carbon dioxide is NOT TOXIC. This meme “is toxic”, is another produced by the AGWScience Fiction department, to demonise carbon dioxide, to confuse those who don’t know any better.
There was a campaign produced by this AGW department a few years ago to get carbon dioxide put on “toxic and hazards” lists – it was successful in some countries. This is all because the purpose of creating AGW was to demonise coal, by other fossil fuel industries and nuclear. You’ve been had.* It’s continually repeated to make you believe it is real, ‘clean’ energy contrasted with ‘dirty’ coal, the cheap fuel source. Watch out for these memes, you’ll find them easier to spot the more you come to appreciate that they have created a completely fictional fisics.
You don’t understand the physics of the real world because AGWSF has taken you through the mirror with Alice, into an impossible fisics world, and all by small, subtle twists of real physics; by swapping around properties and processes, here by taking away the properties of weight and volume of real gases and replacing them with the fictional ideal. This is but one example. This is why you don’t understand convection and conduction, because your atmosphere has no volume or weight. Your world is empty space – you need to put real molecules back into it to hear what I’m saying.
*AGW has always been funded by anti-coal industries, they deflect from their involvement by the meme “sceptics funded by fossil fuel”, CRU was set up by these, set up to mess with the world’s temperature records, as discovered in New Zealand.
The AGWSF ‘energy budget’ you all use, KT97 and variations, is total codswallop – you just can’t see it’s science fictional fisics because the brainwashing has been successfully introduced into the education system. We now have a whole generation who haven’t the faintest idea how the world around is in real physics.
Sorry but it’s not really news that CO2 is heavier than O2. That’s what the C is for. And yes, N2 is lighter than O2. So it’s relatively heavy stuff. It is also scarce and while you can certainly overwhelm its diffusion by spewing out large quantities of it that sink and pool for a while, these events are not going to impact global climate.
A pool of CO2 in a caldera is not going to make it warm in Honolulu.
And BTW I don’t give a rip about the definition of toxicity in physics. In medicine CO2 can be toxic. So can Oxygen and Nitrogen for that matter.
Paul Bahlin says:
February 20, 2012 at 5:20 am
Sorry but it’s not really news that CO2 is heavier than O2. That’s what the C is for. And yes, N2 is lighter than O2. So it’s relatively heavy stuff. It is also scarce and while you can certainly overwhelm its diffusion by spewing out large quantities of it that sink and pool for a while, these events are not going to impact global climate.
There are two points about Carbon Dioxide being heavier than air. Firstly, it shows the nonsense that AGWScience Fiction fisics says about it, that it is ‘well mixed because it diffuses in the atmosphere as per ideal gas law’ and ‘it accumulates for hundreds and thousands of years’. Secondly, that weight means gravity means volume, all that which ideal gas doesn’t have – our atmosphere is not empty space with radiation the only method of heat transfer, but a real molecule heavy, voluminous, fluid ocean of gas above us, pressing down a ton per square foot; a real atmosphere where conduction and convection are in play – especially in any upwelling from diffuse heat, as contrasted with the direct straight line heat from the Sun to Earth thermal energy on the move by radiation, which the fictional AGW energy budget has excluded anyway.
A pool of CO2 in a caldera is not going to make it warm in Honolulu.
? So you weren’t actually following the discussion?
And BTW I don’t give a rip about the definition of toxicity in physics. In medicine CO2 can be toxic. So can Oxygen and Nitrogen for that matter.
Bullshit, none is toxic in medical science. The definition comes from medical science physics. Toxin means poison, these are not poisons. Oxygen and nitrogen are practically 100% of our atmosphere! You’re an example here of sucessful brainwashing by the AGWSF department. Your rational thinking has been compromised by their memes.
Willis;
Sorry, don’t have the link to hand right now, but saw a plausible explanation of the “~29°C” SST maximum recently. Ties in with your tropical thermostat, too.
Seems that at about that temperature the power of conductive and latent heat energy transferred to the covering air column is enough to initiate vigorous convection, usually leading to storms etc. which inject excess energy into the circulation system’s hi-speed distribution system. A kind of “threshold effect”.
http://www.qrg.northwestern.edu/projects/vss/docs/thermal/1-how-does-heat-move.html
“When there is heat at the bottom of this air or water, the air or water molecules in contact with the heat start to move, and the molecules spread apart. The heated air or water becomes less dense. It rises up until it gets to air or water with the same density as it has, and when it gets there, it pushes the air or water that was there out of the way. At the same time, new air or water fills the space that was vacated when the heated molecules rose up. The air or water that gets pushed out of the way falls down. This sets up a circular motion. Air or water is heated at the bottom, travels to the top, cools, gets denser, falls, is heated again and the whole cycle starts again. Convection does not occur in space because there is no gravity.”
AGWSF doesn’t have gravity because it bases its energy budget on an atmosphere of empty space, not the real heavy volume of fluid gas we have around us. That’s why none of you understands what convection or conduction have to do with this.
“Radiation happens when heat moves as energy waves, called infrared waves, directly from its source to something else. This is how the heat from the Sun gets to Earth.”
What about regressing each Argo-floats:
direction and speed on its position and temperature
We would measure the upwelling and the stremm away from the equator, both cooling the equatorial water.
From your observation I would expect a fast increase in speed at 25-30 centigrades.
Willis Eschenbach says:
February 13, 2012 at 12:20 am
Stephen Wilde says:
February 12, 2012 at 11:30 pm
… Surface air pressure determines the amount of heat (or rather energy) flow that one gets from a given temperature differential.
The higher the pressure at the surface the higher the temperature needs to get at the surface to enable convection to overcome the weight of air pressing down on the surface.
The Gas Laws prevail.
Anti-scientific hogwash. I’ve asked you before and I ask you again to take your ridiculous pressure theories to Tallbloke’s Talkshop. They have no place in a scientific discussion.
————–
Steven – please see my post on The Skeptics Case where I’ve linked to some of your posts here:
http://wattsupwiththat.com/2012/02/26/the-skeptics-case/#comment-911396
Fascinating.
I have read the entire exchange, and while I have come no closer to understanding the science, I have retained my confidence in my bullshit-meter which flashes and hoots at the obscurantist smoke of pseudoscience. And it’s been going, bwaa-bwaa-bwaa-bwaa!.
The alarms with the flashing and hooting occur during the following: When critiques are interpreted as personal challenges which somehow damage the entire field or the personal dignity of the author. When we are told to think on a presumably higher plane, by being imaginative or poetic. When exceptions are paraded as evidence, as in, “well, look at Galileo, Lister….etc. When we are urged to provide support, kindness and good thoughts, in lieu of critiques. When the argument from authority rears its stupid head in the middle of a debate and some people, quite selectively, are suddenly asked to supply credentials. And, when all this crap takes up over 90 percent of the discussion, while challenges and questions regarding substantive issues are left unaddressed.