Further Evidence for my Thunderstorm Thermostat Hypothesis

Guest Post by Willis Eschenbach

For some time now I’ve been wondering what kind of new evidence I could come up with to add support to my Thunderstorm Thermostat hypothesis (q.v.). This is the idea that cumulus clouds and thunderstorms combine to cap the rise of tropical temperatures. In particular, thunderstorms are able to drive local temperatures to a level below that necessary for thunderstorm initiation. This allows them to act as a true governing mechanism.

Recently I came across a fascinating study by Zeng et al called “A Multiyear Hourly Sea Surface Temperature Data Set“(PDF). Figure 5 of their paper contains a host of information in three panels, from which I have extracted the average hourly changes in surface temperature in three areas of the Pacific shown below. The information is from moored buoys.

Figure 1. Multi-year hour by hour long-term average surface air temperatures for three areas in the tropical Pacific (2°N 95°W, 0°N 155°W, and 0°N 156°E, shown by colored circles). Two full days are shown, in order to see the complete temperature change during the night.

Note the strange shape of the hour-by-hour temperature record, and yet how similar it is between the various sites. Of course the question arises … where in Figure 1 is the evidence for a homeostatic system regulating the temperature? To investigate that, I looked at the data in a slightly different way.

Figure 2 shows exactly the same data as in figure 1, but shown as anomalies about the average, and only covering one day rather than two. There is information in the similarities as well as in the differences between the three locations.

Figure 2. Anomalies in hourly Pacific temperatures. Locations and colors are the same as in Figure 1. Intensity of the theoretical clear-sky solar energy at the surface (surface insolation) is shown by the line running through the sun (right scale). Blue oval shows general cumulus initiation time, green oval shows thunderstorm initiation time, and the brown oval shows the cloud dissipation time.

Let me give the timeline of the tropical day that is shown in Figure 2, pointing out the important time periods.

At dawn the day is clear and the air is calm. As a result, the air temperature starts rising quite quickly after sunrise.

As the day warms, at some point before noon a threshold is passed. Cumulus clouds (the small puffy white summer clouds) start to form, and the lower tropospheric circulation switches to a new pattern. The cumulus clouds can be thought of as flags that mark an area of rising air. Around each of them, there is a ring of descending air. This change has a couple of immediate effects.

The first is an immediate reduction in the incoming solar energy because of reflections from the cloud tops. This is accompanied by a rise in the surface wind. Since the evaporation varies linearly with the wind, if the wind doubles from 1 metre/second (2 knots) to 2 metres/second, evaporation doubles. This also cools the surface.

As a result of the changes in the lower troposphere, from calm with no clouds to increasing numbers of circulation cells with cumulus clouds, in the central and western Pacific the temperature actually starts dropping. This is happening despite the continuing increase in the amount of incoming solar energy (negative climate sensitivity, go figure). In the eastern Pacific, the air (and the ocean) is much cooler. As a result the cumulus coverage is less complete and develops more slowly, and the temperature rise is not reversed, but the temperature rise is significantly slowed.

However, even in the western and central Pacific the steady input of solar energy overwhelms the cumulus, and the temperature starts to rise again. At some point, usually early afternoon (and earlier in the day if the temperature is warmer), another threshold is passed and thunderstorms start to form. The temperatures continue to rise, but at a much slower rate than earlier in the day.

At some point in the late afternoon, the amount of incoming energy is less than the amount of outgoing energy, and the air starts to cool. It is aided in this cooling by the thunderstorms, which in warmer seas often continue until several hours after dark.

After the sun goes down, of course, clouds have a warming effect because they greatly increase the amount of downwelling “greenhouse” radiation. This can be seen in the kink in the curve between about 19:00 and 21:00 hours.

Once the clouds dissipate, however, the air is much freer to radiate out to space, and rapid cooling sets in which lasts until dawn. By that time, there are no clouds and the atmosphere is generally calm … and the cycle starts over again.


There are two main effects to having this daily cycle. The first is the rapid warming in the morning. The second is the abrupt slowing, and in warmer waters the reversing, of the rapidly rising temperatures by clouds and thunderstorms. These effects work together to keep the daily temperatures within a fairly narrow band.

The differences between the three locations are revealing. The onset of the cumulus is nowhere near as effective at preventing the temperature rise in the warmer waters of the western Pacific “hot pool”. In this warmer area the temperature starts rising again around noon, where in the central Pacific this doesn’t happen until about 2PM (14:00). In the much cooler waters of the eastern Pacific, on the other hand, it appears that not many clouds form, and the result is to push the peak daily excursion higher than that of the warmer waters. And because there are fewer thunderstorms in the cooler eastern Pacific, the temperature stays warmer after dark and does not show as pronounced a kink after dark.

Also, in the hottest region the peak temperature occurs earlier in the day than in the two cooler areas. Presumably this is because of the more complete development of the thunderstorm regime in the warmer waters, leading to more rapid cooling.

One unexpected curiosity in this data involves the fact that it takes energy to warm the air. If we start at the coldest point in the day and sum the temperature anomalies around that point, it will give us a relative measure of how much energy it took to warm the air during the 24 hours.

Here’s the odd part. Despite the differences in the local average air temperature, all three areas warm the local air the same amount, within about ± 5%. I have no idea why this might be so. Whatever the combination of clouds and thunderstorms is doing, it leads to about the same amount of warming of the air in all three areas. I have no idea why.


The hourly air temperatures over the tropical Pacific show a clear pattern that is due to the specific timing, formation rate, and number of cumulus and cumulonimbus (thunderstorm) clouds. This pattern is completely congruent with the idea that cumulus and cumulonimbus clouds act as a homeostatic mechanism to prevent the oceanic air temperatures from getting too warm or too cold.

I have not yet taken a look at the underlying dataset, I’m sure that there’s much more to learn. So to make this an official science paper, let me say that additional studies are needed …

All ideas welcome, be nice, attack the ideas all you want but please don’t attack individuals or cast aspersions on motives. That angrifies my blood mightily and I tend to do things I later regret. I’d prefer to avoid that.

Best regards to all,


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Addison DeWitt
June 7, 2011 12:16 am


June 7, 2011 12:16 am

Presented with the utmost clarity as always. Thanks, Willis.

Paul Deacon
June 7, 2011 12:17 am

Good article, Willis. Keep up the good work.
Might a comparison with sea surface temperatures be worthwhile (or at least interesting)?

richard verney
June 7, 2011 12:21 am

I can see that there may be merit in your general proposition that thunderstorms could act as regulators. That proposition makes quite a lot of sense. However, as regards this analysis, I would not wish to read too much into such sparse data and where is the evidence that there were any thunderstorms at any time over each of the three locations? What you show may be nothing more than the effects of behavioural patterns of typical cloud formation (although there is no quantative data of precisely what clouds were forming and their pattern and constitution over each of the three locations) and therefore not demonstrating the effects of thunderstorms,
That said, the graphs are as Spock would say ‘fascinating’

June 7, 2011 1:13 am

Willis, a possible further mechanism to add to your Thunderstorm Thermostat hypothesis :
I first came across these in a rather breathless brief TV documentary back in the 90s. It made the basic point that, although we didn’t know much about them, these upward-bound lightning strikes are happening all the time above big thunderstorms.
While each lightning strike is, of course, of very short duration, they are of massive power, and they are happening a lot, and all the more when there are more thunderstorms.
It seems to me that these represent a significant energy flow between the top of the thunderclouds and the top of the atmosphere.
I would be interested in any thoughts on whether this could be a significant part of the regulatory mechanism.

June 7, 2011 1:37 am

Intriguing. I’m sitting here in the tropical Western Pacific where a thunderstorm initiated around 3pm and lo! the temperature did drop! Rather timely of it. I was starting to swelter.

June 7, 2011 2:06 am

As usual from you, Willis, very interesting observations. Thanks again.

Dave Eaton
June 7, 2011 2:34 am

Very interesting.
Do you think there is any connection between numbers of GCR’s and the extent of cumulus clouds and thunderstorms? If there is, then your “governing mechanism” could well go beyond regional and into global temperature significance and could be evidenced in the comparison, of the same daily temperature records that you have used, at times of high and low sun activity?
The way I see it, is that numbers of GCR’s increase when the sun becomes less active. Now, the GCR’s cause a growing avalanche of electrons within the clouds or thunderstorms, and when the numbers of GCR’s increase too(see link below) the growing numbers of electrons increases the condensation process, liberates more heat, grows the storm, increases albedo, makes for bigger downdraught’s and reduces air temperatures. One could postulate that this is the cause of small but significant earth temperature changes
In effect, the mechanism normally acts as a negative feedback to global warming and periodically, a forcing mechanism for global cooling?
see this report on lightning research – http://physicsworld.com/cws/article/news/39381

John Marshall
June 7, 2011 2:44 am

Having lived in the Tropics I can tell you that a good thunder storm certainly cools things down by several degrees C. Most welcome some days.

TFN Johnson
June 7, 2011 2:45 am

Freddy has made a comment about upward lightning.
A few months ago there was a report that anti-matter had been detected in thundersorm clouds.
Might there be any connection?

June 7, 2011 2:46 am

Thank you Willis. You make me think about things I have simply taken for granted all my life.
To this end it’s all a bit mind boggling but I am trying to understand.
“At dawn he day is clear and the air is calm. As a result, the air temperature starts rising quite quickly after sunrise.”
The location is over the ocean, the ocean surface heats up that quickly to warm the air? Or is it our favourite GHG H2O and some help in the 4.7 micron band from CO2 warming the air via the near infrared from the sun and thus denying that energy to the sea below?

kadaka (KD Knoebel)
June 7, 2011 2:51 am

Editorial notes:
At dawn he day is clear and the air is calm.
Missing a “t”, unless you’ve neglected to talk about the matching she day as needed for an “equal time, balanced” presentation. She who must be obeyed might get upset.
Once the clouds dissipate, however, the air is much freer to radiate out to space…
We lose more atmosphere to space? Or should that say “…the heat is much freer…” or “…the air is much freer to radiate the heat out…”?
The two quibbles aside, good piece.

June 7, 2011 2:54 am

Hah! I lived in Singapore for three years and can confirm the afternoon thunderstorms. They were a blessed relief. The readily available gaily painted oiled paper brollies were for wimps. 🙂

June 7, 2011 3:04 am

Willis writes:

“Well, I developed this hypothesis based on the 17 years that I lived and worked in the tropics. For eight of those years, including the time when I actually formed the hypothesis, I lived in the Solomon Islands, which are the yellow dots in Figure 1 which are just below the red circle marking the western Pacific data. “

You mean to tell me that you based your hypothesis on observation?
Sir, this is NOT how climate science is done, you didn’t even use a computer model! /sarc
My best suggestion: you need to turn this into a formal paper, and explore all avenues and datasets for further support. In fact, since the signal is so consistent with longitude, I suggest that you could in fact model it and see what happens when the base average temperature increases/decreases. My thinking is that the ITCZ would simply expand/contract in latitude to compensate. A model might confirm this, as might a look at long term satellite data.

Joe Born
June 7, 2011 3:05 am

I’m not sure I understand the statement that “we start at the coldest point in the day and sum the temperature anomalies around that point, it will give us a relative measure of how much energy it took to warm the air during the 24 hours.” Given that clouds form earlier in the hotter regions, isn’t it plausible that latent heat (i.e., heat not reflected in temperature) is a bigger factor in those regions than in cooler ones?

Geoff Sherrington
June 7, 2011 4:02 am

Willis, completely in qualitative accord with my years in North Queensland.
Here is some stuff from Jabiru, Northern Territory, that might assist. I wish I had more of this, but I had to junk it when I left employ. It’s soil temperature 40 mm deep (which smooths the result) taken over 3 days at irregular intervals of a couple of hours. From memory, it was after the Wet season because we wanted other measurements to be in the Dry, though some late afternoon clouds do form.
Have you smoothed the graphs? If not, the fine texture of hour-to-hour would be interesting. The East Pacific point is approaching the dry west edge of Sth America. Is it possible that total rainfall drops off as you go east over ocean after ocean, with little to lift the air to precipitation mode, like mountains? This might be part explanation of the dearth of morning clouds in the East.
Nice work, again.

June 7, 2011 4:07 am

I have been thinking along these lines for a while, but the thermostat has a little hysteresis. Tropical cyclones are pretty good size thunderstorms that would seem to be part of the system. There is not a great correlation of ACE and temperature. That is not disproof of the thunderstorm thermostat, just that something is missing. I think that something is tropopause interaction. Tropical storm activity releases a lot of heat, but should release much more in the higher latitudes where the tropopause is lower.
The northern tropopause varies considerably more than the southern in altitude and the minimum temperature of the tropopause in the subtropics varies quite a bit (down to about -95C around latitude 30N). So where the convective activity occurs should have a significant impact on total heat transfer. There is too much overlap in the RSS and UAH products to really follow the tropopause well enough to make any solid conclusions, but there are some interesting oddities in the surface temperature record. Like a 2 to 3 C step up in Scandinavia in the late 80’s that persisted, the differences in la nina impact on temperature.
Some natural oscillations have more temperature impact than others, that may be due to the different tropopause interactions.
Anyway, it is over my head, but interesting.

Joe Lalonde
June 7, 2011 4:16 am

I value a mind that is not bound to the current science generalized laws that is seeking innovation and understanding in an area they find interesting and fascinating.
I study a huge area of planetary rotation which I have to incorporate many sectors of study from the suns input of energy to the shape of our planet to density changes of planetary slow down spanning billions of years. Hundreds of drawings of how individual energy interacts, magnetic field interactions and the phenomenon of the sun in sequence with rotating planets that are only one day difference out of 4.5 billion years(except 3 planets).
Here is what may help you.
The area is highly complex of the rotating suns biggest density is it’s equator. Hence, it is the closest area to Earth. Giving off individual particles of charged gases and different heat/radiation through the vacuum of space.
Next, our atmosphere catches the suns energy in varying degrees to the shape of the atmosphere as it rotates. The biggest area is our equator as the planet is smaller to the poles. Angles of energy from the sun is deflecting and having varying degrees of length of travel through the atmosphere also, adding in, the planets tilting as the planet rotates for the day/night cycle.
Now add in the different gases at different level plus cloud cover.
I believe the atmosphere can change the intensity of the heat coming in by the angle it goes through.
What evidence? The illusion of a bigger looking sun in the morning and evening hours.
Hope this helps and not confuse.

Tom Harley
June 7, 2011 4:24 am

Nice article, thanks Willis.
About 12 or 13 years ago we in Broome were hit by a super thunderstorm that started at around 8.30 pm. Lightning struck everywhere around town, almost continuously, for 4 to 5 hours. There was no wind, but it absolutely bucketed down with rain. Every time you thought it could not get heavier, it did. At the end of the rain about 1 am, we had received about 20 inches (500mm) of rain, forever after called ‘The Deluge’. This small system then crossed the continent, even bringing heavy downfalls as far away as Eucla on the south coast and South Australia.

June 7, 2011 4:45 am

I believe the basic premise of this article makes a lot of sense. This is also why I also believe there must be some mechanism (perhaps water vapor related) in the upper troposphere that allows the heat energy convected up there to be eventually radiated directly to outer space. Otherwise convection could not be considered a cooling mechanism for the Earth if upper-altitude heat had to be returned to the surface before it could actually be radiated to outer space.
I believe this proposal also requires the -55 degree C temperature of the tropopause to be, in some way, forced by the properties of the atmosphere and be largely independent of the ground temperatures because this sets the effective ground temperature control limit via the lapse rate.

June 7, 2011 5:05 am

One possible testable effect would be a change in the temperature curve for the eastern pacific base on el Nino, la Nina. In warm conditions I would think the eastern pacific curve would start looking more like the central and become more extreme in la nina.

June 7, 2011 5:11 am

“Despite the differences in the local average air temperature, all three areas warm the local air the same amount, within about ± 5%. I have no idea why this might be so. Whatever the combination of clouds and thunderstorms is doing, it leads to about the same amount of warming of the air in all three areas.”
The same sun shines on all three locations. The data is averaged over a long period. So this is support for the idea that the mechanisms which maintain temperature within bounds have redundant capacity. It would be even stronger support if the relationships held over quite short time periods or sets of randomly selected day data (same date for each location but random days of year).

June 7, 2011 5:15 am

How does this relate to Trenberth’s observation (and, really, the general positive feedback of more h20 capacity) re warmer air in a warming world holding more water vapor to start with? What would we expect to see over time if this mechanism is actually functioning –either sooner storm initiation or longer storms, or both? Any evidence that is happening? To be a little naughty, to what degree are you concerned you’re actually confirming their “warmer world = more extreme weather” hypothesis from another angle?

June 7, 2011 5:19 am

Willis Eschenbach says:
June 7, 2011 at 3:38 am

Willis, thank you for that response. Looks like I’m thinking on the right lines but as usual much more to think about. 😉

don penman
June 7, 2011 5:21 am

We don’t have so many thunderstorms in the UK and it is certainly not a daily occurrence here not even in summer,we see more variability it can either be cool and wet or it can be dry and hot.The cause of this variability could be the surrounding sst when it warm and evaporation is high we get more rain.In the mid seventies we had our warmest summers when The Northern hemisphere was having cold winters.

mike restin
June 7, 2011 5:30 am

You didn’t mention where you got the funding for your research and if you expect the NSF, NOAA, NASA or CRU might assist with further investigation and more funding.
Any researcher knows it’s the most important information in any peer reviewed paper.
How else will others know where to go to get free money.

June 7, 2011 5:38 am

Another excellent article. Living here on the continental divide between the Eastern Pacific and Western Caribbean, 9 degrees above the equator and at 4,200 feet, we have a bird’s eye view of the weather action, just as you have presented it. One of our great questions is the almost unbelievable stability of the temperature. Over the last week for example, it has varied between 55 and 70 F, day and night, year around. Here is an excellent data set from a very well maintained (and properly sited) weather station in Palmira at about our same altitude. It confirms exactly your presentation.
So, while the temperature is extremely stable, rainfall varies wildly, both from day to day and year to year. I don’t know enough about the mechanics involved, but I am pretty sure that there is a clue in all this about how the thermostat works.
It also occurs to me that if one wants to study global warming, one should look to the most stable region of climate on earth for evidence of changes (is the thermostat going up or down?) rather than the chaotic Northern latitudes. It’s a little like trying to understand the laminar flow that keeps an airplane aloft by studying the wake turbulence.

June 7, 2011 5:57 am

Willis :
I’ve run the numbers on the energy in the lightning strikes, it wasn’t impressive compared to the energy released by the raising of some kilotonnes of water a few km into the air and dropping it back down.
I was afraid of that. Oh, well.
If ever you feel so inclined, I would be fascinated to see what numbers you were able to come up with for lightning.

Steve Keohane
June 7, 2011 6:06 am

Thanks for this Willis. As one who spends as much time as possible outdoors, your observations seem an obvious perception, one greatly lacking in the ‘desk jockey’ modelers. With all the variables that go into it, and I assume we do not know them all, the climate is remarkably stable on our planet. Proof of this is the existence of the life forms on it.
One typo I noted: the word ‘cirrus’, you may have meant ‘cumulus’?
The onset of the cirrus is nowhere near as effective at preventing the temperature rise in the warmer waters of the western Pacific “hot pool”.
[REPLY] Thanks, fixed. w.

June 7, 2011 6:13 am

Willis, data for cloud coverage and rainfall, if you can get it, would help to quantify the amount of energy flowing in this system. No doubt you will find a Constructal Law principle in play with flows taking the most efficient paths at particular hours of the day.

Gary Swift
June 7, 2011 6:39 am

Wilis, always fun reading your stuff. I usually agree with you, but not this time.
Your own statement and evidence seems to contradict your theory. The fact that the total daily anomaly is the same, even in different regions where cloud formation patterns are different, seems to indicate that the sun is the only regulator. Now, if you saw a plateau at some level of max temp, then I would agree with your idea of clouds acting as a self-contained regulator. But that’s not what we see. The max daily temp peaks at the same level regardless of the clouds in each region. It just changes the rate of incline and decline and the time of day when max temp is reached. I do think it is curious to see how the time of day for max temp is shifted towards the PM by the clouds though. That might have an ancillary effect of retaining more heat into the evening when the clouds act as a positive feedback, so in that regard the system is also self regulating to shift the time of day for min temp.

Hans H
June 7, 2011 6:44 am

I think the Thunderstorm Thermostat Hypothesis is very interesting.
There seems to be a more rapid heating during mornings in the west than in the east. Could that be because the air in the west in early mornings is slightly dryer, after more frequently having experienced thunderstorms the day and or night before, than in the east?

June 7, 2011 6:56 am

Willis, you may have seen the presentation to KNMI http://climategate.nl/wp-content/uploads/2011/02/CO2_and_climate_v7.pdf by Dr Van Andel, who authored a very readable paper on Miskolczi’s theory in the same issue of E&E as your paper. Van Andel is a chemical engineer very familiar with heat transfer (particularly convective heat transfer and phase change). The first part of the presentation, based on measured data, could fill in some gaps. Maybe, you could co-author a paper.
keep strong
PS The presentation is a translation (I believe by Dr Van Andel). I note that in a few places there is a Dutch/German tendency to put the verb at the end of the sentence.

Hans H
June 7, 2011 7:02 am

Sorry, I meant EARLY mornings ( 6-9 am) in the second statement in my comment above.

June 7, 2011 7:03 am

Willis, as usual you are a treasure and a pleasure to science. I very much appreciate your openness and willingness to discuss points that surround your main treatise.
I think that I see a temperature relief valve near the Tropopause that uses water vapor and carbon dioxide as the regulating mechanism. The observation is the measured drop in specific humidity since 1948 at various elevations, including 300mb. As Troposphere temperature rises the percentage of water vapor starts to increase. As carbon dioxide increases it displaces water vapor due to lowering the partial pressure. The water vapor is then lost into outer space allowing more water to be evaporated at the surface at constant temperature. The evaporation process changes the potential energy of the liquid water to kinetic energy which absorbs the latent heat. As the new water vapor rises due to lower molecular weight, it condenses and transforms the kinetic energy back to potential energy. During the condensation step, the water gives up the latent heat from the evaporation as specific heat and thus cools the atmosphere.
I suspect that the earth has several “relief valves” given the crude heat transfer mechanism of using the the oceans to convey heat from the tropical areas to the polar areas. This heat transfer process undoubtedly has overshoots and undershoots, which trigger the various relief valves. Some of these relief valves may function as “control valves” that operate in both directions.

June 7, 2011 7:14 am

Nice curves Willis .
Like I said after your first post about this issue , I think that the system works like that indeed .
However I have still the same problem .
What is new/interesting in that observation ?
I mean that with or without thunderstorms the temperature would have this sinusoidal shape .
Then you add a delay due to the heat capacity of the ocean .
Finally you deform the sinusoid by modulating the heat absorption by clouds .
For instance write just (everything for 1 m²) :
dEa/dt = (1-a(t)) . b . sin(wt) – absorbed radiating power with a(t) cloud cover
dEe/dt = S.T(t)^4 – emitted radiating power where T(t) is SST
dQl/dt = L.dm/dt – latent heat of evaporation of a mass dm
dQw = M.Cp.dT = Ea – Ee – dQ1 where M is the water mass considered for heating/cooling
Now as you see in this simplified case the condensation heat returned to the atmosphere during the rain is taken for 0 . Only evaporation counts because one can consider that most of the condensation heat would not return to the ocean where the temperature is measured . Or one could take a fraction of it . Whatever one likes .
Then :
1) You play with different a(t) thus simulating different cloud cover evolutions – e.g
a(t) = 0 during the night then linear to a maximum , then horizontal then down to 0 again .
2) For the evaporation as you don’t know dm/dt , you can use as first approximation that dm/dt is proportional to the absorbed power (e.g K.Ea) . This means the more sun , the more evaporation . Sounds acceptable . Try different K .
3) M (the amount of water heated/cooled in a 24 hour cycle) is a bit more difficult .
But as we just want to consider steady states , that implies that M is a constant .
In a steady state heat travels up (night) and down (day) over a constant depth H .
So you evaluate H for a 24 hour cycle and then M = 1000H (units kg/m²)
With 1+2+3 above you just constructed a model that describes quantitatively your qualitative thunderstorm/warming/cooling 24h cycle.
You will see that with K and a(t) as the only degrees of freedom , you will probably get a good fit to the temperature curves by solving the differential equations above .
In other words you have a working simple model of tropical SST on a 24h scale that exhibits the behaviour you described .
But then the question is again what’s new and or interesting with the equations I have written above ?

Ian W
June 7, 2011 7:19 am

Here’s the odd part. Despite the differences in the local average air temperature, all three areas warm the local air the same amount, within about ± 5%. I have no idea why this might be so. Whatever the combination of clouds and thunderstorms is doing, it leads to about the same amount of warming of the air in all three areas. I have no idea why.
To add to Tallbloke’s response, I think that you are measuring the effect of solar heating on the hydrologic cycle so you see very similar values and patterns from metrics taken at similar latitudes over the pacific. I suspect that measures taken at similar latitudes in the central Atlantic may show the same pattern and magnitude. Perhaps there are figures from Ascension Island that you can use.

June 7, 2011 7:27 am

From my time growing up in South Louisiana during the summer time, we experienced the same temperature regulation. In morning would be cloudless and by 2-5 pm thunderstorms would build and limit the temperature to around 92°-95° F as a high then as thuderstorms built would cool into upper 70’s to mid 80’s. I agree with his theory.

David Chappell
June 7, 2011 7:41 am

The main village on my little island in Hong Kong has a very expensive (US$40K) combined digital clock and temperature indicator. In absolute terms I suspect the temperature indications are not particularly accurate because of siting problems. However, last summer I was sitting having a beer with a friend as a massive storm approached. As the rain hit (and, boy, did it hit) the temperature indicated dropped by 4C in about 3 minutes. A pretty good demonstration of the air cooling power of storms.

R Taylor
June 7, 2011 7:43 am

I’ve never seen a quote on how much energy leaves the earth at 2 kHz and below. Thunderstorms generate broadband EM, and very long wavelengths escape through the ionosphere.

Mac the Knife
June 7, 2011 7:53 am

marcoinpanama says:
June 7, 2011 at 5:38 am
“It also occurs to me that if one wants to study global warming, one should look to the most stable region of climate on earth for evidence of changes (is the thermostat going up or down?) rather than the chaotic Northern latitudes. It’s a little like trying to understand the laminar flow that keeps an airplane aloft by studying the wake turbulence.”
That is a cogent and interesting thought, Marco! Good analogy!

Mac the Knife
June 7, 2011 7:55 am

A very interesting analysis, Willis. Thank You!

June 7, 2011 8:25 am

I have held the view for some time that surface tension is missing from calculations about climate and ssts in particular. The question in my mind was can the sun physically heat the ocean as I have blieved all my life (70).
I held a heat gun over a bucket of water assuming that I would be able to boil the water. After 5 mins I saw no steam and I tested the water. The water was the same temperature as when I started. I repeated the process several times to make sure and was unable get any heat into the water.
The only conclusion I can come to is that the ocean can only be heated by the suns radiation not by the physical heat in the atmosphere over to you. rgds

June 7, 2011 8:27 am

Any Boy Scouts been to Philmont? This weather pattern sound familiar?
In the early ’60s I spent a couple of weeks in northern New Mexico at a Boy Scout ranch called Philmont. It was summer, and we hiked every day from one area to another. Every day it was clear and sunny in the morning. By 11am there was always a few clouds off in the distance (to the north? …been a long time!) By noon it was overcast. By 1pm it was raining. Like clockwork.
While the mechanics are different, the effect was the same, and I’ve never forgotten how stunning the pattern was. My question……is this a similar thermostat?

Tom in Florida
June 7, 2011 9:24 am

“As the day warms, at some point before noon a threshold is passed”
The key would be to find the mechanism that creates this threshold and be able to accurately predict when it will be passed on any particular day. We would then be able to better calculate a tee time in order to get us back in the clubhouse prior to the thunderstorms.

June 7, 2011 10:08 am

I am curious as to weather you have seen the similar work done by Lindzen and Rondanelli, Willis. The examine TRMM and the Kwajalein radar and find evidence for a mechanism like this operating:

June 7, 2011 10:09 am

Haha, got weather on the brain. That should be whether.

Billy Liar
June 7, 2011 10:13 am

You have ignored the reverse of convection that brings cold air down to the surface in the vicinity of a thunderstorm. Entrainment of cold air by the precipitation falling within the thunderstorm causes substantial downdrafts within thunderstorm cells. These can be strong enough to be a danger to aircraft and have indeed caused many airliner crashes. They must be a significant cause of the reduction in surface temperature during the active phase of a storm.
Don’t know how this affects your theory.

June 7, 2011 10:53 am

I’m not so sure there is anything noteworthy here. Accepting your qualitative description of how it works, I’m left with
1. Without math to describe the phenomena we really dont have scientific understanding.
2. The thermostat hasnt keep the planet from warming. that is, unless it changes the way heat eventually returns to space (radiation), then it’s not really doing anything interesting on a global scale.

June 7, 2011 11:19 am

this is getting well developed and the name is good.
phase change, willis – it doesn’t change a temperature.
while evaporating or condensing, water stabilizes the temperature

Antony Nailer
June 7, 2011 11:20 am

Dear Willis,
As you are probably aware I have been carrying forward the work of Dr Noor Van Andel on the effects of water vapour as the controlling factor in global temperature.
I would disagree with the statement that a doubling of wind speed causes a doubling of evaporation. It would be nice to see how that figure was derived. More likely it was just reasoned.
The evaporation according to the formula I have adopted as the one which
most closely fits with experimental data has the evaporation proportional to
(1.316 + U*). Where U* is the surface frictional velocity in m/s.
U* varies by the 0.8th power of the change of wind speed. Let us see how a
doubling of wind speed affects this.
For a typical ocean wind speed of 5.3m/s the U* value is 0.44m/s,
New U* = 0.44 (10.6/5.3)^0.8 = 0.77.
The evaporation previously was proportional to 1.316+0.44 = 1.756.
The evaporation now will be proportional to 1.316 +0.77 = 2.086.
Evaporation will have increased by 2.086/1.756 = 1.19.
Then a doubling of wind speed results in a 19% increase in evaporation.
Definitely not 100% increase.

Matt in Houston
June 7, 2011 12:47 pm

Nice article Willis. We experienced a similar phenomenon this afternoon (&yesterday afternoon as well) here in Houston. Folks around central Florida enjoy this also. Temp rocketed up to around 93 and the nice little thunderstorms rolled in off the gulf and promptly dropped the temp down to about 80. Not quite the same effect that you’re describing, but very similar the way I figure. Houston/KSC might be a decent place to look for data to support your hypothesis…I know local conditions in Houston dont always line up quite as nicely as in the tropics but there may be some good data in quantity available to help flesh your ideas out.

Theo Goodwin
June 7, 2011 12:52 pm

Nice work, Willis. You are attempting to describe a system of natural regularities that might prove to be important to climate science. Those who criticize you seem to forget that Big Warming sends you neither big money nor a lab full of cute graduate students. Clearly, you do not have the means to collect the data necessary for rigorously formulated hypotheses. However, the sort of thing that you are doing is what climate science will look when it is out from under the thumb of the metaphysical modelers. In addition, what you are doing makes wonderful natural history. I wish I had the time and money to do a similar study of Central Florida’s summertime late afternoon showers. The cloud phenomena are very similar to what you describe but the thunderheads form over the peninsula. Thanks again for your wonderful work.

Theo Goodwin
June 7, 2011 12:58 pm

steven mosher says:
June 7, 2011 at 10:53 am
“2. The thermostat hasnt keep the planet from warming. that is, unless it changes the way heat eventually returns to space (radiation), then it’s not really doing anything interesting on a global scale.”
Not everything in climate science is a matter of the planet warming. There are discrete phenomena like thunderstorms and their behavior that must be understood in their own right. To say that climate science is the study of the planet warming is to admit a gross inversion of values. Someday, everyone will realize that, including the Gaia modelers and their CO2 sky god.

Hans H
June 7, 2011 1:26 pm

To expand on my comment (6.44 am):
First, sorry about the spelling error (dryer ->drier; English is not my first language).
Second, I understand that the skies are mostly clear in the early mornings (6-9am) in the Equatorial Pacific independent of longitude. That would mean that the amount of energy transferred from the sun in that period is roughly the same in the three regions mentioned. However, according to the figures above the temperature on average rises more sharply the further west you go in the period. This could be explained by the air, at sunrise, on average being drier the further west you go, as it takes less energy to heat dry air than moist air. But one would indeed expect the air to be drier at sunrise in the west than in the east, as it on average experienced more falling rain due to thunderstorms the day before. (I understand that rain falling through (moist) air leaves the air drier due to condensation.)
If this argument holds, one would, with the data above, have that the average net heat transfer from the sun to the three regions is larger the further east you go. Thus strengthening the hypothesis that if the ocean gets more heated due to changes in forcings (e.g. CO2, the sun) a mechanism (more/stronger thunderstorms) sets in to cool it down. Not necessarily like a governor, it could also be like a negative feedback.

June 7, 2011 2:42 pm

Something doesn’t compute. You show a total daily anomaly of only about 0.8 C. The diurnal variation should be something like 8 C, according to records for, say, Guam: http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/sum2/41415.txt
What am I missing?
Also, where you suggest:
“After the sun goes down, of course, clouds have a warming effect because they greatly increase the amount of downwelling “greenhouse” radiation. This can be seen in the kink in the curve between about 19:00 and 21:00 hours.
I would suggest that at least some, if not all, of that kink is due to evaporation of the cloud droplets and release of latent heat.

June 7, 2011 3:17 pm

Willis: Beautiful job. I loved (truly) your cloud governor hypothesis. This feeds right into that I also spent some time in tropical and semitropical waters. Just a quick question: What is happening to cause the small kinks between 3:00 and 6:00 am. I am sure there is an explanation. Thanks again.

June 7, 2011 3:59 pm

Willis Eschenbach says:
June 7, 2011 at 12:51 am
“…the daily swing of tropical weather (clear at dawn, increasing morning clouds leading to afternoon thunderstorms, clearing after dark) is so common as to be almost a cliché, we used to laugh that they could tape record the weather forecast and just play it day after day …”
There’s an old saying in the tropics: “Just another lousy day in paradise.” From a thermodynamic perspective, it is the thermally-driven moist convection that sets the the entire regulatory process into motion.

Richard Scott
June 7, 2011 5:38 pm

“For some time now I’ve been wondering what kind of new evidence I could come up with to add support to my Thunderstorm Thermostat hypothesis (q.v.). ”
Wrong, wrong, wrong! Searching for evidence to support your hypothesis is not the way science is done. That’s the kind of subjective nonsense we see from the alarmists.
Science is done by TESTING a hypothesis, not looking for evidence to support it.

June 7, 2011 7:23 pm

I believe in the context of this article, a hurricane might be considered as a ‘super-marine’ thunderstorm.

June 7, 2011 7:56 pm

it does not even require convection for water gas to rise

June 7, 2011 8:33 pm

RE: Willis Eschenbach
“For some time now I’ve been wondering what kind of new evidence I could come up with to add support to my Thunderstorm Thermostat hypothesis”
A ‘what if’ hypothesis is not a bad start if you do not go out of your way to ‘manufacture’ evidence to support it. In this case, I believe, it is necessary and sufficient to *prove* that there is a level in the upper atmosphere, such as the tropopause, that has an excess cooling ability allowing it to resist being heated or being pushed to a higher altitude by rising air from the surface. If this is not the case, then rising surface temperatures will be reflected directly in upper atmosphere temperatures. All rising air can do in the latter case is even out local hotspots without the ability to act as a general temperature regulation mechanism.
I do not believe that it is necessary to show that this temperature is ‘rock-solid’ in the face of surface temperature increases, only that the upper air temperature will not rise directly as the surface temperatures increase.

June 8, 2011 3:25 am

Try downloading a few months of these satellite photo animations
and watch the difference between the Pacific basin trade wind and prevailing westerlies wind patterns and how much different they are from patterns over the USA and the North Atlantic, that is due to mountain topography and lunar tides in the atmosphere.
The difference in the temperature climb rates are due to the dew point difference from cooler Eastern Pacific, lowering the specific heat index of the warmed parcel of air increases the temperature greater for the same joules of input, compared to the warmer and thus more humid air in the western takes more joules to get same amount of temperature rise.
The reason the three areas all have the same basic spread of temp gain is due to the additional moisture from evaporation needed to move the air upwards and pull in more surface air for the thermometer, is the same relative shift in dew point to effect the convection drive for that ambient temperature, at the uniform height of the gauges.
that magical point in mid day when the clouds start to form, is due to the convection meeting air at the height where the radiative pressure from the SST combined with the starting over night minimum dew point (that fell over night to match the SST), reaches the height where the aerobatic cooling lowers the condensational threshold past the dew point of the rising air parcel.
This explains the flat bottom base of clouds, the stronger the convective lifting the easier it is to break through CAPE that form at the top of the radiative limit of the energy from the surface temperature, on land soil moisture and the dew point minimum from the night before regulate this balance point. Over the ocean the SST is uniform and at the same latitude the thickness of the troposphere will be almost the same, hence the common reading of the total temperature shift. I would venture to say that you will see shifts in the spread with increases in latitude due to relative height of atmosphere lowers toward the poles.
This in no way disarms your hypothesis, just qualifies the changes predictable due to latitude changes of data base. Over the ocean if the air is warmer than the sea it will drop till the dew point of the surface air matches the SST (with maybe some adjustment for salinity, and its hygroscopic properties) that difference might be what you are seeing in the range of shift in min to max air temp, now that i think about it. Any time the dew point of the air tries to cool and drop below the dew condensational point, it condenses on the temp gauge and releases the heat of condensation giving that smooth bottom to the beginning of the 6:00am climb.

June 8, 2011 3:41 am

Willis Eschenbach says:
June 8, 2011 at 12:19 am
Richard Scott says:
June 7, 2011 at 5:38 pm
“For some time now I’ve been wondering what kind of new evidence I could come up with to add support to my Thunderstorm Thermostat hypothesis (q.v.). ”
Wrong, wrong, wrong! Searching for evidence to support your hypothesis is not the way science is done. That’s the kind of subjective nonsense we see from the alarmists.
Science is done by TESTING a hypothesis, not looking for evidence to support it.
Surely one of the ways of testing a hypothesis is to see if it is supported by experimental data … not sure what your point is here. I had a hypothesis. I looked at the observational data that applied (hourly ocean air temps), data that might or might not support my hypothesis. In this instance the data supported my hypothesis.
How on earth is that not science?
IF you look to see if there is a signal in the height of the sea tides due to the orbital parameters of the Earth Moon system, that is science, BUT If I take the patterns of the daily weather and compare that set of data against the same orbital parameters, that is judged to be Astrology and banned from further reading or consideration?WTF?
I get the same reasoning, that I am just picking data that fits the hypothesis, and they say correlation is not causation, even when it is predictive for the regulation of the atmospheric tides , just as it is for the sea tides.

June 8, 2011 4:20 am

Tom, what “sinusoidal shape” are you referring to? The shape of the temperature curves are not sinusoidal in the slightest, which is why I say it supports my hypothesis.
I am referring to the Fourrier transform of a periodic function with a period of 24 h (that’s what your T is) .
If you do that with a suitable origin of time (around sunrise) you will not be surprised that the first term of the Fourier development which is sin[(2.Pi/24).t] (yes, a sinus !) has the by far biggest coefficient.
That is what I meant by saying that the SST has a “sinusoidal shape”.
Everything else, as I already explained in my first comment are just corrections due to harmonics at higher orders.
This curve (SST) is so strongly sinusoidal that the corrections are relatively small.
If you have a Fourier transform software, just feed in it the coordinates of the curves you have and you will see how far you were from the truth when you thought that the shape “was not sinusoidal in the slightest” .
I stress one more time that I have no criticism against your qualitative description of what’s happening with SST in the tropics AT A 24H SCALE.
I am sure that it’s indeed what happens .
And I just wrote some simple equations which are a quantitative equivalent of your qualitative description .
If you wanted you could get a very good fit for the day part with this model. The night fit would be good too but not exceptional because the backradiation of the clouds during the first night hours is neglected . But one can easily add it if one wants to .
Btw it’s true that there are “only” 2 degrees of freedom . However once you realize that one of the degrees of freedom is a function (the cloud cover – a(t)) , it is in fact equivalent to have an infinity of degrees of freedom 🙂
That’s why I don’t need to do the computer work to know that the fit of the model to the curves (temperatures not anomalies !) would be almost perfect for the day half .
And I wouldn’t do it anyway because as I said , I can’t see what’s new or interesting in there.

Tom in Florida
June 8, 2011 5:09 am

Willis Eschenbach says:
June 7, 2011 at 2:04 pm
“Actually that part is pretty well understood. See CAPE. However, that just shows the conditions of instability and will give an approximate time for cumulus or thunderstorm formation. It doesn’t specify the spatiotemporal distribution of the storms … a fancy way of saying we can say approximately what time of day the storms are likely to start, but we can only give probabilities about the wetness of your golf outfit …”
Thanks for the CAPE link. While I was being somewhat tongue in cheek about the golf, thunderstorms are a serious threat to golfers because of lightning. Most golfers I know are pretty keen about weather conditions during our hot months and understand the consequences of ignorance. As I once wrote on a golf web site I had,
“There is no penalty for heading to the clubhouse when lightning is around. The beer tastes much better when you are alive.”
Now, if you can just predict over which course those thunderstorms are going to pop up ……….

June 8, 2011 8:43 am

Many thanks for your courteous reply. I have just tried again for 10 mins to get my heat gun to make any change to temperature of the water in the bucket.No joy. I am applying serious heat here. If I can’t make any impression with a heat gun what chance does a molecule of co2 stand.Science appears to me to have completely underestimated the strength of surface tension or maybe nobody thought of it. If I’m right the whole agw thing is toast. Give it a try. kind rgds r.m.b

Theo Goodwin
June 8, 2011 9:23 am

Richard Holle says:
June 8, 2011 at 3:41 am
“Wrong, wrong, wrong! Searching for evidence to support your hypothesis is not the way science is done. That’s the kind of subjective nonsense we see from the alarmists. Science is done by TESTING a hypothesis, not looking for evidence to support it.”
You do not know what your hypothesis states (implies) until you know all the evidence that it implies. So, looking for empirical evidence is just a matter of fleshing out the hypothesis. And, as you find true predictions from the hypothesis, you build a record of confirmation. Of course, if you discover predictions that are false then you have most likely found that the hypothesis has been falsified.
I think you are working with a rather simplified version of Popper’s thesis that hypotheses should be bold and that scientists should attempt to falsify them. Good suggestions, but to ignore the evidence is to stunt your understanding of the hypothesis. Popper was a very good thinker in the area of hypothesis testing and such but his work is not up to the level of that of Carl G Hempel, Israel Scheffler, Isaac Levi, and some others. Scheffler’s “Anatomy of Inquiry” discusses Popper in detail.

Septic Matthew
June 8, 2011 11:19 am

steven mosher says:
June 7, 2011 at 10:53 am
“2. The thermostat [hasn’t] keep the planet from warming. that is, unless it changes the way heat eventually returns to space (radiation), then it’s not really doing anything interesting on a global scale.”
I think that your conclusion is too strong. The observed warming undercuts Willis’ analogy to a “thermostat”, but leaves open the possibility that the mechanism he describes might be a net negative feedback to CO2-induced global temperature increase. He has not elaborated all the mechanisms (I expect he’s working on it), but the mechanism by which increased CO2 and increased temp cause increased heat transport to above cloud level should reduce what’s called the “climate sensitivity” even if the basic mechanism of CO2-induced warming is correct.
In general the AGW theory depends too much on globally and temporally averaged temperatures, and not enough on the careful examination of particular heat transfer mechanisms at particular times, temperatures, and places. The mechanism that Willis explores here corrects that defect, to a small degree at least. Careful measurement and mathematical analysis are required, but the mechanism that Willis has been addressing opens up the possibility that, starting with temperatures as they are now, future CO2 increases and associated low level temp increases will produce no future net heating, and even that the last 150 years of temp increases have been independent of CO2 all along.
I wrote “to a small degree at least”, but the heat flows in the mechanism are considerable, and could represent sufficient heat transfer to completely counteract the hypothesized H2O feedback that boosts the estimated CO2 sensitivity from about 0.6C (by some estimates) to 3.5C (the warmers’ favorite). More work is needed, I repeat, but the mechanism that Willis is addressing is really interesting.
to Willis I say,
thanks, and keep up the good work.

June 8, 2011 3:32 pm

Willis, I would still like to know your thoughts on the Lindzen & Rondanelli paper I referenced above, in case you missed my comment. Thanks!

June 8, 2011 9:40 pm

“I suspect the difference is that the Guam station is on an island 110 metres above the ocean, and the information from Zeng et al. is buoy data from a couple metres above the ocean. I’ve checked the Zeng figures against the TAO/TRITON buoy data and they agree.”
Fascinating! I had no idea that the durnal variation was so small over water (but I should have). Thanks.

Gary Palmgren
June 16, 2011 6:48 pm

I had to ponder this for a week. I like the thermostat hypothesis. If true then this would show how the recent tornado outbreak is related to climate change. Your hypothesis says that the tropics will try to maintain the same temperature regardless of other forcing such as solar changes. If the net energy in the globe increases then this will show up as increased polar warming as the tropics will not warm due to increased thunderstorms. The temperature gradient from the equator to the poles will be reduced so there will be less turbulent motion in the temperate zones and milder weather. Thus the warmists, shouting more extreme warmcold and wetdry have it exactly wrong. Global warming leads to less violent and extreme weather.
Conversely, a drop in global energy will result in a greater temperature gradient as mostly the poles cool and more violent weather will occur as the turbulence seen in the frontal storm systems increase. Thus, the quiet suggestion that the recent tornado outbreak is due to cooling becomes evidence for the thermostat hypothesis. I do not for a moment believe Hansen’s single urbanized thermometer is telling us what is happening at the North pole. It has to be getting colder.
This is scary. More turbulent frontal storms will result in shorter growing seasons as cold weather storm systems will end the growing season with early frosts even if the local average temperature does not drop that much. A week a warmer weather after a hard killing frost does not help the growing season even though the average monthly temperature may not show much of anything. I have always thought a measurement of the growing season would be a lot more useful than meaningless average of the intrinsic temperature variable.

June 23, 2011 6:26 am

RE: Gary Palmgren: (June 16, 2011 at 6:48 pm)
I had to ponder this for a week. I like the thermostat hypothesis. If true then this would show how the recent tornado outbreak is related to climate change. Your hypothesis says that the tropics will try to maintain the same temperature regardless of other forcing such as solar changes.
This disregards the fact that the severe tornado activity this year is due to more cold air with a lower thermostat setting sliding south over warmer air. The reason this activity peaks out in the spring is because the tropics and northern subtropics are rapidly warming from direct overhead sunshine while the arctic is still very cold from the winter.
It may help to consider how this proposed temperature control mechanism may work. Note that the CO2 concentration is largely a side issue. At the tropopause the CO2 band is not as wide as at ground level but it is still saturated and one can assume that most CO2 emissions will be at those same wavelengths where it is also most absorptive.
I think that the thickness of the troposphere is probably related to the *absolute* humidity at ground level. In the troposphere, a normal atmosphere has a lapse rate of 6.5 degrees C colder per kilometer increase in altitude. There may be discontinuities in this slope where the air aloft is from a different source from the ground level. When a warm parcel of dry air rises, it cools adiabatically (without energy exchange) at a rate of 9.8 degrees C per kilometer increase in altitude so that it will quickly reach an altitude where it is as cold and as dense as the surrounding air and thus come to a stop.
If that air is damp, however, it may rise to an altitude where condensation begins. Once this happens, the latent heat of vaporization reduces the cooling rate to 5 degrees C per kilometer increase of altitude. When this happens, the rising air parcel is actually getting warmer than the surrounding air at a nominal rate of 1.5 degrees C per kilometer increase in altitude. This is the positive-feedback engine that can cause this parcel of air to rise to the top of the troposphere. In the tropics, where the tropopause altitude is some 17 kilometers, we might expect this air parcel to be over 24 degrees C warmer than the surrounding air if the 6.5 degree C per kilometer lapse rate and 5 degree C per kilometer wet cooling rate continued almost up to that level. Perhaps the tropopause may be thought of as the ‘dry-out’ altitude.
It would seem that this process would be most effective at regulating oceanic temperatures as condensation would tend to begin at relatively low altitudes.

June 29, 2011 7:08 pm

Please see Curry’s
Critique of the HADSST3 uncertainty analysis, especially the shift in wartime sampling from every 6 hours to 8 AM, Noon & 8 PM. See:
Reassessing biases and other uncertainties in sea-surface temperature observations measured in situ since 1850, part 2:
biases and homogenisation
Journal of Geophysical Research
From eyeball guestimates of your diurnal temperature variations this wartime change in sampling time appears to give a substantial wartime sampling time Type B (bias) error of 0.17 deg C or 0.09 C.
Look forward to your quantitative evaluation of this time sampling bias error.

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