Air Conditioning Nairobi, Refrigerating The Planet

Guest Post by Willis Eschenbach

I’ve mentioned before that a thunderstorm functions as a natural refrigeration system. I’d like to explain in a bit more detail what I mean by that. However, let me start by explaining my credentials as regards my knowledge of refrigeration.

The simplest explanation of my refrigeration credentials is that I have none at all. As with many trades I’ve pursued, I have no training in refrigeration. But the challenge was simple. When I was 37, a good friend of mine and I had taken the job of installing a blast freezer system in a 60′ (18m) steel sailboat in Fiji called the Askoy. I was sure we could do it … despite the fact that at that point in my life, neither of us had ever taken apart a refrigerator, or could even explain how a refrigerator worked.

How the heck do I get things coldFigure 1. The Challenge SOURCE

But we had two months before the job started, and one rule of thumb has never failed me—Do Your Homework

I was laughing about this with my friend this afternoon. We’ve been partners in various oceanic ventures and adventures over the last forty years. He reminded me that I’d bought my refrigeration gauges and my freon sniffer at the local flea market, I’d forgotten that detail. He was to do the metalwork, the piping and the soldering and such, while I had to design the system and charge it and get it working. We discussed our ignorance at the time, and he said “I never had any doubt that you’d do the refrigeration part.” I laughed and said “I never had any doubt that you’d do the metalwork part.”

I learned refrigeration the old-fashioned way. I taught myself.

WARNING—this post is a 50/50 mixture of science and autobiography, call it autosciography. If that makes your brain explode, DO NOT continue reading.

I went to a technical bookstore in San Francisco and bought a college refrigeration textbook, and a refrigeration technicians textbook. I started with the college refrigeration text, just like I was in college again. I read every word of every chapter, and then I answered all of the questions at the end of each chapter. I went back on the ones I missed until I understood them as well. At the end of the first month I could knowledgeably discuss superheat and the difference between the kinds of Freons and how different types of refrigeration systems worked and what the units called “tons” measure in refrigeration (the cooling power equivalent to the melting of 2,000 pounds of ice starting at 0°C in 24 hours).

Then once I understood the theory backwards and forwards, I got out my refrigeration gauges and my sniffer, and I found some old refrigeration systems and I started working through the refrigeration technicians manual. By the end of the second month I could test and charge and repair a system, fine tune the setup, discharge the system and recapture the freon, tear it down and build it again, whatever you wanted. I was ready to go.

So that’s how I learned about refrigeration, and my friend did the same regarding the metalworking and silver soldering and all the rest of the knowledge he needed. And after we finished the installation of the blast freezer, I subsequently made good money at various times diagnosing and repairing marine refrigeration systems. I’ll return to the question of my credentials and the lack thereof in a bit. But first, for those who like me couldn’t explain how a refrigeration system works, here’s my explanation.

A refrigerator cools things in exactly the same way that sweating cools your body—by evaporation. Of course instead of using water like your body does, a refrigerator uses freon, or one of the modern refrigerants. But the principle is exactly the same regardless of the “working fluid”. You use an evaporating liquid to remove the heat from whatever you want to cool down.

Now, if the working fluid is actually boiling, you get the maximum evaporation. So for a particular refrigeration application, you might pick a liquid (one of the various Freons in the old days, now other liquids) that boils at say ten degrees below freezing.

Of course, your body uses up the water that cools us when we sweat. We don’t try to recapture that water, it condenses somewhere else.

But we don’t want to waste valuable freon. We’d rather condense it back to a liquid. One way to do that, of course, is to pipe the vapor to some cold place, where it naturally condenses back into a liquid. In The Inventions of Daedalus, the eponymous author propounds another of his crack-brained but plausible schemes, this one for air conditioning Nairobi by running the vapor up to the top of Kilimanjaro, where it would condense and run back down by gravity. Here’s my sketch of his plan:

nairobi airconditioningFigure 2. Daedalus’s plan for air-conditioning Nairobi (click to expand). The working fluid boils at say 5°C (41°F). The liquid return pipe is insulated so the fluid doesn’t boil on the return path to the evaporator.

The working fluid boils in the evaporator on the lower left. The evaporator is like a car radiator, and a fan blows through it, and the resulting cool air is used to air condition Nairobi.

The vapor then moves up to the top of Kilimanjaro, where a condenser (also looks like a car radiator) has icy natural winds blowing through it to condense the liquid. This liquid then flows by gravity down an insulated tube and back to Nairobi to start the cycle again. And like most of Daedalus’s inventions, there’s no reason you couldn’t actually build that.

Now, that’s the basic principle underlying how a refrigeration system works. A liquid turns to a vapor, absorbing heat in the process. This is called “latent heat”, because it doesn’t increase the temperature.

That vapor, containing the latent heat, is piped away from the object you want to refrigerate. Then somewhere else, it’s condensed back to a liquid, and in the process releasing the latent heat as sensible heat. Finally, the liquid is returned to the original location, to repeat the cycle.

Note the importance of the two phase changes in the process—evaporation (picking up latent heat) and condensation (releasing that latent heat elsewhere as sensible heat). Those two processes, evaporation and condensation, are the central part of the whole process of refrigeration. It’s just a very efficient way to move heat from A to B.

Now, consider Figure 3, which shows what a tropical thunderstorm is doing, and how it functions as a refrigeration system.

Down at the surface, the water is evaporating and refrigerating the surface. The thunderstorm forms over a local hot spot. The evaporation cools the surface, and the energy is transferred to the air as latent heat. The hot, moisture-laden air moves upwards.

Up above the “lifting condensation level”, the elevation of the base of the clouds where condensation begins, the water condenses into larger and larger droplets. The latent heat is released back into the air as sensible heat. The water then falls as rain, to complete the cycle.

thunderstorm refrigeratorFigure 3. Natural refrigeration system. Just as in a domestic refrigerator, a working fluid (in this case water) is evaporated to remove heat from the surface, the area to be refrigerated. After rising up into the thunderstorm, the water is condensed, releasing the latent heat as sensible heat.

As you can see, this is the same system that Daedalus proposes to air condition Nairobi. It uses the same principle as your home refrigerator. Evaporation cools what you want cooled, and somewhere else, you condense the working fluid and get rid of the heat.

Now, let me start by making one thing crystal clear.

THIS IS NOT A FEEDBACK!!!

Instead, it is a natural refrigeration system, capable of cooling the surface well below its starting temperature. Treating it mathematically as a feedback is a huge mistake. It is nothing of the sort. It is a threshold-based emergent phenomenon which actively refrigerates the surface.

[UPDATE: In the comments, people have been confused by this question of feedbacks, obviously I was not clear enough. When I say it is not a feedback, I mean it is not a simple linear feedback of the only kind considered by the IPCC. Instead, it is a control system which utilizes feedbacks of a host of kinds to maintain a constant temperature. -w.]

Not only that, but it selectively refrigerates the hot spots, forming just where it is needed. As a result, it is very difficult to represent by averages. This is especially true because its response time is minutes to hours, not days. The hot spot doesn’t really have time to get going before it is refrigerated into submission.

It gets better, much better. You see, up until now, I’ve just described the parts of the system that correspond exactly to manmade refrigeration systems. Let me point to some very clever wrinkles that thunderstorms use to increase their refrigeration capacities and to cool the surface more efficiently and more widely.

• Wind

The thunderstorm generates wind at its base, and evaporation is proportional to wind speed. If the wind underneath the storm cloud increases from say 5 knots to 20 knots, or say from 2 m/sec to 8 m/sec, evaporation goes up by a factor of 20 / 5 = four-fold. In other words, the self-generated wind alone multiplies the strength of the refrigeration by about four.

In addition, the wind increases the evaporative area by blowing water into the air as spray and fine droplets. These have a large surface area and evaporate rapidly. This also increases the strength of the refrigeration.

• Dual fuel

Thunderstorms run on both temperature and moisture. Moist air is lighter than dry air. The four-fold increase in evaporation yields a proportional increase in the vertical speed of the air moving through the thunderstorm, because it is much lighter. It also keeps the thunderstorm from dying out if the temperature drops, because once the wind starts, the moist air is light enough to keep the thunderstorm going to well below the temperature required for initiation.

• Direct surface refrigeration by cold working fluid.

In most manmade refrigerators, evaporation is the only mechanism for cooling the objects to be refrigerated. The working fluid is not used directly to cool down what is being refrigerated. Instead, it’s brought to the evaporator in an insulated tube and immediately evaporated to carry away the heat.

But in addition to the evaporation, a thunderstorm also delivers large quantities of chilled water directly to the surface. This is a separate and distinct refrigeration mechanism, one not generally utilized in manmade refrigerators.

• Refrigeration via entrained wind.

You’d expect that the rain would warm as it fell through the warmer lower atmosphere, and to some extent it does. But it also entrains the air around it as it is falling, carrying it along. This sets up a vertical entrained wind that falls right along with the rain. That wind is constantly cooled as it falls by the evaporation of the rain that it is mixed in with. And since the rain and the chilled air fall together as a package from aloft, they both arrive at the surface much cooler than the surroundings. Often when standing out on the apartment deck in the Solomon Islands at night, the first sign of the approach of a thunderstorm would be the arrival of the cool entrained wind.

The entrained wind falls vertically with the rain, but unlike the rain it’s not absorbed by the surface. So it blows out cold air horizontally in all directions from the base of the rainfall. This blast of cool air is quite distinct. It smells of the upper atmosphere where it originated, and it is very refreshing on a hot night. It is also a separate and distinct refrigeration mechanism.

• Re-use of heat of condensation.

This one is sometimes done in manmade installations. In the thunderstorm, the heat is used to drive and sustain the building of the “tower”, the tall vertical part of the cumulonimbus cloud. This in turn increases the speed of the upward flow through the core of the thunderstorm, and allows for the possibility of another phase change.

• Additional phase change

It would certainly be possible for humans to design a system using a second phase change in the working fluid. Right now, our refrigeration systems utilize the phase change from gas to liquid and back again. But there’s another possibility, to go from gas to liquid to solid and back again.

The advantage is that you can move more heat that way. Instead of just the heat from one phase change, you could move the heat from two phase changes as latent heat.

So why don’t humans utilize both phase changes for extra efficiency? Well, we haven’t figured out an easy way to get the solid working fluid from wherever it was frozen, back to the evaporator to start the story over. I mean, we could freeze the Freon after it’s condensed into a liquid … but then how do we move solid Freon back to the evaporator to continue the cycle? With wheelbarrows?

Nature doesn’t mind these small problems, however. Nature continues to cool the water past the point where it condenses, and all the way to where it freezes … and then it uses gravity to return the solid working fluid back to the surface as ice. I can only bow my head in awe, what a clever setup. At the surface the ice will first melt (cooling the surface) and then warm up to the local temperature (further cooling the surface) and then evaporate to continue the cycle.

• Inter-storm coupling.

When the need for surface refrigeration gets high (anomalously warm surface temperatures), a new emergent pattern appears. The thunderstorms start to align themselves in long rows, called “squall lines”. These in turn have long canyons of descending air between them. This is a type of Rayleigh-Bénard circulation that greatly increases the throughput, and thus the refrigeration capacity, of the mass of thunderstorms.

CONCLUSIONS

• At all times and all around the planet, thunderstorms are constantly refrigerating tropical hot spots to prevent the globe from overheating. This constant refrigeration is what controls the surface temperature of the planet, not CO2. If this refrigeration system failed even for a week, we’d fry.

• The thunderstorm refrigeration system utilizes the same familiar principles of manmade refrigeration—evaporation removes the heat from what you want to refrigerate, and condensation gets rid of the heat somewhere else.

• In addition, the thunderstorm refrigeration system utilizes some unfamiliar processes, all of which combine to greatly increase the refrigeration capacity of a given thunderstorm.

• The refrigeration is selective, responding to local temperature—the hot spots get refrigerated until they confess, and the cold spots get nothing.

• The current generation of climate models deal with feedbacks. This is nothing of the sort. It is an emergent mobile self-sustaining refrigeration system, not a feedback of any kind. It needs to be analyzed as such, and it is very difficult to do so by means of parameters or averages.

• The system responds to temperature. It is not driven by the forcing, nor does it respond to areas of high forcing. Instead, it actively responds to surface temperatures. The formation of a local hot spot is quickly followed by the formation of a corresponding refrigeration system to cool the hot spot down.

• The system is extremely sensitive to the formation of local hot spots. It puts a refrigeration unit right to work on the problem. On the other hand, it is indifferent as to the cause of the hot spot. It chills them all the same.

• In addition, the surface temperature of the system is relatively insensitive to the number of hot spots—you just get more or less refrigerators to match the number of hot spots, and that keeps the temperatures within bounds. And this in turn means that the surface temperature of the system is relatively insensitive to the forcing.

• As a result, the system doesn’t care about CO2, or about small variations in the sun, or about the effect of volcanoes. The threshold for refrigerator formation is based on surface temperature, not on CO2. If there are more hot spots, the system simply makes more refrigerators, whether the hot spots are from CO2 or from a clearing of the aerosols or from a 5% increase in sun strength over a billion years.

• In such a system, the idea of “climate sensitivity” doesn’t go anywhere or mean anything. The system is relatively insensitive to the forcing, not sensitive. The system responds to hot spots by building refrigerators … and as a result the surface temperature is maintained despite variations in the forcing. The problem is not that the relationship is non-linear. In a thermostatically governed system such as the climate there often may be no relation all between forcing and temperature.

• This is a relatively simplified (but very accurate) explanation only one of a host of interlocking emergent phenomena that maintain the surface temperature within ± half a degree in a hundred years. Yes, there are lots of details I’ve left out, and manmade refrigeration systems have other valves, bells and whistles … if you’re interested lets discuss them, but please don’t bust me for leaving them out.

========================

That’s what I wanted to say about refrigerators and thunderstorms. When you are analyzing our climate, which contains powerful emergent refrigeration systems like thunderstorms, you can’t analyze them as a feedback. It’s very difficult to parameterize them. You have to get out your refrigeration tables and analyze them as what they are, huge natural refrigeration units, and very efficient ones at that.  My takeaway message is this:

The surface temperature of our amazing planet is set and maintained by the constant refrigeration of the surface hot spots as they form, not by the forcing, whether from CO2 or anything else. 

========================

To close, earlier I said I’d return to the question of my credentials for talking about refrigeration. Well, before we went to Fiji my friend and I researched the available marine refrigeration systems. We went and talked to the people freezing the product and saw what they used. Harlow, the owner of the boat, wanted to be able to purchase and process what they call “crayfish”, the tropical ocean lobster. To do that, you want to flash-freeze them with a wind colder than 40° below zero or so (either -40°C or -40°F, they’re the same). They need to be snap-frozen, an ordinary freezer won’t do it.

So my friend and I located a killer packaged refrigeration unit, all assembled, self-contained, ready to go. We could bolt it in and go processing in a couple weeks, because that was the dream. We’d finish the freezer and go processing crayfish around the tropical South Pacific … what’s not to like? So we went down to Fiji. Harlow was going to buy the packaged unit and bring it down.

But Harlow decided he knew better. So he shows up in Fiji with a refrigeration compressor, and an evaporator, and a condenser, and some fittings and valves and pipe, and tells us he wants it built from scratch. Oh, and he wants it water-cooled, not air-cooled. Oh, and not driven electrically, but run off a “lay-shaft”, a separate shaft driven by the main engine which drives other machinery in turn.

Ooooooh kaaaaay … we can do that, Harlow, but it’s gonna take a while.

So for our very first refrigeration project, my friend and I got to design and build an entire marine engine-driven commercial-type blast freezer system with a water-cooled condenser … from scratch, from the individual pieces. Might as well set the bar high, I figure …

So I got out my texts and tables and designed it up, and we got started, nothing else to do. We built the lay-shaft, and installed the refrigeration piping from the engine room up forward to the freezer room, belt-drove the lay-shaft off the main engine, and then got the water pump and the refrigeration compressor to run off the lay-shaft, and laid out and cut and soldered and tested all of the piping, and that’s only a tiny fraction of all of the tasks … in a foreign country, with not a whole lot of refrigeration parts available, and no instruction manual.

Like we warned Harlow, it took a while, just about six months to do it, with my gorgeous ex-fiancee serving as the ship’s cook and nurse and general hard worker. But finally, after scraping Suva dry of various refrigeration parts and pieces, one fine day I charged up the system, and we gave it the first test … and the wind off of that blast freezer was at -50°F (-46C) just like we planned. Indeed, the blast freezer worked like a champ. As long as the main engine was on it could be clutched in or out to run it, and the lay-shaft could also be driven by the auxiliary engine to keep the freezer hold and the seafood frozen if the main engine died. It was a sweet rig.

So naturally, Harlow decided that we should have a party to celebrate, and we were all up for the plan. We’d been anchored right offshore from the Royal Suva Yacht Club the whole time, so we invited everyone.

There was a trimaran owned by a friend at the Yacht Club at the time, so we tied her up alongside the Askoy. That was for the big wide stable dance floor, we hung speakers from the rigging on each side. My friend Doc Lowry used his 28′ open skiff as the shore boat, to bring out loads and loads of people from the Yacht Club dock. He spent most of the night moving folks from the Club to the party and back again … then out to the party again …

As each person arrived, we took them a couple at a time down into the blast freezer. You entered through a hatch in the deck, and down below it was cold, cold, cold. I had put a number of bottles of vodka into a basket right in front of the blast of the freezer. I stuck a thermometer through the cap in one of them, it registered minus forty degrees … I still have a picture of it around here somewhere. [UPDATE—found the picture. You can see the red indication at minus forty]

askoy freezer party

So as each person came down into the freezer, we’d prop them up in front of the wintry blast. The wind was strong, and blowing at minus fifty degrees F. Most of these folks were Fijians, who had never seen any place that was as cold as plus 50°F (10°C), much less minus 50°F. They started shivering as soon as they got inside, they’d never in their lives felt a wind at minus fifty. So I or their other host of the moment would pour each person a reasonable glass of pure vodka at minus forty degrees.

Vodka at that temperature hardly has any taste, and the folks were in a hurry to get out of that damned freezing cold, so they’d drink it down straight like it was water … then we’d take them back out into the balmy tropical night. They’d get about ten steps across the Askoy deck, maybe somebody would pull them onto the dance floor, maybe not, but in either case, a few steps later, the combination of the initial freezing cold wind, the vodka, and the subsequent heat would make their knees wobbly and their eyeballs jiggle, and the Askoy Freezer Party got just that much merrier. The Yacht Club Bar eventually closed, and the bar guys and the Club office ladies joined the party. People kept arriving. Big Jenny showed up at three AM and shouted “Am I late?”

“No, party just starting, girl!” We took her into the freezer and gave her a double shot, and indeed the party restarted when she came back out.

I’ve not been to too many parties like that one. Rumor had it that it resulted in one marriage and a couple of divorces. Both a wallet and a set of eyeglasses committed suicide by jumping into the Suva Harbour sometime during the night.The amount of debris on the deck and the dance floor was overwhelming. And me, I proved it was a magical party. By the end of the night I was so drunk that shortly before dawn I went to sleep on a nice, soft pile of rope I’d discovered up front near the bow of the boat. It was covered by some gunny sacks, and I nestled in and got comfortable and was gone.

When I woke up, though, I sadly concluded that some ungrateful bastard must’ve replaced the rope while I was sleeping, because I found I was nestled on the usual pile of Askoy anchor chain … in its usual spot up in the bow … covered up as always with dirty gunny sacks …

Sleeping on chain, I found out, makes a man say very bad words upon awakening. If you are given an alternative mattress choice, say a bed of nails, or a small barnyard stall with two chickens and a rabid goat, I’d advise taking it. Plus it seemed that the entire Fijian mosquito tribe had taken advantage of the party to do some in-flight refueling. My body was royally whupped in the morning, big anchor chain marks and dents in my hips and side, covered in mosquito bites.

But I didn’t care a bit. The freezer was done, the icy blast off the evaporator was at minus fifty, the vodka had been at minus forty all night long, the party was a success, and my gorgeous ex-fiancée and I had danced away the night.

And that’s all there is to my refrigeration credentials.

Regards to everyone,

w.

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Lance Wallace

I guess the ex-fiancee found a nice warm comfortable bed somewhere and left you to your gunny sacks and anchor chain. Some kind of lesson here about practical-minded females and romantic but goofy males.

Leonard Weinstein

Willis,
I enjoyed most of your story (as I enjoy your other ones). There is one issue. The air temperature is colder at higher altitudes (on average) due to the lapse rate. However, when the air circulation carries this air down, it warms up due to adiabatic compression at lower altitude, and does not supply colder air to the surface. That is not part of the cooling effect. The cooling from evaporation, dropping of colder drops (which do not heat due to adiabatic compression), and the fact that wind increases surface evaporation and cools your body (removing sweat faster) are the total effect.

JoeJ

Cool!

I think they give Pulitizers for stuff like newspaper stories. Why not an internet award? That’s actually an interesting idea. If fact I predict [without benefit of models] there will be a Pulitizer for something on the internet within the next ten years.

Having recently sold and retired from the HVAC business, I can now understand refrigeration.
BTW, I’m sure you’ll be the one to leave the 1,000,000th reply. LOL
Thanks w.

OldWeirdHarold

Funny you mention refrigeration. I had to replace some R-12 in my car’s AC a while back. The stuff is illegal to make in the US, but not to buy. But you have to have an EPA certificate to be able to buy it. So I went online and took some Mickey Mouse course, and paid $15 and took the test (this was probably about 10 years ago), and now I have an EPA refrigeration mechanic certificate thingy good forever. Never did get around to the AC project.

Marvellous yet again, Willis. Since reading your writings about clouds, I find I look at them differently. I’m learning quite a lot in here, and having a blinking good read while I’m at it. Thank you so much.
Cheers. 🙂

Bob

Willis, did you ever have the opportunity to use a sling psychrometer while at sea? I had one years ago and unfortunately sold it. I’d use it to describe to my children why evaporation cools. Kinetic energy is directly proportional to absolute temperature – so as water molecules leave the surface of skin, kinetic energy decreases, and so does temperature.

In such a system, the idea of “climate sensitivity” doesn’t go anywhere or mean anything. The system is relatively insensitive to the forcing, not sensitive.

Insensitivity IS a sensitivity. It is a sensitivity of zero (in the case of complete insensitivity, or complete transport away of any hotspot hotter than the thermostatically controlled level). This sensitivity of zero also corresponds, by definition, to a particular feedback (a feedback of negative one, or completely offsetting). Thus it seems quixotic for Willis to deny that the thermostatic mechanism he describes can be viewed in terms of sensitivity and feedback. It has strong implications for sensitivity and feedback.
There may be good reasons to dislike the forcing-feedback straightjacket that the IPCC has imposed (pursuant to its stated and highly-biased objective of analyzing the human impacts on climate), but the fact is that this formulation HAS been imposed and is the language of 95% of climate science. For Willis to eschew this language when his own formulations actually have strong implications for feedbacks and sensitivities is to muffle his own voice.
Noting the flaws in the forcing-feedback framework does not require denying the implications of one’s own ideas for analyses done within this framework.

Ian Cooper

Willis, would it be fair to say that if tropical thunderstorms can act as refrigeration units at their scale then a full blown tropical cyclone could have a similar effect but on a larger scale? I ask this because I have evidence of such a thing happening here in New Zealand in 1968. I was graphing T-Max data for the austral summer of 1967-68, a brilliant summer that came to a sudden holt with the arrival of TC Giselle, the infamous storm that took out the inter-island ferry Wahine at the mouth of Wellington Harbour on April 10th that year. The ferocious winds that lashed the Cook Strait area that terrible morning had caught everyone by surprise. Forecasters had thought that in typical fashion the storm would lose a lot of its strength once it crossed land. This was pre-satellite and dopler radar days so the unexpected increase in ferocity was unseen in the night.
The main thing that showed up in the T-Max data for my home town some 90 miles north of Wellington was the staggering drop of around 8 degrees C that ensued directly after the passing of Giselle. The memorable heat of the that lingering late summer-early autumn was gone and never returned. A massive step change had occurred in a way that I haven’t seen in subsequent transits of tropical cyclone remnants (they are hardly ever still officially T.C’s when they make landfall in N.Z.) over New Zealand. A few have had a short term affect before temperatures have rebounded, but Giselle was agame changer for sure.
Cheers
Coops

Willis. After all these years, you have dashed my belief that refrigeration was a product of black magic. If you yearn to visit Gualala, and eventually everyone does, drop in on a second or fourth Tuesday. I and the rest of the Lions would love to hear some of your tales.

Willis,
It’s certainly true that hurricanes can cool the surface. I made some animations here of high resolution daily SST in the N Atlantic with hurricane tracks superimposed. Although the resolution sounds good, hurricanes can move a long way in a day. Still, some do leave very marked cooling tracks.
Of course, they have to cool something – they are heat engines and transferring heat from warm to cold is where their energy comes from.

Mike Wryley

Willis,
Since you mentioned silver soldering and clorofluorocarbons in nearly the same breath, and because many who tread this site may not be as well read, crafty and lucky as you but never the less inspired to follow in your sandal tracks, I feel it might be worth mentioning that open flames and Freon are a deadly combination.

ed mister jones

I understand T-Storms, as I fly around them. I understand the transport of heat from the surface and near surface hot spot. I understand the cooling effect. But the Heat does wind up somewhere, and if that somewhere doesn’t pass the heat somewhere else yet again, then the first somewhere is going to get warmer (as happens when you run an ordinary refrigerator in an unventilated room). . . . So the next piece might I suggest, should deal with the “and then . . .” aspect of the voyage of the heat from the Hot Spot to it’s next destination(s)?
Do we know the effect of the dissimilar temperature water on the Ocean’s vertical circulations as you discussed previously? Can it be quantified? (rhetorical).
So many moving parts and variables, the Idea that ‘they’ have enough knowledge to model it and predict outcomes Decades into the future is laughable.

I tried freezing vodka with a big block of dry ice once, same effect on a warm night – people don’t realise how drunk they are. But not nearly as much fun as a blast freezer!

Willis Eschenbach

Alec Rawls says:
March 11, 2013 at 8:45 pm

In such a system, the idea of “climate sensitivity” doesn’t go anywhere or mean anything. The system is relatively insensitive to the forcing, not sensitive.

Insensitivity IS a sensitivity. It is a sensitivity of zero (in the case of complete insensitivity, or complete transport away of any hotspot hotter than the thermostatically controlled level). This sensitivity of zero also corresponds, by definition, to a particular feedback (a feedback of negative one, or completely offsetting). Thus it seems quixotic for Willis to deny that the thermostatic mechanism he describes can be viewed in terms of sensitivity and feedback. It has strong implications for sensitivity and feedback.

Thanks, Alec. You can also define the sensitivity of temperature to women’s hemlines as zero … but as I said above, that doesn’t go anywhere.

There may be good reasons to dislike the forcing-feedback straightjacket that the IPCC has imposed (pursuant to its stated and highly-biased objective of analyzing the human impacts on climate), but the fact is that this formulation HAS been imposed and is the language of 95% of climate science. For Willis to eschew this language when his own formulations actually have strong implications for feedbacks and sensitivities is to muffle his own voice.

My problem with discussing this as a feedback is that there is a huge difference between a feedback and a governor. I’ve been writing a post on this, I should go back and finish it. It is a very important distinction.
A governor USES directed, measured feedback to achieve homeostasis … but that doesn’t mean that a governor IS a feedback. It is not, and trying to analyze a governed system as though it only contained simple linear feedback of the IPCC variety is a recipe for disaster … or for a climate model.

Noting the flaws in the forcing-feedback framework does not require denying the implications of one’s own ideas for analyses done within this framework.

The main problem is that the “forcing-feedback” paradigm doesn’t contain a governor, so yes, I do have to deny that their framework is sufficient to encompass the climate. This is why I describe myself as a climate heretic rather than a climate skeptic—I think that the underlying paradigm is totally incorrect.
Part of the problem is that climate sensitivity is not a constant. Instead it is a function of temperature and other variables. As such, treating it as a constant only gives wrong answers.
Regards,
w.

Isn’t “Reversing Climate Change” the same as “Manufacturing Climate Change”, thus returning the Climate to a previous state? And what would that state of Climate Be?

Willis Eschenbach

ed mister jones says:
March 11, 2013 at 9:45 pm

I understand T-Storms, as I fly around them. I understand the transport of heat from the surface and near surface hot spot. I understand the cooling effect. But the Heat does wind up somewhere, and if that somewhere doesn’t pass the heat somewhere else yet again, then the first somewhere is going to get warmer (as happens when you run an ordinary refrigerator in an unventilated room). . . . So the next piece might I suggest, should deal with the “and then . . .” aspect of the voyage of the heat from the Hot Spot to it’s next destination(s)?

Thanks, Ed, you are correct. As you point out, refrigerators don’t vanish the heat. Regarding thunderstorms, they move it aloft as latent heat. When the water condenses, it is converted back to sensible heat. At that point, the released energy powers the vertical motion of the air through the thunderstorm, and thousands of these acting together power the Hadley Cell circulation. So some of the heat is going into mechanical energy to circulate the two global working fluids, which are the atmosphere and the ocean.
The eventual destination of all of the heat is back to space, of course. The thunderstorm assists in this radiation in several ways.
• The moist air is concentrated under and in the thunderstorm, while the large cloudless areas around the storm are composed of descending dry air. As a result, although the evaporation is quite high under the storm, the relative humidity in the bulk air drops. Since water is the main greenhouse gas, this dry air allows freer radiation of surface heat to space.
• Once inside the cloud, the air is moved vertically through the center of the cloud to the upper troposphere. During the passage is shielded from interaction with the lower troposphere. It dodges the lower region where the air is dense, and moves rapidly to the rarified upper atmosphere. There, where both CO2 and water vapor are low, the air is free to radiate to space. Rather than radiating the energy from the surface through several recaptures and re-emissions from water vapor and other GHG gases, the barrier is breached mechanically by physically and very rapidly moving the air from the surface to up near the troposphere … don’t move the radiation … move the air.
• From the tops of the equatorial thunderstorms, some of the air will move towards the poles. This air carries both sensible and latent heat polewards.
So in answer to your question, where does the heat go, it goes up, it goes polewards, it goes out to space, and it goes into mechanical work.
w.

Willis Eschenbach

Leonard Weinstein says:
March 11, 2013 at 8:24 pm

Willis,
I enjoyed most of your story (as I enjoy your other ones). There is one issue. The air temperature is colder at higher altitudes (on average) due to the lapse rate. However, when the air circulation carries this air down, it warms up due to adiabatic compression at lower altitude, and does not supply colder air to the surface. That is not part of the cooling effect. The cooling from evaporation, dropping of colder drops (which do not heat due to adiabatic compression), and the fact that wind increases surface evaporation and cools your body (removing sweat faster) are the total effect.

Thanks, Leonard. Indeed, the majority of the cooling must come from the water as you point out. However, the temperatures inside a mature thunderstorm may be quite different from those outside, so two parcels of air (one from inside and one from outside) would not necessarily end up at the same temperature when brought to the surface. Both will be warmed as you point out, but if they start at different temperatures they will end at different temperature. So this may be responsible for a bit of the cooling.
Regards,
w.

Couple of things, I have always looked at a refrigerator as a woking model of planet earths heating and cooling, with the sun as a compressor(heat of compression) and thunderstorms as condensor, #2 what was the reliability of an open shaft refrigeration compressor in salt water environment, great post as always Willis!

Harris

Great post again Willis,
Askøy is an island off the western coast of Norway, close to the city of Bergen. I am sure the vessel hails from there originally.
How it ended up in Fiji is probably a story in its own right…

eyesonu

Willis,
This, IMHO, is one of the most important posts of yours to date with regards to the technical aspects. Like you I am self taught in refrigeration. Bought the books and read every word and made it a point to understand every aspect inside out. Engineering in college only gives one the basic learning tools to work with.
The other engineers reading this post are certainly enjoying it. For all, understand the detailed principles of the refrigeration cycle to the extent that you know your own name. You should then know equally well the gas/liquid/solid properties of a gas (that could be stated better but the point is made). With this knowledge in hand/mind a much better understanding of the so called climate science issues can be evaluated.
Now the real kicker is the absorption refrigeration cycle. That one is like the one in your camper where heat (propane) is burned to cool your refrigerator. That one takes a couple of reads to fully understand. Please note the use of the term “fully”.
Again Willis, this was an excellent post that should help the majority of readers here. There are others who will nit pick on the proper use of certain terms or conditions but that will not take away from what you have written. Any nit picking can be covered in the comments/discussion as you noted in your post. Good work!

Greg Goodman

Another excellent, informative and entertaining articel Willis.
For the most part I would say accurate and clearly explained. However, there one point I think you’re going a bit off the rails.
“Now, let me start by making one thing crystal clear.
THIS IS NOT A FEEDBACK!!!
Instead, it is a natural refrigeration system, capable of cooling the surface well below its starting temperature. Treating it mathematically as a feedback is a huge mistake. It is nothing of the sort. It is a threshold-based emergent phenomenon which actively refrigerates the surface.”
Well, despite saying it isn’t you provide a very detailed explanation of why it IS a feedback. A strong negative feedback. Now if this strong negative feedback produces what you call an emergent phenomenon, fine. The two are contradictory , you’re just giving a name to the mechanism.
You repeatedly say how any hotspots provoke a storm that cools them. I can’t imagine a simpler explanation of what a negative feedback does.
The amplifying effect of the updraught causing increasing surface wind and spray evaporation is a clear positive feedback. So the negative feedback process itself has a positive feedback.
That makes it a very STRONG NEGATIVE FEEDBACK.
In fact, it’s strong enough to create localised emergent phenomena. 😉
The overall effect on tropical climate that you point out is also exactly that of a strong negative feedback: the output variable (temperature) varies only over very small range in response to potentially large changes in the input drivers.
This could be phrased as it having a very low sensitivity to input forcings.
This thread on Climate etc. discusses one paper that is finally recognising the “sensitivity” varies regionally.
http://judithcurry.com/2013/03/10/new-perspectives-on-climate-sensitivity/
Be patient , scientific orthodoxy has the turning circle of massive oil tanker with a full load !
The next question after the tropics is what is the sensitivity at the poles where a lot of the heat pumped out by the mechanism you describe here ends up.
I hope to post on that soon.
One clue is at the end of this graph.
http://climategrog.wordpress.com/?attachment_id=160
Arctic ice cover has reduced notably in response to warmer Atlantic waters, yet the rate of change in ice cover is still swinging around the same value close to zero (longer term average over this data, which only covers post 1980 warming period, is negative.).
That would suggest that the new geography with more exposed water also shows a negative feedback to temperature. Not the positive feedback and supposed tipping points we always hear about.
If the warmer N. hemisphere conditions were simply melting the ice with no negative (or a positive) feedback then the rate of change would be matching the still warm conditions. The divergence at the end suggests something else is happening.
More detail on that soon.

eyesonu

One more comment that I would like to make that is OT but has some relevance (in a weird sort of way) for those who understand the gas laws fully, especially engineering and physics. For an equally mental challange go to the oildrum.com and archive to the era of the Deepwater Horizon spill and follow the discussions paying close attention to Dave Summers who tags/comments as Heading Out. Don’t do this unless you have a few hundred hours to spare or are curious in a technical sort of way.

Greg Goodman

Willis: “The main problem is that the “forcing-feedback” paradigm doesn’t contain a governor, so yes, I do have to deny that their framework is sufficient to encompass the climate.”
It will be interesting to see you details of “governor”. You are correct that a simple linear feedback is inadequate. That does not mean you need to abandon the whole idea of feedbacks. I suspect you governor may be a non linear negative feedback as I outlined above: a negative feedback that whose magnitude itself has a positive feedback. I’ll have to wait to see you details but I think you, I and Alex are saying the same thing.

dp

Sometimes I think you are a clone of me. I learned refer systems on cars and later turned that to cooling yachts and work boats. Crazy world, eh. Anyway – your analogy goes all to hell because none of this works withing energy entering the system. Don’t care if it is in Tristan d’Cunha, PNG, or in the core of my Kelvinator, nothing does anything without energy going in. I’d accept any refinement that ends up with an imbalance of energy along the transfer path.
You start your cycle with a hot spot but that hot spot didn’t arrive from nowhere. To be complete you need to show how that spot got hot. It was put there and that putting put the rest in motion. Here’s the point. This is all – repeat that – ALL energy positive. Yes, some places may be cooled by energy movement, but this is, and always will be an energy positive operation. The only way the excess energy can leave the system is by radiation to the great voids of infinite space.
Any energy that does not immediately go there remains in the local (Earth) system but displaced from the point of origin. So you can cool stuff here but at the expense of heating or sustaining warmth there. No free lunch.
But that isn’t the end of it – that heat is moved by T-storms somewhere useful if you are a mad greeny crazed with passion of containing global warming. Those T-storms move that heat from the surface to very high altitudes possible faster than it can have gotten there by radiation, ping ponging between CO2 molecules (convection), and physical abuse (Conduction). This is good because it puts that heat very close to the blackness of space with little in the way of CO2 density to impede. The extinction range of CO2 at 30,000′ is far greater than it is in a laboratory where they haul in great wealth to misunderstand all this. The consequence is that surface energy which radiates only from GHG’s by the way, are radiating madly into space. It is worth knowing that the GHG’s radiate like a point – in all directions, but at altitude more directions point at stars than our Earth and so more leave the system with fewer intervening hops among GHG molecules. And this radiated heat will include in large part that heat that started the process in the first place.
So you are ultimately correct but not perfectly accurate, perhaps. I do agree with you that T-storms on average will move net positive energy out of the Earth system by convoluted means powered by the sun.
As you know we cool yachts and workboats by piping cabin heat into the ocean. You wouldn’t be, but lay people would be amazed what a refrigeration mechanic can yard in during a warm Acapulco summer. Axe me how I know.
I can see a fat carbon tax opportunity coming around the corner when Hansen puts a bug in Gore’s ear about this.

Michel

@Willis: you are a rainmaker!
On refrigerator without compressor see: http://en.wikipedia.org/wiki/File:Einstein_Refrigerator.png

Wally

The bit about thunderstorms reminds of travelling through Greece when I was 14.
Every day about 5pm, at the end of a hot hot day, the clouds would form and POW, down came the rain. Pelting down for about 15 minutes. Then the rain had kind of had enough, all stopped, and things were cooler and of course far more humid.
This happened pretty much every day. I’m pretty sure it was Greek summer time.
But my point is, that cycle of evaporation, clouds, rain, cooling, was very very obvious. In the places where the are thunderstorms every day, or pretty much every day, then anyone reading what you wrote would be instantly familiar.

ImranCan

Your science credentials might come across a little better if you included a phase diagram and maybe some simple explanation as to how much energy would be required to move the refrigerant to the mountain top instead of just using the compression energy on site. Otherwise stick to the autobiography …

Superb yarn and exposition on thunderstorms! You’d have got on well with Frank Ludlam – he was so keen on weather he taught himself a lot – he was appointed as a lecturer without even a bachelor’s degree in 1951, and was a professor of meteorology by 1965 – at a time and place where being a professor was a great achievement. I was a postgrad student in his department the year before he died in 1977. I feel sure he would have had no truck with the casual alarmism which has poisoned his beloved subject. I remember him smiling at us in one of his all-too-rare lectures when we demanded guidance us as to what we should do about the threat of a new glaciation – the media scare of that time, aided and abetted by such as Stephen Schneider. He paused, smiled gently at us, and said if we really must do something, we might advise our children to build their houses 50m (I can’t recall the exact figure, but it was small) closer to the equator than our own. Now that helped us get the scare into perspective. His posthumously published book, ‘Clouds and Storms’, can still be obtained on the second-hand market (http://www.amazon.com/Clouds-Storms-Behavior-Effect-Atmosphere/dp/0271005157). It is a beauty.

Jon

Just a bit worried about having people drink -40° vodka. From living in a cold climate in my experience is that vodka left outside in -35°C will freeze to a slur, so yours must be really strong. AND downing -40° liquid may cause permanent frost damage to your throat

Willis,
following your response to Leonard Weistein, I can assure you that the air descending along with the rain fron a cumulonimbus cloud is colder then the surrounding surface air, but not because its origin is aloft, at colder temperature.
High in the troposphere, expecially in presence of a convective tower, potential temperature is much higher than that at the surface. Every parcel of air descending from aloft would gain adiabatic heat and have a much higher temperature when it gets to the surface.
Anyway, the downdraft is colder.
Why?
Because rain passes trough drier, non saturated air before it gets to the surface.
Some of that water will evaporate again (in some very dry climate even 100% evaporates), cooling the downdraft much more than the heat gained from adiabatic compression.
Also, melting of snow/ice, higher up along the downdraft, will have a significant colling effect.
In conclusion, again, the phase change of water is what adds to the cooling of the Earth surface.
Regards

Joe Public

@ ed mister jones on March 11, 2013 at 9:45 pm
“But the Heat does wind up somewhere, and if that somewhere doesn’t pass the heat somewhere else yet again, then the first somewhere is going to get warmer (as happens when you run an ordinary refrigerator in an unventilated room). . . . ”
When you leave the refrigerator door open in your kitchen, it warms the room. Simply because you’re using an external power source to move the refrigerant around the system.

Nippy

@Willis
Having installed refrigeration plants on fishing vessels I was alerted to the effect of leaking refrigerants on internal combustion engines(http://www.google.ie/url?sa=t&rct=j&q=freon%20and%20engine%20oil&source=web&cd=1&sqi=2&ved=0CCsQFjAA&url=http%3A%2F%2Fexchange.dnv.com%2FCasualtyInformation%2FDocuments%2FDownload%2F45&ei=_wc_UYT3Jouy7AaSmoHICQ&usg=AFQjCNEnPn3Lk7lO1lE5EgvJpvgqLKar4w&bvm=bv.43287494,d.ZGU&cad=rja), so never did the lay shaft solution for refrigeration. Did lots of other lay shaft solutions in marine work boats, great fun and greatly satisfying to see designs making someone a living. (Also worked on Saturn C5, the ‘interstaging’ ring?.)
Absolutely love your writings. I find them technically very accurate and illuminating, and your life stories most entertaining.
As you point out moist air is lighter than dry air and as the rising air expands against gravity the work produced drives the weather, the giant gas turbine in the sky. (Not a mention of CO2).

Anyone who doubts should spend a summer on the Gulf Coast. The subtropical weather pattern is dominated, not by continental weather patterns, but by a 30% chance of “popcorn showers” every afternoon. (On time lapse images the storms pop up from nothing like popcorn.) Rarely does the thermometer reach 100F. Hurricanes have the same effect on a grand scale.

William Truesdell

“WARNING—this post is a 50/50 mixture of science and autobiography, call it autosciography. If that makes your brain explode, DO NOT push the button marked “Continue reading →”.
I appreciate your warnings but the main issue most had with you was not just the lack of science in your Vietnam War post, but the politics and the standard comments from the anti-Vietnam War playbook.
I have had no issues since then, so your warnings (not as mature as they could be- “makes your brain explode”) are appreciated just in case you want to pontificate politically again.
Also like it that you are now including gradations in the content (50/50).
I do read most of your posts and appreciate your exceptional insight into the problems of weather/climate. Keep it up.
W.M. Truesdell

wsbriggs

Just a note on the Einsteinian refrigerator, he and Leo Szilard invented it while thinking about magnetorhydrodynamics – Einstein was both a theoretician and and experimentalist when he was young. It worked brilliantly, but the cores in the pump screamed like a banshee from magnetically induced pulses – it got quickly turned off.

I think you would have got on well with Frank Ludlam. He taught himself a lot of meteorology. He was appointed as a lecturer without even a bachelor’s degree and became a professor a few years later – at time and place when getting to be a professor was a very big deal indeed. I was a postgrad student in his department the year before he died all too young in 1977. I like to think that he would have scorned the casual alarmism which has poisoned so much of his beloved subject in the decades since. I remember at the end of one of his all-too-rare lectures, we students pestered him for guidance about what to do in response to the then current scare in the media about the threat of an imminent glaciation – a media position aided and abetted by such as Stephen Schneider. He paused, smiled gently at us, and said if you really must do something, then you might consider advising your children to build their houses 50m (I can’t be sure of the number he used, but I do recall it was small) closer to the equator than your own. Even that, he hinted, might be a gross over-reaction given the level of knowledge on the topic. His posthumously published book ‘Clouds and Storms’ is still obtainable on the second-hand market, and is a beauty.

John Shade

I think you would have got on with Frank Ludlam. He taught himself a lot of meteorology. He was appointed as a lecturer without even a bachelor’s degree and became a professor a few years later – at time and place when getting to be a professor was a very big deal indeed. I was a postgrad student in his department the year before he died all too young in 1977. I like to think that he would have scorned the casual alarmism which has poisoned so much of his beloved subject in the decades since. I remember at the end of one of his all-too-rare lectures, we students pestered him for guidance about what to do in response to the then current scare in the media about the threat of an imminent glaciation – a media position aided and abetted by such as Stephen Schneider. He paused, smiled gently at us, and said if you really must do something, then you might consider advising your children to build their houses 50m (I can’t be sure of the number he used, but I do recall it was small) closer to the equator than your own. Even that, he hinted, might be a gross over-reaction given the level of knowledge on the topic. His posthumously published book ‘Clouds and Storms’ is still obtainable on the second-hand market, and is a beauty.
[Note to moderator/ I have tried twice to get this in via WordPress log-in, but each time I failed to get a system acknowledgement. My apologies if they, and this, are in some queue for you somewhere. I hope you will delete the least well-written of the three if so, and if you let one through at all]

Duke C.

Here in the Mojave Desert, we’ve been using a variant of this principle for as long as I can remember: Swamp Coolers. Nothing more than an enclosed circulation fan that pulls hot, dry desert air over a series of pads saturated with water. The cool moist air moves through the interior where it absorbs heat, then exits through an open window on the far side of the house. Biggest advantage is no compressor or exotic refrigerants. Only disadvantage is when the late summer monsoons blow in, which raise the relative outdoor humidity.
These units are efficient enough to keep the interior ~30F cooler than the outside temp, even when it’s 110-115F.

Sensible heat is the heat difference you measure with a thermometer. The phase changes in the refrigerant are called Latent Heat of Vaporization and Latent Heat of Condensation. The atmosphere is an ‘open refrigerant’ as there is no ‘piping’ separating the working fluid during these changes. This same system is at work in the ocean with high temp/pressure gases at sea floor vents, which condense at the sea floor and evaporate in the water column or at the surface. Massive amounts of air move veritcally within thunderstorms, creating vertical wind shear. The Daedalus cycle would never work as the thermal gradient can never overcome the liquid and gas line friction losses. Man has designed systems using the Latent Heat of Solidification, called “Heat of Ice” systems which use a smaller system working 24 hrs a day and storing needed daytime peak load as ice. There are also phase change systems which “store” thermal energy using salts. Check the EngineersToolbox.com for the thermal capacity of water, it is double that of any other listed substance. We are blessed to have a planet covered with a life giving refrigerant.

Mike M

I also think of it as a feedback mechanism working in a localized fashion. In the tropics, the time thunderstorms occur is on average between ~3PM to ~5PM after the sun has heated up the surface – not at 9AM, not at 8PM. I think it explains why the tropical areas exhibit the least ‘global warming’, they have the water to enable negative feedback as well as positive feedback. The hotter it gets just after noon – the bigger the thunder storms. At night the water vapor helps hold the heat in. Desert conditions = no feed backs either way = wild temperature swings.
And, as DP above noted, I’ve been screaming for years about how the latent heat is going up to altitude totally unimpeded by GHG’s along the way. The simple measurement of how much heat is re-radiated up there is precipitation. Every drop of liquid water that comes down precisely equals a drop’s worth of latent heat that went up as a vapor; the only variability in the net outbound radiation is how high it went before it condensed.

Josh C

Governor system, or a ‘Regulator’ as I understand it – I think the process is only really screwed up by the fact we have large land masses that interfere with the normal system. Lacking the ability to rapidly generate clouds due to insufficient available water means the land mass (and related land covering) is the real culprit for disorganizing the system from being a regulated constant max temperature no matter what the input.
Thanks for the insight – and the stories. Having been self taught on quite a few subjects myself I enjoy hearing it in action.

Gary

As you’ve point out in other posts and imply here, Bejan’s Constructal Theory describes how this and other natural systems tend toward the most efficient ways for moving energy and mass through the flow channels. Empirical evidence has piled up in so many cases that it’s very hard to argue, unless you’re blind to it, that human-caused alterations of the environment would be globally catastrophic. Local disaster, yes. It’s plenty easy to make a mess like Chernobyl or the Dust Bowl. But even then the natural systems get to work repairing and restoring flows to optimum levels. There’s an inherent characteristic of systems to revert to the mean. Equally fascinating is the capacity to temporarily diverge from the mean a bit and provide some variability and thus more “surface area” (a/k/a “niche space” for occupation.

Gary Pearse

Willis, you are indeed a “can do” man and an inspiration for us comparative wafflers. You could have easily gone right into the refrigeration business (or maybe any business with your confident attitude and smarts). I’m an engineer (and geologist and economist – didn’t know what I was going to end up doing) and here is my refrigeration story. I worked for the Geological Survey of Nigeria (GSN) in the mid-60s and was sent off to the very dry and hot northwest province of Sokoto. When I went to “stores” to get my gear, I noticed a few small (2cubic foot?) kerosene refrigerators – you know the magical ones that use fire to freeze the icebox? I learned that, in the past, some geologists had used them in the field. I decided to take one after trimming the wick and firing it up to be sure it was working. Here is an explanation of how it works.
http://en.wikipedia.org/wiki/Absorption_refrigerator
Set up in my camp – two tents and refrigerator in a shaded area- myself and the GSN driver, I would go out for a day’s mapping, returning to the luxury of cooled foodstuffs and a tiny ice cube tray. It was in the middle of Ramadan (no food or drink while the sun is up for the faithful) and news of my magical refrigerator spread widely, finally reaching the Emir of the region. He sent an envoy to ask me if I would kindly give him some ‘kankale’ for his drinking water for after the sunset, to which I agreed.( pron.”kunkelly” it is the Hausa word for hail to which they attribute magical and medicinal values (scorpion bites, etc) and which they gather during a storm and place in straw lined covered pits (a village of people can probably gather a ton or so from a good storm). I also put my thermos into the fridge to have it cool for the job. The envoy would return in the evening for the kankale. Wouldn’t you know it, that I returned a couple of hours before sunset to find black smoke coming out of the fridge chimney! Yoikes, I checked the ice cubes and found little platelets of ice floating in the melt water. I had to trim the wick and get it burning properly and I had also to fan the condenser vigorously for an hour – I didn’t want to disappoint! At the appointed hour, the envoy arrived on foot with a small gourd to receive the ice. I quickly put the not quite totally refrozen cubes into the thermos, got driver, envoy and myself into the Landrover and raced off to the Emir’s main village where the Emir was waiting with an enamel cup of water in a crowd of villagers there to witness the event. I removed the thermos cork and poured with a musical tinkle the woefully thin wafers of ice into his cup. Everyone cheered as he downed the water which at least had been partially. After that I didn’t want for firewood, bananas, the odd chicken (live), etc.

Mark Bofill

Greg Goodman says:
March 12, 2013 at 12:51 am

You repeatedly say how any hotspots provoke a storm that cools them. I can’t imagine a simpler explanation of what a negative feedback does.
————
I don’t disagree with you strictly speaking, but I took Willis’s point to be that tropical thunderstorms shouldn’t be evaluated as a ‘traditional’ negative feedback because of the localization, quick response time, and lack of dependence on forcing of the phenomenon; basically the whole ‘governor’ mechanism thing.

David

Seen in the classified ads in our local (U.K.) newspaper:
‘For sale. Refrigerator. Not working; otherwise good condition.’
Make a good bookcase, then…

Matt Skaggs

I don’t remember a “governor” being a fundamemtal building block in control systems theory, so I for one am very interested in hearing how it is different from a feedback.

perlcat

Man, you can sure spin a yarn! Enjoyed this immensely! As to the people not ‘getting’ the “Not a feedback” bit — the Chicken Littles of the world have all warped the definition of the term to mean solely positive feedbacks — as always, their motto remains “If the data does not fit, you must omit.”

Also the fact the icy top of a thunderhead spreads out as the “anvil-top” spreads out that air in a manner that effectively radiates the heat into space.
I always suspected that the model’s “tropical hot spot” (which shows no sign of actually existing) was created because some agenda-driven modeler knew, down deep in his soul, that tropical thunderstorms governed the tropical heat, and therefore he wanted to create a hot “lid” that would prevent those thunderstorms from occurring, because otherwise Global Warming would fail to happen within his model.
(Sorry, but those modelers activate my suspicious side.)