TAO And TAO Again

Guest Post by Willis Eschenbach

Impelled by my restless curiosity, I’ve returned to the TAO buoy dataset to investigate a claim by Dr. Ramanathan of a “super-greenhouse” effect. The TAO buoys are a number of moored buoys located across the Pacific. The TAO data is available here.

TAO Buoy LocationsFigure 1. Locations of all of the sites of the TAO buoys, stretching from above Australia on the left, across the Pacific to off of South/Central America on the right.The buoys collect information on some 17 different variables. The graphic is from the data selection page linked to above. Solid blue squares show buoys which record the currently chosen variable (in this case SST). Empty blue squares show buoys which do not measure the current variable.

I am using the sites on the Equator itself because they have the widest variety of data, including rainfall, air temperature, sea surface temperature, pressure, winds, etc.

Now, here’s the statement by Dr. Ramanathan that I wanted to investigate:

The greenhouse effect in regions of convection operates as per classical ideas, that is, as the SST increases, the atmosphere traps the excess longwave energy emitted by the surface and reradiates it locally back to the ocean surface. The important departure from the classical picture is that the net (up minus down) fluxes at the surface and at the top-of-the atmosphere decrease with an increase in SST; that is, the surface and the surface-troposphere column lose the ability to radiate the excess energy to space. The cause of this super greenhouse effect at the surface is the rapid increase in the lower-troposphere humidity with SST; that of the column is due to a combination of increase in humidity in the entire column and increase in the lapse rate within the lower troposphere. The increase in the vertical distribution of humidity far exceeds that which can be attributed to the temperature dependence of saturation vapor pressure; that is, the tropospheric relative humidity is larger in convective regions.

The “convective regions” are the warmer tropical regions where convective thunderstorms are a frequent occurrence. And his claim is kind of logical, since evaporation is in part a function of temperature, with increasing temperature leading to increasing evaporation.

However, my own experience of living in the tropics led me to suspect that contrary to Ramanathan’s claim, the relative humidity (RH) would in fact be lower in the convective areas, and lower during the times of day when there are the most thunderstorms. I thought this for two reasons.

The first is my own experience of a couple of decades of working in these tropical regions. My observations are that before the afternoon thunderstorms come rolling in, the air is often “sticky” with moisture. After the thunderstorms, on the other hand, the air feels dryer. Anecdotal, I know, but I tend to trust my own experience over theory …

The other reason is that although there is a lot of moisture moving around during the thunderstorm regime, it’s mostly concentrated under and inside the thunderstorms, and that moist air is moving rapidly upwards to have the water wrung out of it by the thunderstorm. But in the much larger area in between the thunderstorms, you have dry descending air. This is air from which the water has been stripped by the thunderstorm through a combination of condensation and freezing.

And as a result, my expectation was opposite to that of Ramanatan—I expected that the more convection, the lower the relative humidity.

So, off to the data, with a few digressions along the way around and back. First, let’s look at sea surface temperatures. This is all two-minute data, that is to say the sea surface temperature (actually one metre below the surface) is recorded every two minutes.

TAO daily cycles SSTFigure 1. The daily average variations in sea surface temperature at eight equatorial Pacific TAO buoys.

Now, I’ve colored the data from light blue (coldest) to red (warmest). Note that this is also in order by location—the further west you go along the Equator in the Pacific, the warmer are the ocean temperatures. Note that the water temperatures rise evenly and fairly rapidly from early morning to a peak at about three pm. Then over the next sixteen hours or so, the ocean gradually cools down again.

There is kind of a subtle oddity in the daily variations. This is that the warmer the ocean overall, the less daily variation there is in the sea surface temperatures. To illustrate this, Figure 2 shows those same daily ocean temperature cycles as anomalies around their respective averages.

TAO daily cycles SST anomaliesFigure 2. The daily variations in sea surface temperature at eight equatorial Pacific TAO buoys, expressed as anomalies about their respective means. Red shows the warmest buoys, light blue shows the coolest buoys.

Curious. The sea surface temperature in the warmer part of the Pacific don’t vary as much on a daily basis as the temperatures in the cooler part.

As might be imagined, a similar situation holds with the air temperatures. The further west you go, the warmer the air temperatures you’ll find. Figure 3 shows the air temperatures at the same buoys shown in Figures 1 & 2.

TAO daily cycles temperatureFigure 3. The daily variations in air temperature at eight equatorial Pacific TAO buoys.

As with the sea, the temperatures increase with the distance west. However, the changes in the air temperatures are more complex, because of the emergent atmospheric phenomena of cumulus clouds and then thunderstorm clouds. This becomes visible when we look at the air temperature anomalies.

TAO daily cycles temperature anomalies

Figure 4. The daily variations in air temperature at eight equatorial Pacific TAO buoys, expressed as anomalies about their respective means. Red shows the warmest buoys, light blue shows the coolest buoys.

Figure 4 is perhaps the strongest evidence of the existence of a cloud-based temperature regulation system that I’ve found so far. Let me see if I can explain why. Here’s a graphic showing the situation at dawn …

tropical diurnal early morningFigure 5. The general situation in the tropical convection areas in the early morning.

As you can see, at this time of day clouds are uncommon. As a result, Figure 4 shows that the temperature rises very rapidly for a couple of hours after six AM. However, as the day warms up, at some point a threshold of emergence is passed and the first thermal cumulus clouds start to form, resulting in a change of atmospheric state. Within an hour or so, in place of clear skies, there will be a fully developed cumulus field covering the entire surface.

tropical diurnal late morningFigure 6. The general situation in the tropical convection areas in the late morning, with a fully developed cumulus state.

In the colder areas, the cumulus do not form as early or as strongly, so they don’t have as large an effect. But as you can see in Figure 4, in the warmer areas there are so many clouds that the temperature actually drops for three hours, from about nine o’clock to about noon. And as Figure 4 shows, the further west you go, the warmer it gets, and the stronger the cumulus cloud effect gets.

However, even in a fully developed cumulus state, there is not continuous cloud cover. The cumulus clouds can be thought of as flags, each one marking an area where there is an upwelling column of air. However, in between the upwelling air columns and their respective clouds, perforce there must be larger areas of slowly downwelling air. And these areas don’t have clouds. As a result, although the temperature rise is reduced or reversed from nine AM until noon, the sun still gets stronger over that time, and at some point around noon the cumulus shield is not enough to stop further temperature rise.

In the afternoon, with the continuing temperature rise, a new threshold is passed and we get another change of state. This one involves the formation of thunderstorms. These astounding emergent entities pipe air vertically at very high speeds, removing heat from the surface and converting it to mechanical motion. They also cool the surface in a number of other ways.

tropical diurnal early afternoonFigure 7. The general situation in the tropical convection areas in the afternoon to night, with a fully developed cumulonimbus (thunderstorm) state.

There is an oddity, which is that when the thunderstorms develop, the albedo goes down. This is because the vertical motion is so fast in the thunderstorms that they have a proportionately much larger surrounding cloud-free area of dry descending air on all sides of them.

Now, I said at the outset that there would be “a few digressions along the way around and back” to Ramanathan. So with those as the digressions along the way around, let me come back to the topic by saying that these large areas of descending dry air are the reason that I thought that Ramanathan was wrong. Remember that I’d disagreed with Ramanathan’s claim, viz:

The cause of this super greenhouse effect at the surface is the rapid increase in the lower-troposphere humidity with SST; … the tropospheric relative humidity is larger in convective regions.

And what do the TAO buoys say about the relative humidity (RH)? Well, here are the daily cycles in RH for the same eight TAO buoys …

TAO daily cycles rel humidityFigure 8. The daily variations in relative humidity (RH) at eight equatorial Pacific TAO buoys, expressed as anomalies about their respective means. Red shows the warmest buoys, light blue shows the coolest buoys.

Now, the colors of the buoys are the same. Coldest is light blue, warmest is red. But instead of the RH increasing with sea surface temperature (SST) to engender a “super greenhouse effect”, the reverse is true. As the ocean temperature rises, the relative humidity falls.

How about during the course of the day? My hypothesis regarding emergent phenomena says that the relative humidity should be lowest during thunderstorm time in the afternoon. The next figure shows the RH all of the buoys once again as anomalies, so we can compare their daily variations.

TAO daily cycles rel humidity anomalyFigure 9. Daily variations in relative humidity (RH), shown as anomalies about their respective means.

Comparing this to the SST, we see that contrary to what Ramanathan claimed, when the SST is largest, the relative humidity is the lowest.

Now, all these findings shown in Figs. 8 & 9 are curious, because Ramanathan clearly believes that relative humidity is invariant under changes in the climate. He says elsewhere (emphasis mine):

A simple explanation for the water-vapor feedback among the early studies of climate sensitivity was the fact that the relative humidity of the atmosphere is invariant to climate change. As Earth warmed, the saturation vapor pressure (es) would increase exponentially with temperature according to the Clausius–Clapeyron relation, and the elevated (es) would (if relative humidity remains the same) enhance the water-vapor concentration, further amplifying the greenhouse effect. Although it is well known that atmospheric circulation plays a big role, a satisfactory answer as to why the relative humidity in the atmosphere is conserved is still elusive.

But according to Figure 8, the relative humidity in the convective zones of the Pacific varies inversely with sea surface temperature. And this is true both for long-term average sea surface temperature, as well as for the daily average temperature variation.

I can’t say that I have any great conclusions from all of this. However, it does appear that the modelers’ claim of strong water vapor feedback rests on the idea that relative humidity stays constant in the face of warming. If these TAO data findings are correct, and if relative humidity more generally is not constant with respect to temperature, it would seem that this would greatly reduce the amount of purported water vapor feedback …

In any case, it would seem to falsify the idea of a “super greenhouse effect” that is driven by relative humidity as Dr. Ramanathan claimed.

Always more to consider, always more to learn.

My best wishes to all,


PS—If you disagree with someone, please have the courtesy to quote the exact words you disagree with. In that manner, we can all understand exactly what you are disputing.

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February 18, 2015 3:29 am

Sorry, total rubbish. Increased convection means increased latent heat requirement leading to a cooling which is why tropical wet areas are cooler than deserts with zero water vapour. Radiation from a cool area cannot increase the temperature of a warmer one, 2nd law of thermodynamics.
If you challenge the 2nd law then make your fortune and design a perpetual motion machine using the GHE.

Reply to  johnmarshall
February 18, 2015 4:42 am

To John Marshall: which are the exact words that you disagree with in the post?

Robert of Ottawa
Reply to  johnmarshall
February 18, 2015 5:57 am

Quite clearly, the warmer the atmosphere, or SST, in the tropical Pacific, the lower relative humidity; which reveals Dr. Ramanathan’s statement a crock.

Ed Zuiderwijk
Reply to  johnmarshall
February 18, 2015 5:58 am

Actually, John, it’s the 1st law that says that.

Reply to  johnmarshall
February 18, 2015 8:20 am

Johnmarshall, I almost never see where the 2nd Law is necessary to invoke in climate discussions. 1st Law is all that is necessary — net heat-fluxes. W/almost no exceptions, invoking 2nd Law means someone doesn’t know what they’re talking about.

george e. smith
Reply to  beng1
February 18, 2015 3:50 pm

Well you said it.

Reply to  johnmarshall
February 18, 2015 11:38 am

Your first sentence is good. Your second sentence is a non-sequitor. The Second law is a dangerous thing to invoke because it involves the totality of existence. It is very easy to misapply (especially with radiation, the most misunderstood of heat transfer methods. Specifically, the emitting of radiation is independent from the receipt of radiation. Both of which are net-entropic-positive events. Therefore, yes, a cool body can radiatively warm a wamer body).
Way back in school, thermodynamics was effectively a class about the second law. We lost a lot of potential Chemical engineers who just couldn’t cut it in relatively simple calculations. Pretty much, if you EVER invoke entropy except in musing about the end of times or in calculating engine efficiencies, you are probably misusing it.

george e. smith
Reply to  benofhouston
February 18, 2015 4:21 pm

“””””….. It is very easy to misapply (especially with radiation, the most misunderstood of heat transfer methods. …..”””””
It sure is, since EM radiation is no more a heat transfer method, than is an ordinary grocery shopping cart.
EM radiation IS a method for transferring ENERGY. All energy is NOT “heat” (noun).
Nor is coal a form of heat, but you can move it from one place to another in a shopping cart, and release some of the stored chemical energy in it in the form of (waste) heat.
Heat requires physical particulate matter for its transport, either by conduction and by convection, and the amount of “heat energy” is directly describable in the form of the purely mechanical motions of that particulate matter. Those same mechanical movements are an essential part of the concept of Temperature.
Only “Heat” energy can change the Temperature. EM radiation is not aware of Temperature and can neither sense it nor change it.
But EM radiation can be (virtually 100%) converted into waste heat energy, but the converse is NOT true.
Heat energy cannot ever be converted 100% to ANY other form of energy. But almost any other form of energy can be converted (irreversibly) into heat.
Consider transferring “heat” energy by conduction along a copper rod between the sun at 6,000 K and the earth at 288 K for a temperature difference of 5712 K over a distance of 93 million miles, or 9.3E7 x 5280 x 0.3048 m = 1.5 E11 meters.
Copper has a thermal conductivity of 400 W/mK.
So the rate of heat flow from sun to earth along the copper rod is:
400 x 5712 / 1.5 E11 = 15.23 microwatt per square meter.
Well that assumes that the rod doesn’t evaporate, or radiate, so it has a thermal guard ring around it to prevent heat loss out the sides of the rod.
Well you can improve the heat conduction to the earth by using diamond instead of copper, since it has a conductivity of 1,000 W/mK. That’s a whopping 37.5 microwatt per meter squared.
But radiation from the sun can with present technology be converted at about 43% efficiency to DC electricity with present solar cell technology.
That electricity can be converted with about 58% efficiency into red or yellow EM radiant energy and beamed back out into space or back to the sun, with almost no atmospheric loss.
So that is solar energy that never ever gets converted to “waste heat” here on earth.
Well you can also convert the solar energy into wood or food or living organisms; none of which would ever be described as “heat”.
That’s why Kevin Trenberth can’t find his “missing heat”. He assumes that all the eM solar radiation arriving on earth is “heat”. It’s NOT heat.
We make all the heat here on earth, and there is not as much heat made as Kevin imagines.

Reply to  benofhouston
February 20, 2015 3:59 am

This is exactly why we’re left in this sorry state of affairs, where the AGW movement is free to continue to bulldoze through with their pseudoscientific nonsense. Because they know they’ve got the lukewarmers (the ‘half-sceptics’) to cover their backs, firmly believing (and promoting the idea, like here) that ‘Radiation’ is some kind of magical, celestial entity that is somehow exempt from the 2nd Law of Thermodynamics. Listen to yourself. Read what you just wrote, benofhouston:
“Therefore, yes, a cool body can radiatively warm a wamer body.”
Are you being serious!?
There is no more a bidirectional thermodynamic ‘transfer of energy’ in a radiative heat transfer than it is in a conductive heat transfer.

george e. smith
Reply to  benofhouston
February 20, 2015 10:43 am

February 20, 2015 at 3:59 am
Because they know they’ve got the lukewarmers (the ‘half-sceptics’) to cover their backs, firmly believing (and promoting the idea, like here) that ‘Radiation’ is some kind of magical, celestial entity that is somehow exempt from the 2nd Law of Thermodynamics. …”””””
A fundamental law of the propagation of electro-magnetic radiation, whether in free space, or through some optical system (any optical system), is the concept of the invariance of ‘etendue’ which is a three dollar French word for ‘throughput’.
At any point in an EM field, the product of an elemental area times the elemental solid angle of the flux through that area, is a constant, and the integral of that elemental product is fixed, and cannot be changed by any optical system.
In optical system design this is manifested by the paraxial (small angle and ray height) quantity n.h.u where n is the refractive index of the medium, h is the ray height from the optical axis, and u is the edge ray angle. This is known as the Lagrange invariant.
Away from the paraxial region, this rule becomes N.H.Sin(U) in a planar system, or the square of that product in a three dimensional system, often referred to as the optical sine theorem . Put into words it expresses the notion that no optical system can form an image whose ‘brightness’ (radiance) is higher than that of the source. Since the rays are reversible (in geometrical optics) this also implies that no system can make an image that is less bright than the source. Well of course practical systems contain media, where the radiation gets absorbed in whole or in part, or splits into several directions.
If the invariance of this quantity were not true, then an optical system that created a brighter (higher radiance) image than the source, could take the energy from a black body radiator source, at some Temperature Ts, and inject it into an image black body at higher radiance, and thereby drive the image body to a higher Temperature than the source body, which the second law prohibits.
One of the first proofs of the optical sine theorem was given by Rudolph Clausius, using this second law demonstration.
The invariance of etendue is a major stumbling block in solid state lighting.
LED die, have very small radiating surface areas, with extremely high radiance values.
When used in some optical system to create a light source of some source area, and solid angle of distribution, the area and solid angle can be exchanged with each other, but the product must remain constant. The only way around this is to employ some statistical or time multiplexing contrivance to make a source appear larger but only for some fraction of the time.
For example, a once cm square source, could be mechanically scanned back and forth over a one square meter area, at high speed, but it would only appear in any location for one millionth of the time, and the eye would perceive it to be a million times dimmer.
Of course you could angle scan it instead with the same result.
In practice, diffuse surfaces or volumes are used to scatter the photons, which is a time multiplexing process. Unfortunately, this always results in back scatter, and wide angle scatter, both of which are loss mechanisms.
In white LED devices, you get one ‘get out of jail free’ card, in that you start with an extremely bright blue LED and you absorb much of the blue light in some much larger area of phosphor, which then radiates the green yellow and red portions of a white light spectrum. But note that you still have a blue etendue problem, so the phosphor also is required to scatter the remaining blue photons as well.
So if those ugly white LED street lights or car headlights bug you; now you know, the engineers have not solved the invariance of etendue problem yet. When they do, the LED headlights will have the same eight inch or so diameter as an ordinary incandescent car headlight.

Reply to  benofhouston
February 24, 2015 1:48 am

You are both willfully misunderstanding my statements, and George, your use of vocabulary to trash my post simply shows that you really don’t understand what you are talking about. How’s this for a little example:
If you have an isolated body in space at temperature X. No conduction, no convection, no incoming radiation, no nothing. It will radiate energy out via blackbody radiation and gradually lower in temperature.
Now, same situation, but with a second body next to it at temperature X-1. This is also radiating blackbody radiation via the same processes.
Basic thought experiment, which body cools more slowly? As any idiot can see, the second. Why? because it is being struck by the blackbody radiation of the slightly cooler object. This radiation doesn’t magically disappear. Some is reflected and some is absorbed just like every other bit of radiation in existence (photons don’t have memory of the temperature of the body that they came from, which is ENTIRELY THE POINT). The absorbed radiation changes to heat. Therefore, it is perfectly acceptable and correct to say that this body is being warmed by the presence of a colder body. The net transfer is, of course, in the other direction as the warmer body gives off more radiation, and thus even in an otherwise empty universe, entropy rises. However, both objects are warmer because of their shared presence.
You simply give fodder to the alarmists with your willfull misapplication of extremely basic physics and misstatement of the problem.

Reply to  johnmarshall
February 18, 2015 2:45 pm

Uh, correct me if I’m wrong but the 30 degree latitude desert belt may have a higher measured temperature than the tropics (during the day) but measured temperature is not the same as heat. Tropic air has more specific heat because it contains a much higher relative humidity. So, it’s not correct to say that tropical wet areas are cooler than hot deserts when referring to heat. Heat is transferred to higher latitudes from the tropics and no laws of physics are broken.

Reply to  RWturner
February 20, 2015 4:18 am

“(…) it’s not correct to say that tropical wet areas are cooler than hot deserts when referring to heat.”
But we’re not referring to ‘heat’ (by this I guess you mean rather ‘energy content’, which is equal to the thermodynamic term ‘internal energy’ [U]; thermodynamic ‘heat’ [Q] is energy spontaneously transferred unidirectionally from a hot place to a cold place, not something contained within a system). We’re not referring to ‘energy content’. We’re referring to temperature. Much H2O in an atmospheric column (WV + clouds) will (by observation) on average (annual mean) make the surface beneath cooler (temperaturewise), assuming ToA incident solar is equal. Hence, there is no net radiative ‘greenhouse effect’ (i.e., net ‘absolute warming’ effect) on the surface from having H2O in the atmosphere above it.
“Heat is transferred to higher latitudes from the tropics and no laws of physics are broken.”
Did anyone suggest physical laws to be broken by this process?

Reply to  johnmarshall
February 24, 2015 12:22 pm

I am no huge fan of this author, but he is correct on this and you are bloviating.

Evan Jones
February 18, 2015 3:45 am

Excellent independent review.

February 18, 2015 3:53 am

That lucky old sun has nothing to do, but roll around heaven all day.

A C Osborn
February 18, 2015 3:58 am

Willis, that is a very nice piece of work that uses “DATA” rather than models and theories. It would be very nice if some so called Climate Scientists tried it it some time.
I was not too surpried by the “This is that the warmer the ocean overall, the less daily variation there is in the sea surface temperatures. ” as I supposed that the warmer Seas are already closer to the “Evaporation Point” at the water surface and thus start the cooling process that much quicker.
Is this not more reinforcement of your “Water and it’s evaporation is the Control knob” theory?

February 18, 2015 4:09 am

I would have guessed that absolute humidity is more important.

Joe Born
Reply to  Slywolfe
February 18, 2015 5:08 am

Me, too.
Mr. Eschenbach has already done a lot of work for us–which I’m grateful for–but similar plots showing absolute humidity would have been interesting from the greenhouse-gas perspective.

Eric Sincere
Reply to  Joe Born
February 19, 2015 9:55 am

Bingo! +1

george e. smith
Reply to  Willis Eschenbach
February 18, 2015 1:11 pm

Well for me Willis, one of the most interesting tidbits of information, seen prominently in your figs 1,2,3, and clearly non local as evidenced in fig 1, is that the diurnal Temperature cycle isn’t even remotely sinusoidal in shape.
The daily rapid rise in the SST followed by a much slower decay, demonstrates the clear presence of at least a second harmonic frequency component, with a 12 hour period, as well as the 24 hour periodicity.
Consequently any daily reporting of Temperature on a max / min basis or any other twice a day sampling, is a clear violation of the Nyquist sampling theorem, by at least a factor of two.
That means that any reconstruction of the temporal continuous Temperature function, will contain aliasing errors with spectrum components that fold all the way back to zero frequency. Now protestations that a reconstruction of the continuous function is not being sought, and that the samples are only used for an average value, are quite hollow, because that average value, is in fact the zero frequency component of the continuous function and the at least 2 x under sampling means that it is corrupted by aliasing noise.
Given that 70% of the earth surface is water or oceans, it is not comforting to know that the data obtained from twice daily ocean locations, is already rubbish, as far as determining global mean Temperatures. Too bad that the spatial sampling is even less valid.
These buoys of course give a better set of diurnal Temperatures, and satellite scanning improves the spatial sampling, but that doesn’t help all of the data going back to 1850 which purports to be what was real back then, and against which modern data is measured.
I wonder how the fishing is around any of those equatorial buoys ??
g and thanx for another interesting post.

Reply to  george e. smith
February 18, 2015 5:04 pm

George E. Smith
OK. So the daily temperature is not a sine wave: I will definitely agree, but it is interesting that it is not even a smooth single peak, single drop curve either. (At least not in the tropics, which are 58% of the earth’s surface, and are 58% of the earth’s radiating a surface area – an radiating surface area both hotter the rest the planet and larger than the rest of the planet.)
Thus: Is the 24-hour surface is radiating all 24 hours, but the “hot peak” is a longer, multi-headed hydra of several local peaks, then does that not increase total surface radiation heat loss over the course of a single much greater?
the best the school of contemporary CAGW religion can come up with is +3.0 watts/m^2 average after a forced doubling of CO2 AND an exaggerated water vapor feedback. A longer hotter mid-tropic day would radiate all of the excess away, would it not?

Reply to  Willis Eschenbach
February 18, 2015 5:14 pm

George. You have commented on something I have thought for years. Using average of Tmax and Tmin most likely results in too high a temperature compared to the “mean” but that probably changes with latitude.
Basically, it seems, we really don’t know.
Having plotted a number of station Tmax, min, average, I have very little faith in the meaningfulness of the”average” temperature. Tav isn’t a very good representation in a lot if areas. (IMHO)
Great post by Willis. I assume confirmation bias must be endemic in academia. Why can Wilis find “data” when the “experts” use expected results.
Thanks Willis.

george e. smith
Reply to  Willis Eschenbach
February 19, 2015 11:03 am

For RACook,
RA, my entire point is that the common twice per day station Temperature sampling, is inadequate for its stated purpose; to determine a global mean number.
For the non communications engineers, the “Nyquist Sampling Theorem” upon which rests the operability of ALL sampled data systems, including ALL modern communications networks, says essentially :
“””” A continuous ‘band limited’ function can be represented (exactly) by a set of instantaneous sampled values of that function, provided the samples are no further apart that half the period of the highest frequency component present in the continuous function signal. “””””
By “band limited” is meant that the frequency spectrum of the function contains NO components having a frequency higher than some value (B), the band limit.
So a signal containing signal variations up to no more than one MHz can be exactly represented by instantaneous values (zero width) of the signal taken at least every 500 nanoseconds, or if you wish at a 2 MHz frequency rate. They don’t have to be uniformly spaced, but they can’t be more than 500 ns between samples.
Then the entire original continuous function can (in principle) be completely recovered from that set of instantaneous samples.
In modern communications systems, all that empty space between those samples, can be occupied with the instantaneous samples of OTHER signals, and they can all be unscrambled and recovered to send to the intended recipient.
Now if a purportedly band limited signal (bandwidth (B)) is sampled at a sample rate 2B, but there is actually information present at a frequency B + b which is “out of band”, it will be found on reconstruction, that the recovered signal, now contains information at a frequency of B – b which is clearly now an “in-band” noise component; called “aliasing ” noise.
Since it is now in band, it can not be removed by any process, without also removing any real original signals that had an in band frequency of B – b.
So if the out of band component is at a frequency of B + B, or 2B, then the aliased noise in the recovered signal has a frequency of B – B, which is zero, and that is the DC value of the signal or average value if you wish.
So even if there is no intention of recovering the original continuous signal, if you only sample at HALF of the minimum Nyquist rate (2B), then you cannot even calculate the AVERAGE value of your samples correctly because the noise spectrum now extends all the way to DC.
So for our daily diurnal Temperature cycle, the fundamental frequency would seem to be 24 hours period. If there is NO signal information at any frequency than one cycle per day, that means the signal must be a 24 hour period sine wave, and two samples per day at 12 hour intervals will suffice.
But as is clear from Willis’ graphs, the saw toothy shape of the SST diurnal Temperature, is clear indication of the presence of a second harmonic component, which is one cycle per 12 hours, and you would need to sample at six hour intervals to correctly get that information.
So the bulk of the surface reporting stations that so far as I know, just give a daily min max or two samples per day, you cannot use those two samples to get the correct AVERAGE temperature for that day, because the signal is NOT BAND LIMITED to one cycle per 24 hours.
And when you consider the SPATIAL sampling of the global Temperature, well you have cause to totally freak out.
Hansen’s one measurement per 1200 km is grossly under sampled, and there is no way in hell, you can obtain a global average Temperature from such garbage data.
Now Willis may have had some special interest in the specific shape of those graphs; he usually does.
But my only comment was related to the fact that they clearly are not any one cycle per 24 hours band limited signals.
And the more complicated shapes that RAC refers to suggest that there is a heck of a lot more high frequency out of band information than just the second harmonic.
There is a recent paper that I read in either Physics today, or more likely Optics and Photonics News, about a controversial type of super resolution optical system, that purports to be able to resolve optical images beyond the wavelength dependent classical resolution limit, or if you will, out of band signal information.
Other readers have pooh poohed the idea, but the authors stick to their guns, and claim it works. …. BUT … They did not claim to be able to COMPLETELY RECOVER the out of band super resolution signal, which Nyquist says you cannot do.
All they claimed, was the ability to “obtain some information about the out of band components.” Well at least that is how I interpret the donnybrook. And maybe that is correct, and maybe the author did not express himself very well in his response to his critics. I decided to not get into it.

David Riser
Reply to  Willis Eschenbach
February 20, 2015 12:06 am

Yes and Yes, anyone who has spent a significant amount of time measuring hourly temperatures in a single place knows without a doubt that min/max is not a valid sample for average temperature. Having taken hourly temperature measurements in many different places over periods of years, each area, in addition to having a somewhat different average day, has a seasonal component as well.
And yes the fishing around those buoys is very good.

February 18, 2015 4:15 am

The link to the abstract shows that this is a 20 year old paper. Is someone trying to revive Ram’s idea of ‘super GHE’?

Inamdar, AK, Ramanathan V. 1994. Physics of greenhouse effect and convection in warm oceans. Journal of Climate. 7:715-731.

Gras Albert
February 18, 2015 4:28 am

However, even in a fully developed cumulus state, there is not continuous cloud cover. The cumulus clouds can be thought of as flags, each one marking an area where there is an upwelling column of air. However, in between the upwelling air columns and their respective clouds, perforce there must be larger areas of slowly downwelling air

I have 4 decades (several thousand hours) of practical experimentation & observation of the lower atmosphere physics associated with thermals and their associated cumulus clouds. I’m not unique, there are thousands like me across the globe, they’re called glider pilots.
Cumulus clouds are the visible tops of the invisible fountains of air known as thermals. They can be any size from 100m to a kilometer in diameter and a few hundred feet to 10,000ft+ in depth.
Gliders today are equipped with sensitive barometric instruments that can measure vertical movement of the airmass very finely, to as little as a few feet per minute. They are also equipped with data loggers which record, not only a GPS derived location and groundspeed but also the airspeed and altitude thus enabling post flight analysis of the airmass through which the aircraft traveled.
There are literally thousands of flights of duration of up to 10 hours and distances of up to 1500km flown every year, the flight logs of these flights are very frequently available for download and analysis.
Some observations from my personal experience and analysis
In the absence of the special case of cloud streets, the airmass between thermals is frequently neutral, that is as much vertical movement up as down, however, the rate of that movement is a small fraction of that associated with thermals.
A thermal very frequently has a band of strong sinking air, comparable in rate, around the outside of the rising core, the best visualisation is perhaps that of a doughnut in which the air in the centre of the doughnut is rising and the air on outside is sinking. Sometimes the whole doughnut persists from ground level to cumulus, more often the doughnut ascends from ground level to cloudbase (condensation level) at a rate which is small fraction of that in its core.
Both of the above observations apply even when there are no cumulus, i.e. blue thermals, when the air mass is too dry or an inversion prevents the thermal top from reaching the condensation level. and in tipping point phenomena such as thunderstorms where the downdrafts are equally as strong as the updrafts.
I suggest that the primary mechanism for atmospheric pressure regulation in a thermal airmass is the localised descending air associated with the equally localised rising air typically marked by cumulus, not sinking air between thermals.

Joe Born
Reply to  Gras Albert
February 18, 2015 5:05 am

Thank you for those observations. Anecdotal, yes, but compelling as to the localized decent.

A C Osborn
Reply to  Gras Albert
February 18, 2015 6:41 am

What you describe is for all intents and purposes a Pond Fountain with “Bell” nozzle on the top.

Reply to  Gras Albert
February 18, 2015 6:51 am

the best visualisation is perhaps that of a doughnut

We found the same from years of sailing in the tropics. The area of descending air is localized around the thunderstorm. As the rain from the storm cloud passes on the ocean you often get quite a powerful, cold and dry air descending. Very much like standing under an enormous air-conditioner. Very refreshing compared to the sticky, humid air ahead of the storm. The descending air pushes outward on the ocean and is often quite strong that you can see the effects plainly on the water as large dark streaks, sometimes kicking up spray and froth. Because the flow is downward it is typically useless for sailing, but the turbulence can push the boat around quite strongly. Which is always something, the wind pushing 15 tons around like a toy.

Bill Murphy
Reply to  Gras Albert
February 18, 2015 11:35 am

Mostly agree based on my own (anecdotal) 20k++ hours boring holes in the lower/mid troposphere, including a few hundred in sailplanes. Only difference I have is noting that the pattern can change somewhat when a thermal grows beyond the small/medium CU stage to a large CB or full blown thunderstorm.
The FAA data on microbursts for a more scientific view is here: http://lessonslearned.faa.gov/Eastern66/METR4350-microbursts.pdf

Reply to  Gras Albert
February 19, 2015 2:07 pm

Spot on. The propensity of “climate scientists”–academic or self-taught–to indulge in off-base explanations/interpretations of complex geophysical phenomena is enormous. It requires far more than a cursory acquaintance with data and an active imagination to comprehend how nature actually operates. It requires hands-on field experience and an incisive analytic mind. Sadly, the real-world experience of those that dominate the climate debate too often fits in a thimble–with plenty of room left over for their modesty.

Reply to  1sky1
February 19, 2015 2:17 pm


February 18, 2015 4:43 am

“There is kind of a subtle oddity in the daily variations.”
Coincidently, it follows the pattern in the Earth’s Magnetic Field Total Intensity longitudinal change (inverse correlation), most likely irrelevant.
Map: http://www.ngdc.noaa.gov/geomag/WMM/data/WMM2015/WMM2015_F_MERC.pdf
Data: http://www.ngdc.noaa.gov/geomag-web/?model=igrf#igrfwmm

Reply to  vukcevic
February 18, 2015 6:30 am

“There is kind of a subtle oddity in the daily variations.”
Coincidently, it follows the pattern in the Earth’s Magnetic Field Total Intensity longitudinal change (inverse correlation), most likely irrelevant.
Hello vukcevic.
In my opinion, any correlation, either inverse or not, in it’s own merit it is never irrelevant.
To me a correlation means a possibility of connection between the “entities” correlated .
Stronger and more certain the correlation more likely the possibility of that connection and less likely the possibility of just due to some coincidence.
Definitely worth of investigation and a further research in such cases.
Some times a correlation ends up to be (considered) irrelevant due to the very premature jump on conclusion that it definitely means influence or causation between “entities” behavior and connection or because no any such found there.
Considering this particular correlation that you mention, in its own merit it may or may not be irrelevant to climate.
Please do understand I am not saying or claiming that it is irrelevant, only saying that the possibility of its irrelevance exist.
Again the irrelevance exist, as far as I can tell, only on the point of the overestimating exaggerating or even when dismissing or underestimating the value of that correlation.
So a correlation is irrelevant in a particular given issue or matter (like climate change) while no value found in it in regard to such as, or while that value exist but overinflated.
Said all this, my take in this particular correlation as shown through the evidence you bring and considering further other evidence I have come across here at WUWT concerning the same, is that it seems to be relevant enough for consideration and worth of a scientific investigation, ……..not at all irrelevant as it stands at the moment, …………… without prematurely jumping on conclusions so to speak.

Reply to  whiten
February 18, 2015 9:07 am

Hi whiten
I get myself often in ‘hot water’ so to speak, for bringing such things to this blog, but curiosity often gets better of me, and when I get across something interesting, can’t see much point of leaving it on the pc’s hard drive to forgotten for ever.

Reply to  vukcevic
February 18, 2015 6:55 am

if the magnetic field loop westward is a co-incidence it would appear to be a long odds co-incidence.

Reply to  ferdberple
February 18, 2015 9:08 am

Indeed, it is very long odds. Some bright young spark may find out more. Above my pay grade, however there may be two possibilities her:
– Svensmark: weaker field more energetic GCR, high altitude condensation, atmospheric transparency, absorption, albedo, etc.
– Ionospheric currents induction intensity is a function of Earth’s field strength.
NASA: http://www.nasa.gov/centers/goddard/images/content/154188main_plasma_bands_lgweb.jpg
Dotted white lines mark regions where rising tides of hot air indirectly create the bright, dense zones in the bands.
Three of the bright plasma pairs are areas with lots of thunderstorm activity, in this case were located over Africa, Indonesia and costal region of South America.
“The single pair of bright zones over the Pacific Ocean that is not associated with strong thunderstorm activity shows the disruption is propagating around the Earth”

Reply to  ferdberple
February 18, 2015 9:47 am

Enter your comment here…http://www.vukcevic.talktalk.net/NOAA-info.gif
I’ll am already in Mr. Tisdale’s bad book

Reply to  vukcevic
February 18, 2015 2:53 pm

I’d be surprised if that weren’t the case as water is diamagnetic.

Reply to  looncraz
February 19, 2015 3:21 am

Apparent change in saline water’s flow rate due to magnetic field at three concentrations.

Reply to  looncraz
February 19, 2015 12:11 pm

Spread that effect over an entire ocean (with its somewhat variable salinity & alkalinity) and I think it’s clear to see how a magnet the size of the planet can change where water wants to flow when other factors aren’t utterly dominating (below a certain depth, for instance, winds don’t matter – and this effect would modify the result of the changing gravitational pull from the moon, et. al.).
It would be weak, for sure, but it must be present.

February 18, 2015 4:51 am

You are right to dismiss Ramanathan’s fake physics. Firstly, he is in the vanguard of those claiming atmospheric radiant emittance, detected by pyrgeometers, is a real energy flux when it is a potential energy term. Secondly, he fails to understand that the real atmosphere has just a quarter of the humidity that the equilibrium Clausus – Clapeyron equation would give, and it is due to the water cycle.
Increase ‘back radiation’ and net surface IR flux decreases. Thus if it suddenly becomes more humid, net radiant heat transfer is atmosphere to sea surface so it heats up until you get a new evaporative equilibrium, more clouds. Clouds rain harder, reducing humidity, the ocean surface cools. This is Le Chatelier’s principle writ large, an astoundingly stable control system. These people have for 40 years used a puerile view of heat transfer, radiative and IR physics to impose their pseudoscience.

Reply to  AlecM
February 18, 2015 10:32 am

You are correct, but everyone seems to be forgetting that energy transferred into the atmosphere does work expanding the atmosphere which results in cooling the atmosphere. Moist air is also less dense than dry air which also expands the atmosphere. This cooling, Boyle’s Law, is where the extra radiation goes.
Of course it just means that the atmosphere is an energy pump transferring the energy to the poles where the air is compressed, heated, and the energy radiates away.

February 18, 2015 4:54 am

Beautifully and logically argued. Thanks for the insight, Willis!

February 18, 2015 5:01 am

“In any case, it would seem to falsify the idea of a “super greenhouse effect” that is driven by relative humidity as Dr. Ramanathan claimed.”
He didn’t
“The cause of this super greenhouse effect at the surface is the rapid increase in the lower-troposphere humidity with SST”
And he is right of course

Reply to  lgl
February 18, 2015 5:18 am

Seems to me that those two graphs don’t really say what you think they say. The local downwelling radiation depends on both atmospheric composition AND the local atmospheric temperature near the surface. Where the local temperature is higher, even with constant atmospheric composition, the downwelling surface radiation must increase. So the plot of downwelling radiation confounds the temperature and humidity (atmospheric composition) effects. You would need to separately account for the influence of near surface atmospheric temperature to draw conclusions about how atmospheric composition influences downwelling radiation.

Joe Born
Reply to  stevefitzpatrick
February 18, 2015 5:27 am

“Where the local temperature is higher, even with constant atmospheric composition, the downwelling surface radiation must increase. So the plot of downwelling radiation confounds the temperature and humidity (atmospheric composition) effects.”
True enough. But why wouldn’t you expect, if there is indeed a greenhouse effect, that more water vapor per unit volume would increase downwelling radiation? Is there some reason to doubt that?

Reply to  stevefitzpatrick
February 18, 2015 5:37 am

There is no reason to doubt some effect. But those two graphics don’t tell you what the magnitude of the water vapor (alone) effect is…. the very strong temperature effect is confounded with the water vapor effect.

Joe Born
Reply to  stevefitzpatrick
February 18, 2015 7:31 am

Ah, maybe I see what you mean. Yes, you’re saying, increased temperature does on average increase absolute humidity if not relative humidity. And that by itself does (loosely speaking) increase the “resistance” that radiation from the surface encounters in reaching outer space. But that effect may be accompanied by countervailing factors, such as albedo increases and enhanced latent-heat transport through much of that increased optical distance. Therefore, those maps tell us nothing about the size or sign of the net feedback.
It’s part of the familiar discussion. Everything else being equal, increased carbon-dioxide concentration raises the surface temperature required to return into space the energy the earth receives from space. In turn, that increase would raise the absolute humidity, which, absent further effects (such as a slightly reduced lapse rate) would increase the required surface temperature even further. You don’t question that; you at least provisionally accept that these effects constitute positive feedback (or, from the outer-loop point of view, less-negative feedback). What you’re pointing out, though, is that the maps don’t separate such positive-feedback effects from attendant negative-feedback effects, such as (arguably) albedo and more-efficient latent-heat-transport bypassing of the radiative path.
More generally, I think you may be saying, those maps don’t tell us whether the surface-temperature increase required by increased carbon-dioxide concentration is greater or less than it would be in the absence of water-vapor and other knock-on effects.

Reply to  stevefitzpatrick
February 18, 2015 8:24 am

Yes, but if you look at a temperature map you will see the correlation is between LW and vapor, not between LW and temperature. Compare Sahara with the ocean around Indonesia for instance.

Steve Fitzpatrick
Reply to  stevefitzpatrick
February 18, 2015 10:11 am

So to get a more complete picture of the humidity influence you need to show the surface temperature graphic as well, right? You didn’t show that. You appear to claim that the two graphics support: ““The cause of this super greenhouse effect at the surface is the rapid increase in the lower-troposphere humidity with SST”. They sure don’t do that very well.
What you showed (down-welling radiation and water vapor), ignores the influence of local atmospheric temperature on down-welling radiation…. which has to be very large. I am not saying that there is no water vapor effect on down-welling radiation (there has to be!), I am saying the graphics you showed don’t demonstrate that clearly. In addition, the graphics are annual means, which makes a lot more sense over the tropical ocean, with little seasonal temperature change, than it does over the Sahara….. where winter and summer temperatures (and down welling radiation!) are very different. The Sahara is quite pleasant this time of year… not so in July.

Reply to  stevefitzpatrick
February 18, 2015 10:45 am

Downwelling long wave radiation causes surface evaporation and cooling, it is not absorbed below the surface.

Reply to  stevefitzpatrick
February 18, 2015 11:29 am

OK, found a temp map with better resolution than the JMA map
So clearly, “The cause of this super greenhouse effect at the surface is the rapid increase in the lower-troposphere humidity with SST”. But it’s a feedback loop so one can also say the cause of the high SST is the super greenhouse effect.

Reply to  lgl
February 18, 2015 5:27 am

Your charts are drawn at a planetary scale and show that the areas with increased precipitable water coincide with the ascending branches of the Hadley cells which circle the Earth near the equator, and are the drivers for the general circulation of the Earth’s atmosphere.
Willis, OTOH, is addressing the mesoscale convection system (MCS), which feature updrafts of warm moist air and downdrafts of relatively drier cooler air.
Both are valid observations, depending on scale.
I didn’t read the paper, so was Ramanathan merely “re-explaining” Hadley cell circulation (moonsoon troughs etc)? Or was he addressing mesoscale convection circulation?

Reply to  Johanus
February 18, 2015 6:24 am

Also, longwave radiation shown is strongest at the equator because the radiance is proportional to the incidence of solar rays (Lambert’s Cosine Law).
There is a curious decrease in longwave over Africa and Brazil. Can be seen more clearly in this Ceres imagery (which also shows a similar decrease over Indonesia) Why is that?
Could it be photosynthesis, which is somehow (waving my hands) ‘sequestering’ the radiation and storing it in plants and releasing it as CO2?

Reply to  Johanus
February 18, 2015 7:12 am

February 18, 2015 at 6:24 am

Also, longwave radiation shown is strongest at the equator because the radiance is proportional to the incidence of solar rays (Lambert’s Cosine Law).
There is a curious decrease in longwave over Africa and Brazil. Can be seen more clearly in this Ceres imagery (which also shows a similar decrease over Indonesia) Why is that?

Interesting. The CERES satellite imaery definitely shows significant and precise correlation between “deciduous and evergreen trees (Canada, mountain and hilly North America) and and taiga forests (Canada and western Europe and Russia/Siberia) and farmland (US, Canada, WE, and north India) and jungle (Congo, sub-sahara Africa, Malaysia and all far east island (between island ??), and the Amazon basin. Less vegetation (south Brazil highlands for example, SW US (CA, AZ, NM, TX) show up as well.
Yes, it is interesting.

Reply to  Johanus
February 18, 2015 7:42 am

The decrease in longwave over Africa and Brazil and Indonesia is caused by all the high clouds there.

Reply to  Johanus
February 18, 2015 8:33 am

“… caused by all the high clouds there”
Hmm. You’re showing us “high-level cloud” plots from the JRA-25 Atlas which is a 25-year reanalysis (i.e. modeled global fill-ins).
The “high-level” cloud plots do partially coincide with the ‘curious’ Ceres negative long-wave anomalies, but also extend over the oceans. So why don’t these oceanic high-level clouds decrease the surface long-wave?
Why not show us the “low-level” clouds, where most of the dynamic weather takes place?

Reply to  lgl
February 18, 2015 7:00 am

And he is right of course

That doesn’t follow. What your graphs show is that rain increases with cloudiness. Pretty much any child of 5 could tell you that.

Reply to  ferdberple
February 18, 2015 7:47 am

The map shows vapor, not rain.

Reply to  ferdberple
February 18, 2015 12:59 pm

Actually, according to the JRA-25 specs, the precipitable water value is computed from microwave (SSM/I) sensors, which can distinguish the different phases of water, e.g. ice crystals, so is more informative than the IR water vapor (WV) signal (6 microns)
Here’s METEOSAT’s WV loop over Africa. Note the westward motion of the “monsoon trough” at the equator which accounts for most of the WV seen here. The dark areas represent the strongest IR signals at 6 microns, i.e. from the surface radiating into space (i.e. little or no absorption, so no WV). The grey and white areas represent areas of strongest absorption of the upwelling IR by WV, with white indicating nearly total absorption by WV. (So think of it as a kind photographic ‘negative’ image).
So you can actually see the Greenhouse Effect in action, at least for water vapor. And forecasters would be crippled without access to this kind of water vapor imagery. WV has a tremendous impact on weather (and hence) climate.
Would it be possible to see CO2 similarly “in action”, passively, at 4 or 12 microns? Apparently not. None of the weather satellites have channel for this, so apparently it’s too tenuous to render into any useful images, implying that it doesn’t have a great impact on weather or climate, like WV does.
Please correct me if I’m wrong about this. I think we would all love to see a live, passively received “CO2 vapor” loop. OCO2, the recently launched CO2 observatory uses a much more complicated method, involving transmission spectroscopy of reflected short-wave sunlight, to detect and image atmospheric CO2.

Reply to  ferdberple
February 18, 2015 1:01 pm

… and here’s the METEOSAT WV/IR loop that I forgot to insert:

Stephen Richards
Reply to  lgl
February 18, 2015 11:41 am


Reply to  lgl
February 20, 2015 4:46 am

The cause of this super greenhouse effect at the surface is the rapid increase in the lower-troposphere humidity with SST.

It appears that landmasses are blocking the “natural” cycles of global humidity and temperature. This calls for a geo-engineering solution to remove those dangerous landmasses. After all, it would probably be easier than eliminating the use of fossil fuels.

February 18, 2015 5:06 am

Very nice analysis. It looks to me like the daily variation in air temperature and the daily variation in relative humidity could be used to calculate the variation in absolute humidity at the surface (using Clausius-Clapyron, ~7% increase in water vapor pressure at saturation per degree C increase in temperature). It is only the absolute humidity level which influences radiative transfer. I suspect you will find very little change in absolute humidity near the surface…. which would appear to contradict the proposed “super-greenhouse” effect.

February 18, 2015 5:35 am

One must assume a greenhouse effect exists before a super greenhouse effect can be relevant. If the greenhouse effect is zero, super sizing it will still leave it at zero.
One of the many problems with greenhouse earth ideas is that of heating occurring only from the surface up. Energy is absorbed at every level in the atmosphere though. In fact the most energetic radiation will be absorbed at the boundary of space and less and less energy will be absorbed per molecule as one decends towards the surface.
Our surface is simply an area where the remainder of suns energy is absorbed over a thinner space due to liquid and solids being denser than gasses. Hot air rises and cools, not because of massive energy loss by individual molecules, but because the total number of molecules in any given volume drops with altitude.
The properties of radiative absorbtion in molecules become irrelevant with convection and conduction constantly changing molecular wavelengths through collision.

February 18, 2015 5:49 am

The thing that is most interesting (and surprising) to me is that the assumption of “constant relative humidity” over the ocean appears to be refuted by the data. That is, as you go from the cooler Eastern Pacific to the much warmer (about 5C) Western Pacific, the average relative humidity falls by about 12% (if I am reading the graphs correctly). So instead of a rise in absolute water vapor concentration of ~35-40% across the tropical Pacific, which you would expect at constant relative humidity, the rise in absolute humidity is closer to 23-27%. This really does surprise me.

Kelvin Vaughan
February 18, 2015 5:55 am

When i was a boy in London, on a hot sticky day everyone would say ” what we need now is a nice thunderstorm to cool things down.

A C Osborn
Reply to  Kelvin Vaughan
February 18, 2015 6:45 am

And they usually did.

Gary Pearse
February 18, 2015 6:20 am

Willis, a fine piece of work and a good learning exercise for me. Looking at any individual buoy, there is an immediate jump in RH right after the sun goes DOWN and the precipitous drop after it rises. I say to myself, well, air cools and then warms and even if moisture were unchanged, RH would go up and back down. This makes sense to me. The real surprise is when you look at the whole string of buoys and see that the warmest part of the ocean has the lower RH. Now that is a revelation in itself as well as an insight into the myopic, simplistic way climate is studied by many of its experts. They go into the office clutching their Clausius-Clapeyrons, instead of going into the field where they will find C-C is of little use in a real dynamic situation where variables not in the equation abound.

February 18, 2015 6:22 am

Nice one Willis, Thanks. I spent three years in Singapore in the 1960’s and remember the ‘heat and the humidity’. The interesting thing was the maximum daytime temperature never seemed to be much more than 30C all year round, and the night time temperatures never seemed to get cold. I’ve been using that as an explanation for water vapour molecules in the air have a cooling effect when the sun is shinning and a blanket effect (slow temperature drop) at night. Why people think more water vapour will make things hotter beats me. I’ve experience this ‘blanket effect’ from low cloud where I now live in south Wales.

Reply to  Richard111
February 18, 2015 7:19 am

I spent three years in Singapore in the 1960’s and remember the ‘heat and the humidity’.

We spent quite awhile over the years anchored in Singapore, anchored off the Police station on the Malay side at Johor. Convenient place to bring the dinghy ashore, and for security nothing beats anchoring at a police station. Absolutely necessary in the more remote areas where security can be a serious problem. When you come ashore strike up a conversation with the duty watch, asking permission, and you are good to go.
I always thought of clouds as my friends in SE Asia. During the day the sun can be brutal, especially if you have fair skin and are prone to sunburn. Clouds are most common in summer, in the rainy season, where they take the heat off the day. Winter in the tropics is the dry season, where sunburn can be a real problem. Spring and fall are by far the hottest part of the year, where winds are often light during the switch between the on-shore and off-shore monsoon.

Reply to  ferdberple
February 18, 2015 7:26 am

ps: the reason you ask the duty watch permission is not to get permission, because it is always granted. it is to show respect so that they will take an interest in your boat and watch it while you are away. same reason you ask the toughs on the beach if it is OK to leave your dinghy. otherwise, it might go missing if you slink past without talking to the locals.

February 18, 2015 6:38 am

Water evaporates into air because the air is drier, not necessarily because it is warmer. Warm air will hold more water vapor, but it is relative humidity that drives the evaporation, not temperature.

Reply to  nickreality65
February 18, 2015 7:08 am

Quite so.
It is the low RH of adiabatically warmed descending dry air that determines how much evaporation there can be.
The amount of evaporation is therefore related to the height from which the descending air column has fallen and that is dependent on the power of the earlier uplift.
A more powerful uplift results in more warming on the descent and thus a lower RH when the descending air returns to the surface.
Global evaporation is controlled by adiabatic uplift and descent via changing RH levels as much as by surface temperature.
If the surface temperature rises then more evaporation occurs but only if RH allows.
Any increase in RH from more evaporation in one location gives more convective uplift because water vapour is lighter than air. The higher extent of the uplift in that location then causes a decrease in RH on the next (longer) descent in another location and so global RH remains stable.
Willis’s thunderstorm / emergent phenomena concept is correct but needs to be scaled to the entire planetary atmosphere rather than just acting in the tropics and the active mechanism is not net radiative fluxes as Willis avers but rather atmospheric mass doing work against gravity (cooling) in uplift and with gravity (warming) in descent.

February 18, 2015 6:44 am

Willis said:
“But in the much larger area in between the thunderstorms, you have dry descending air. This is air from which the water has been stripped by the thunderstorm through a combination of condensation and freezing.”
For the global atmosphere as a whole there is as much descending air as there is ascending air and the descending air warms adiabatically at the dry adiabatic lapse rate (DALR) as it descends. That is not deniable.
It is that warming of descending air that keeps the surface warmer than it otherwise would be without an atmosphere.
Being dry, that warming descending air is clear of cloud and so lets solar energy in, just like a glass greenhouse roof.
That warming, descending air also reduces upward convection from the surface just as a greenhouse roof prevents convection.
The net result is a surface temperature rise above S-B for the planet as a whole.
The greenhouse effect is nothing to do with radiative fluxes. The observed radiative fluxes are a mere consequence of the vertical temperature profile created by adiabatic uplift and descent doing work against or with gravity.

DD More
February 18, 2015 6:46 am

Wills, let’s put some numbers against his argument of “the excess longwave energy emitted ” is the main driver.
So Sublimation of water is 2,830,000 J/kg. http://www.theweatherprediction.com/habyhints2/524/
To evaporate 1 m^3 of water with sea water specific volume @ 15 oC at 0.001009 m^3/kg for each m^3 there is an exchange of
=> 2,830,000(J/kg)/0.001009(m^3/kg) = 2,800,000,000 J/m^3
And since most of this energy is taken from the nearby sea water – it will cool
Specific Heat Sea Water = 4,009 J/kg oC 2,830,000/4,009 = 705 or 705 kg by 1- C
60 sec * 60 min * 24 hours * 365.25 days = 31,557,600 sec/yr
Fig 6- Radiative forcing for different anthropogenic and natural perturbations from 2005 relative to 1750. Re-printed from IPCC 2007. http://www.mathaware.org/mam/09/essays/Radiative_balance.pdf
Shows Radiative forcing of CO2 = 1.66 W/m^2 CH4 = 0.48 W/m^2 N2O = 0.16 W/m^2 and Halocarbons = 0.34 W/m^2. Total Long- lived greenhouse gases = 2.64 W/m^2 for their changes from 1750 to 2005.
Joule = Watt * sec
All this leads to => 2.64 W/m^2 * 31,557,600 sec/yr = 83,312,000 J/m^2 in a year.
Compare to => 2,256,600 * 1000/ (J/KJ)/m^3 = 2,256,600,000 J/m^3 to evaporate the water
–> 83,312,000 J/m^2/2,800,000,000 J/m^3 = .03 m = or 3 cm and if open ocean/total area is 65% then 3/ .65 = 4.6 cm (2.54 to the inch) of extra ocean evaporation would eat up all the extra LW radiation from Long-lived GHG from 1750 to 2005 each year.
In comparision the total annual ocean evaporation rate = 140 CM.
from http://www.eolss.net/sample-chapters/c07/e2-02-03-02.pdf
His ideas of the drivers do not add up correctly.

Joe Born
Reply to  DD More
February 18, 2015 8:13 am

Could you flesh out the logical step between your last two paragraphs a little?
I read your comment to say that the putative forcing increase over the industrial era is enough to support a 3 cm / 140 cm = 2% increase in rain. Presumably such a rain increase would on average reduce the proportion of the (increased) optical thickness that the surface’s heat energy has to traverse to escape to space: the positive-feedback effect of the optical-thickness increase would to some extent be canceled by the negative effect of that optical thickness’s being partially bypassed.
But how does that refute the proposition that “‘the excess longwave energy emitted’ is the main driver.” Driver of what? With what is that 3 cm being compared? How much of that possible rain increase has actually occurred? Quantitatively, what effect would it have if it did?

Reply to  DD More
February 18, 2015 8:28 am

Thankfully someone else can do math as well. (I’m not being sarcastic) When CAGW makes those kinds of statements that’s the first thing I do, is the math… and that is being generous using their numbers.
GHG (if it works the way they say it does) may not be the only factor warming water. Microwaves at 2054Mhz works really well, decrease the magnetic field a little, and it’s not even affected by cloud cover, zips right through. The really great thing is that the effect at the poles is squared. It can be darn right freezing and still melt ice.
To head off future useless debate by CAGW, they will say that once that heat is released from the latent heat of water vapor, that adds to further warming. Never mind that cooler drier air that gets displaced and pushed down by thunderstorms. (Actually had that conversation that didn’t happen during a thunderstorm) Again the math is pretty easy to do.
The 1% increase in water evaporation is lower than the 3% that I give GHG. Either one, basically background noise.

February 18, 2015 6:54 am

“The real surprise is when you look at the whole string of buoys and see that the warmest part of the ocean has the lower RH.”
No surprise because the warmest SSTs are beneath cloud free skies where incoming sunlight is strongest. Such cloud free skies are a consequence of air descending from above in regions of higher than average surface pressure (descending air) and that descending air is dry with low RH having both warmed adiabatically and having had its moisture wrung out of it during earlier convective uplift elsewhere in regions of lower than average surface pressure (ascending air). That causes lower RH beneath descending air columns (50% of the atmosphere at any given moment).
It takes time for evaporation from the sea surface to raise RH again and during that time the air circulates towards the nearest lower pressure area where the added water vapour is allowed to cause renewed uplift again (water vapour being lighter than air).
All consistent with Willis’s findings as far as I can see.

Gary Pearse
Reply to  Stephen Wilde
February 18, 2015 7:33 am

So you expect the warmest part of the ocean to remain cloudless and with low RH? I think the point is that this causes a build up of moisture and emergent clouds and thunderstorms. I’ll grant you if you simply heat up air, the RH will go down in the short run – it does in the Sahara, but when there is no shortage of water…It might be my poor description of a dynamic situation in my earlier post, because I thoroughly agree it’s consistent with Willis’s findings.

Reply to  Gary Pearse
February 18, 2015 9:04 am

I would expect the warmest areas to remain cloudless with low RH as long as descending air is dominant.
Any moisture that builds up flows outwards towards areas of lower surface pressure and it is there (where ascending air becomes dominant) that the emergent phenomena described by Willis occur.

D.J. Hawkins
Reply to  Gary Pearse
February 18, 2015 4:02 pm

The problem is that the maps above show the (high level) cloudiest areas are the warmest.

February 18, 2015 7:06 am

Figure 8 blows the “super greenhouse” nonsense out the window. If there was a ‘super greenhouse’ effect then RH should be greatest where the water is warmest. Instead we find the opposite is true.
“super greenhouse” = super fail.

David Chappell
February 18, 2015 7:13 am

Dr Ramanathan says “…a combination of increase in humidity in the entire column and increase in the lapse rate within the lower troposphere.”
If I recall my aviation meteorology lectures from a long time ago, surely the lapse rate decreases with increasing humidity?

Joe Born
Reply to  David Chappell
February 18, 2015 7:23 am

I had trouble understanding that part, too. Surely he meant something other than what you and I read that passage to say, but I can’t figure out what that might have been.

February 18, 2015 7:15 am

For the purposes of discussing the greenhouse effect of water vapor, I do not think that relative humidity is the correct measure, although it is closer to what we feel as mugginess. Wouldn’t the partial pressure of water vapor (or an equivalent, like mass density) be the correct measure? If so, then at noon there are 22g of water vapor per cubic meter of air at 165E, and 18.7g/m3 at 95W. Thus at noon the absolute humidity is higher over the warmer ocean, even when the relative humidity is lower. At 5PM, where the curves separate the most, there is still 22.0g/m3 at 165E, and 18.6g/m3 at 95W. At midnight, it is 22.0g/m3 at 165E and 18.8g/m3 at 95W.
So it seems that the absolute amount of water in the air is essentially constant at a given location on the equator, but higher where it is warmer, making for a “steam engine” that more efficiently pumps heat to the top of the troposphere, and lowering diurnal variation in temperature.

Kevin Kilty
Reply to  UnfrozenCavemanMD
February 18, 2015 1:07 pm

Except that the proponent of AGW would simply point out that constant RH, in conjunction with a positive coefficient of saturation value with temperature, implies increasing mixing ratio or absolute humidity.

February 18, 2015 7:17 am

Hello Willis
you say:
But according to Figure 8, the relative humidity in the convective zones of the Pacific varies inversely with sea surface temperature. And this is true both for long-term average sea surface temperature, as well as for the daily average temperature variation.
I can’t say that I have any great conclusions from all of this. However, it does appear that the modelers’ claim of strong water vapor feedback rests on the idea that relative humidity stays constant in the face of warming. If these TAO data findings are correct, and if relative humidity more generally is not constant with respect to temperature, it would seem that this would greatly reduce the amount of purported water vapor feedback …
If in the long-term average sea surface temperatures changes (varies) very little in these convective zones of Pacific how would the variation of relative humidity be significant enough to be considered as other than constant?
If the variation of the average SST very little in the long-term, like from LIA to present, how in the face of a significant warming during all this time, the variation of relative humidity in long-term could be significant enough as to be considered other than a constant?
Probably I got something wrong here and hopefully you may explain it to me if that is not much to ask for.
Please understand I am not trying to imply or claim that the “super greenhouse effect” correct and you wrong, or the other way around.

February 18, 2015 7:32 am

I can’t help but love the term ‘super-greenhouse effect”. The hype never stops. Although super-greenhouse is even a little subdued. That must mean mega-greenhouse or greenhousenado were already taken.

Reply to  logos_wrench
February 18, 2015 8:47 am

Hi logos.
That is the beauty and the whole fun with it.
The hype is actually “killing” AGW.
More hype, more of “supers” and “mega” with the greenhouse effect, bigger the missing heat, bigger the problem with the AGW hypothesis, bigger its problem with reality, more, far more ridiculous the claim that greenhouse effect is or will be a climate changer.

Craig Loehle
February 18, 2015 7:51 am

You have to watch out for those assumptions. That warmer air holds more water is only true for water in a jar. Otherwise, dynamics can change it, as Willis demonstrates. The assumption in GCMs of constant relative humidity is a moronic simplifying assumption of the sort that a modeler might use to get started. It is not a sound basis for building world-changing models. There is lamentably poor data on actual humidity over time.

Reply to  Craig Loehle
February 18, 2015 10:27 am

It’s true for industrial size wet cooling towers and those house top evaporative coolers. Not exactly closed jars.

Reply to  Craig Loehle
February 18, 2015 1:06 pm

Craig, Judith Curry and I had a go around on this which drove me to work through the NCAR CAM3 model documentation before finishing my humidity post for her in 2012. The models do not embed an explicit Clausius-Clapeyron UTrh lapse rate. Well, for sure not CAM3, and per AR4 not the others either. But when run, they all behave as though they did. AR4 WG1 Black box 8.1. AR4’s attempt to show this model result accorded with observation is a massive selection bias cherry pick, which was the real subject of my post and that illustration in my ebook The Arts of Truth.. My hypothesis for how the models actually misfire on this is below. If that hypothesis is correct, then the flaw is inherent and unfixable.

February 18, 2015 7:52 am

These tropical thunderstorms are not only regulating air temperature,they are regulating the concentration of CO2 being pumped out their tops. The regulating processes are evaporation/condensation, freezing/thawing, absorption/extraction, and the vertical changes in their rates. Any detectable “greenhouse effect” from CO2 or water vapor will be lost in the variability of these processes.

richard verney
February 18, 2015 8:02 am

An interesting study.
The real problem with the super greenhouse effect is that there appears to be no effective mechanism whereby LWIR can heat the oceans.
About 60% of all DWLWIR is fully absorbed within just 3 microns. Almost none finds its way past 10 microns.
The only proferred mechanisms mixing the very top of the oceans is wind and waves, and ocean over turning, but these are slow mechanical processes.
Willis, what is the rate (or your best guestimate) of the rate at which wind and waves mixes the very top of the ocean when say local conditions are BF1 or less, BF2 or less, BF 3 or less.
Willis, in the Doldrums how does the action of the wind and waves effectively mix the DWLWIR being absorbed in the top few microns of the ocean?
Willis, you mention ocean overturning, and note that this is a diurnal phenomena. What is the rate (or your best guestimate of the rate) at which ocean overtuning effectively mixes the very top of the ocean (and hence the DWLWIR being absorbed within the first few microns) say between 00:00 to 06:00 hrs, between 06:00 to 12:00 hrs, between 12:00 to 18:00 hrs, and between 18:00 to 24:00hrs?
Can either and/or both of these mechanical processes realistically mix the very top of the ocean (and hence the LWIR absorbed within the top few microns) and sequester the energy absorbed in the top few microns to depth (where volume will disipate that energy) at a rate faster than the energy from LWIR being absorbed in the top few microns would otherwise drive evaporation?
If those slow mechanical mechanisms cannot sequester the energy being absorbed in the top few microns at a rate faster than that energy would otherwise drive evapporation, all that is happening is that DWLWIR goes to drive evaporation and not to heat the ocean

Reply to  richard verney
February 18, 2015 9:07 am

Richard V. How do you think seaweed and plankton and such grow several meters below the surface? What is the ‘heat energy’ in such wavelengths?

Reply to  Richard111
February 18, 2015 11:54 am

UV and visible light get deeper than IR.

richard verney
Reply to  Richard111
February 18, 2015 3:28 pm

It would appear that the oceans are only heated by Solar, and this provides all the energy not only to heat the oceans but also for plankton and other life forms that dependent upon its energy..
Fortunately for us the absorption characteristics of Solar in water is very different to that of LWIR (about 50 to 60% of DWLWIR is fully absorbed within the top few microns and about 90% within the top 10 microns).
Instaed of being almost fully absorbed in the top 10 microns, almost no Solar is absorbed in the top 10 microns of the ocean. Instead, it is absorbed at depth predominantly between 50 cm and 5 metres (about 50% is absorbed within the first 1 metre of the ocean and a further 30% within the next 9 metres), but some will make its way to great depths (depending upon purity) of around 100m. This allows Solar to heat gradually the oceans, rather than boiling them off from top down as would be the case if Solar was absorbed in the same manner as LWIR is absorbed.
See for Solar: comment image
See for LWIR:comment image
But when considering the absorption of DWLWIR, bear in mind that DWLWIR is omni-directional, ie., some of it is intercepting the ocean at a grazing angle of 10 degrees, or less, some at 20 degrees, or less, some at 30 degrees or less etc such that very little is intercepting the oceans perpendicularly; hence the reason why a greater proportion of DWLWIR is fully absorbed in 3 microns than would be the case if it was compiled exclussively of LWIR intercepting at the perpendicular (the plot detailed above is vertical penetration).

Reply to  Richard111
February 20, 2015 8:43 am

“It would appear that the oceans are only heated by Solar”
This is because the radiation from the Sun is a transfer of energy to the ocean AS HEAT [Q]. And an input of heat is what … heats.
A postulated – but ultimately imaginary, purely mathematical – flux of energy from a cooler atmosphere to a warmer ocean surface, like the DWLWIR, is not a transfer of energy as heat. The heat flux (the transfer of energy as heat) between the ocean surface and the atmosphere above it is … UP. The atmosphere is the surface’s COLD reservoir. The surface is the atmosphere’s HOT reservoir. Whence the direction of the heat flow.
So please stop it with this nonsense idea that DWLWIR might heat the ocean or might provoke evaporation (which thermodynamically is an equivalent process, requiring a ‘net’ energy transfer). It couldn’t. Only at the times and in the places where the atmosphere is in fact warmer than the ocean surface. Only THEN this whole discussion about how far down the IR can penetrate becomes relevant …

February 18, 2015 8:21 am

Great analysis. Lends strong observational support to Lindzens adaptive infrared iris hypothesis (BAMS 2001).
AR4 argued strongly for constant Upper Troposphere relative Humidity (UTrH) because that is what the CMIP3 models produced. Their observational evidence was one satellite/ model comparison. Gross selection bias evidenced by dismissing two papers that showed UTrH declined, and ignoring two others reaching that conclusion. Story is in the climate chapter of last book.
Since 2007, a number of papers and studies have come out showing this decline. Specific humidity increases, but not enough for constant UTrH. Documented in essay Humidity ia still Wet. So CMIP3/CMIP5 overstate water vapor feedback; they model a tropical troposphere hotspot that does not observationally exist. Reason is that neither CMIP3 nor CMIP5 can simulate tropical convection cells (Tstorms) due to grid scale computational limitations. See essay Models all the way Down. So have to be parameterized.
CMIP5 parameters were selected to best hindcast 1975-2005 as part of the formal experimental protocol. A period of warming partly from natural variation when model attribution was GHG. So now the pause and the divergence which falsifies the models, and so their high sensitivity, and so CAGW.

Reply to  Rud Istvan
February 18, 2015 10:07 am

“CMIP5 parameters were selected to best hindcast 1975-2005 as part of the formal experimental protocol. A period of warming partly from natural variation when model attribution was GHG. So now the pause and the divergence which falsifies the models, and so their high sensitivity, and so CAGW.”
No. they were not.

Reply to  Rud Istvan
February 18, 2015 11:39 am

Hi Rud.
I am not well informed in this Upper Troposphere relative Humidity or the relative Humidity and its actual play in GCMs.
But the way you have put it in your comment it has sparked some interest and I would like to explore it a bit further especially in the angle you have put it. Especially in regard to the missing predicted tropical troposphere hotspot.
Selecting from your comment above:
“AR4 argued strongly for constant Upper Troposphere relative Humidity (UTrH) because that is what the CMIP3 models produced. Their observational evidence was one satellite/ model comparison.
So CMIP3/CMIP5 overstate water vapor feedback; they model a tropical troposphere hotspot that does not observationally exist.”
Do actually the CMIP3/CMIP5 keep the UTrH as constant (forced to)…. and in the same time are allowed to fluctuate the relative humidity for the Lower Troposphere?
If that the case, then there could be an interesting explanation for the artificial hot spot, especially if the SST-relative Humidity relation is as shown by Willis.
Looking forward for a reply. Thanks.

Reply to  whiten
February 18, 2015 1:50 pm

See my response upthread Craig Loehle. UTrH is not forced, for sure not in Cam3. It is an emergent property. The error has to be in the parameterization. Tropical convection cells (T storms ) can be adequately resolved in weather forecast models with grid scales on the order of <4km (ECMWF is 1.5 km, initialized from a 30 km regional grid and observed regional boundary initial conditions). See essay Models all the way Down for an illustration using an Arizona thunderstorm system.
The finest GCM resolution in CMIP5 is 120km (1.1degree); typical is 2.5 degree which is about 280 km near the equator. GCMs cannot do finer grid scales because of computational constraints. Halving the gird size quadruples,the number of cells, and nearly quadruples,the number of time steps needed. You run out of MIPS. So tropical convection features arenecessarily parameterized to some presumed average for the cell.
Each model/group has different parameterizations. Cam3 is particularly understandable because the design deliberately uncoupled the dynamical core (physics) from the parameterizations. CAM3 parameterized deep convection (tech manual 4.1), condensate and precipitation (tech manual 4.5), dry adiabat adjustment (4.6), cloud fraction (4.7), cloud nature (4.8), and OLR greenhouse effect(4.9). The water vapor parameterization is 4.9.2 starting page 121. Standard absorption/emission stuff for typical frequency ranges. Usubnw is pressure weighted precipitable water (specific humidity) and Tsubp is the absorber (water vapor) weighted path temperature. Relative humidity is a dependent parameter calculated from these, used only to modify aborption/ emission line broadening and line strength. All this for large atmospheric grid cells coupled to a slab ocean model.

Reply to  whiten
February 18, 2015 2:30 pm

Further clarifications. 1. Each model grid cell and time step,is calculated identically; that is the dynamical core part of NCAR CAM3. But each grid cell lat lon and altitude, has to start with unique initial conditions and responds to changes in those when the dynamic core throws its estimate of a time step change in the cell against the cell’s parameters. Tropical convection at the ITCZ is intense; it is very scarce over the Sahara desert.
2. In the previous reply, I went back to the archived documentation to be precise. It is NCAR/TN-464+STR, June 2004. Free on line.
3. The CMIP5 experimental design is decribed by Taylor, Stouffer, and Meehl, originally 2009 with a corrected version 2011. Available free on line. Table 1 summarizes decadal prediction experiments. 1.2 is 30 year hindcasts using RCP4.5 from 2005 (and 1980 and 1960) with an ensemble size of 3 for each start date. It is evident bt comparison that parameterization was chosen to best match 1975-2005. Initial conditions were supposed to be ‘in some way’ oberved within 4 months prior to 1/1/75. The parameter choices (whatever each group did) amount to the model ‘tuning’ Mosher apparently thinks did not happen. Well, CAM3 was not parameterized by immaculate conception.

Reply to  whiten
February 18, 2015 2:46 pm

Whiten, final short comment. It is the specific humidity in the upper troposphere that is significant for the CO2 greenhouse effect. See essay Sensitivy Uncertainty. Lower down rH does appear pretty much to follow the C/C equation. Main way any humidity can get that high is cumulonimbus. Most frequently in the tropics Willis analyses here. I speculate that the reason UTrH is not preserved is that with warming, there is more evap, more WV near surface, and consequently for whatever reasons disporportionately more humidity lowering precipitation from Tstorms. CMIP3 and 5 models underestimate precipitation, by up to half.

Reply to  Rud Istvan
February 18, 2015 2:47 pm

Rud Istvan
February 18, 2015 at 1:50 pm
Hi again.
Thank for the reply.
Sorry for bothering you again.
I actually was not meaning that UTrH is forced on the GCMs when I asked about it.
What I was meaning was if the considered UTrH as a constant was forced instead of being a variable allowed to fluctuate in accordance to the variation of the other parameters related to!?
In another way, you say UTrH (Upper Troposphere relative Humidity), and I say LTrH (Lower Troposphere relative Humidity), does this LTrH make any sense, and if it does is it treated same way by the models with no any strong argument for it to be a constant.
That what I am interested to know, if this has any substance.
I am asking you because clearly I do not have your experience and expertise in this particular matter, and it may take a lot of time to get there for me.
And because is very interesting to me.
For a long time I have been convinced that the GCMs are run under an exaggerated CS so to speak.
But to be fair and honest I been scratching my head for as long too , because even in that case there should not have being so much projected warming if the replication in to the GCMs of atmospheric functioning through all the mechanisms and couplings known and considered was a good and accurate enough replication.
Now thanks to you and Willi too, I can see a possibility that may end that head scratching, so to speak..:)
Please if you can take it up to consideration again and try to clarify this for me, will very much appreciated.

Reply to  whiten
February 18, 2015 5:45 pm

Sure. Surface UTrH is observed to follow C/C over the oceans. Less over land; simple lack of sufficient water. So the question really becomes the rH lapse rate with altitude and temperature. No model I am aware of forces that rate to be equal to C/C by some explicit equation or constraint. (Caveat: personal detailed knowledge is CAM3). But AR4 clearly says that is the general model result. Discussed multiple places; so important got AR4WG1 special note 8.1.
It is obvious that lapse rates are not locally constant. The lapse rate inside a T storm is much lower, and in the descending exterior dry air column much higher. So a cell average is influenced both by the number and power of these convection cells.
It is now quite certain that models overstate upper troposphere specific humidity. This is knowable directly in three ways. First radiosonde observations corrected for known instrument dry biases. Many instruments, lots of corrections. Second, via microwave satellite sensors. Third, by the newest GPS enabled method. See Arts of Truth for examples. It is knowable indirectly by the modeled tropical troposphere hotspot that does not exist observationally. See Christy’s APS testimony in essay Humidity is still Wet. A direct consequence of overstated water vaper feedback.

Reply to  whiten
February 18, 2015 7:43 pm

Thanks again really appreciated.
Ok, now if I have got this right, hopefully…..I am very aware that I have being driving blindly thus far only by been guided from you.
But for what is worth that what I have got thus far:
In the case of a tropospheric rH variation is required only a slight “overloading” of either UT or the LT in regard to each other, meaning that the rH of one varies slightly more than the other (to a significant point) for a condition of a troposphere heat accumulation to arise, either sourced from a UT or LT heat accumulation, which ever be the case…………while that will be manifesting as a hotspot in modeled tropical troposphere, which actually does not exist,………. or and as an increased warming (artificial) in the projections of the GCMs.
Seems like all needed is the overstated upper troposphere’s specific humidity, which may be enough overstated by the models, for these given condition to arise (the slight rH variation “overloading” of LT in regard to UT).
Gosh hopefully that is something that makes sense, otherwise I will be scratching my head for some time longer….:-)
thanks very much…appreciated.

February 18, 2015 9:21 am

Sounds like Ramanathan is enamored by the postulated “super greenhouse effect” for the earth when in several billion yrs the oceans completely evaporate and reside in the atmosphere.
Prb’ly needs to get back to the more relevant present….

Data Soong
February 18, 2015 10:04 am

Great work as always, Willis! It would be interesting to see what the plots of dewpoint (or water vapor mixing ratio, or water vapor pressure) look like, as these measure humidity in more absolute terms (whereas RH is highly inversely correlated with temperature.)

Reply to  Data Soong
February 18, 2015 10:28 am

+1…beat me to it.

Reply to  Data Soong
February 18, 2015 10:45 am

Trane has an interactive psychrometric program/graph on their commercial site. Easy to see how moist air parameters/moisture content/energy content, etc. are related.

February 18, 2015 10:27 am

Willis, I really enjoy reading your posts. Here, you study RH and draw conclusions based on it.
“…But instead of the RH increasing with sea surface temperature (SST) to engender a “super greenhouse effect”, the reverse is true. As the ocean temperature rises, the relative humidity falls.”
I have never been comfortable with RH because it’s derived from two variables: Air temperature and Dew Point (water content). In your figure 9, the lion’s share of the RH fluctuations are driven by temperature masking the fluctuations in water content (DP) resulting from the competing influences of ocean surface evaporation and downwelling of drier air aloft. Most of the time it’s easier for me to see relationships by viewing dew point rather than RH because the fluctuations of temperature are removed.
Nevertheless, yours was a great post. Thanks for all your hard work.

Reply to  hifast
February 18, 2015 3:17 pm

RH is the ratio between the current grains of moisture per lb dry air and grains per lb of saturated air at constant dry bulb temperature. This change also requires an enthalpy increase from 22.75 Btu/lb to 30.06 Btu/lb. Dew point isn’t involved. Dry bulb and dew point only tell you what the RH is.
Air (CO2?) moves energy at 0.24 Btu/lb-F
Water moves energy at 1.0 Btu/lb-F
Evaporation/condensation of water vapor moves energy at about 1,000 Btu/lb.
Guess which one is the 500 lb gorilla?

Kevin Kilty
February 18, 2015 11:02 am

It is interesting to parse some of Ramanathan’s statement

The greenhouse effect in regions of convection operates as per classical ideas, that is, as the SST increases, the atmosphere traps the excess longwave energy emitted by the surface and reradiates it locally back to the ocean surface.

Of course this can go on only so long because it represents a constant increase in surface temperature. One of two things occurs. 1)At some point some process limits the temperature increase, or, 2) the posited feedback does not actually occur in the first place.

explanation for the water-vapor feedback among the early studies of climate sensitivity was the fact that the relative humidity of the atmosphere is invariant to climate change.

This is an odd one. More properly one should say that an “assumption” not explanation for the water vapor feedback is the idea of constant RH, but there is no physical basis for such a conservation principle, is there? Usually the justification is the clausius-clapeyron relationship, but this pertains to equilibrium, and where exactly does equilibrium hold over large regions or for long periods of time?
Of course, Ramanathan might reply that while the relationship that Willis illustrates here is true, and is also true in the enhanced greenhouse world, but all of the curves are found at slightly elevated values.

combination of increase in humidity in the entire column and increase in the lapse rate within the lower troposphere.

I have heard climate scientists and meteorologists alike state that convection raises the lapse rate and makes the atmosphere less stable, but surely the atmosphere is more or less inherently stable and convection and precipitation are responses to disequilibrium disturbances that return the system toward a more stable state. Also I have trouble understanding why the lapse rate necessarily increases. Within a convective storm the lapse rate must decrease because of the latent heat released (i.e. look at the difference between the dry adiabat and a wet adiabat). The final state of the atmosphere after pronounced convection and the release of latent heat might be to decrease the lapse rate. Anyone have thoughts on this, or data?

Joe Born
Reply to  Kevin Kilty
February 18, 2015 12:00 pm

“Of course this can go on only so long because it represents a constant increase in surface temperature. One of two things occurs. 1)At some point some process limits the temperature increase, or, 2) the posited feedback does not actually occur in the first place.”
That’s not precisely true. If x is the input and there’s positive feedback f, then the output y is given by y = (x + fy) A -> y = Ax / (1 – Af). This wouldn’t blow up if Af < 1.

Kevin Kilty
Reply to  Joe Born
February 18, 2015 12:57 pm

You are correct here. I just saw his statement as being ambiguous, as it didn’t mention feedback (i did), but rather the trapping and return of “the” increased emittance.

Reply to  Kevin Kilty
February 18, 2015 7:36 pm

Region-wide/Ocean basin-wide pressure patterns are essential components of the smaller scale convective areas, and the outcome of the generated water vapor. Will it get transported over a long distance to fall far from its source water area, or will the water precipitate out more locally?
Of course to review, large high pressure areas are subsiding stable air masses with clear skies, and warming surface temps which allow sw sunlight through to the water column. Convection is suppressed due to inherent stability feedbacks. Large low pressure areas support uplift, convective formation, heat dissipation above the tropopause. Tropical cycles tend to move around the periphery of large area high pressures. The predominate area-wide pressure patterns jostle around (hundred of km shifts), and seasonally move north and south with the Hadley cells shifts and jet stream kinks.
Examples: The Ridiculous Resilient Ridge of high pressure forms in the NE north Pacific Ocean, the surface temps and SST warms as SW heating of the water column is favored. When it abates or shifts westward, a cloudier, convective water column cooling patterns moves in its place.
Over in the North Atlantic Late summer, the clockwise Bermuda High keeps the highly unstable tropical disturbances rolling off the west African super-heated Saharan desert generally moving westward with the trade winds. Tropical storm development needs to operate within a larger stable air mass if they are to strengthen, since horizontal shearing away of convection cells that manage to punch through the tropopause are the biggest inhibitors to further growth.
Understanding humidity at the surface is just one variable in a complex system.

February 18, 2015 11:39 am

With knowledge that temperature is a measure of a kinetic distribution, then the notion of ‘heat trapping’ in the lower troposphere must, by definition, increase the mean kinetic energy beyond that calculable without its incorporation. There must be a significant discrepancy if this effect exists and modifies the lower tropospheric temperature profile.
Taking values of temperature, pressure and height of the tropospheric/tropopause boundary from
T= 192.5K
Altitude 17km
We can calculate the potential temperature (surface) for a diatomic mix of nitrogen and oxygen from the isentropic flow equation by substitution of T(trop min) at the tropopause boundary pressure.
Isentropic flow equation
T(1)/T(2)= (P(1)/P(2))^(gamma-1/gamma)
Where gamma for a diatomic is 1.4 as used for engineering purposes, ((7/2)/(5/2)).
This gives an isentropic equilibrium temperature for the surface pressure of ~381K.
This differs from measured surface temperatures by around deltaT= 76K higher, for measured T(surface)~305K (32degC)
This is an energy gap of some 76 times the specific heat capacity of dry air difference. Cp for dry air is 1,005J/kg
Therefore the energy gap is 76,380J per kilogram of dry air.
How much liquid water can we vaporise with 76,380J/kg,
Evaporation heat of water is 2501J/g
Therefore 76,380/2501= 30.5g per kg of previously dry air.
32K and specific humidity of 30.5g/kg are not unreasonable figures for tropical humidity conditions calculated from the conditions of the upper troposphere and ignoring back radiative enhancement.
There is NO EVIDENCE of enhanced surface energy due to radiative heat ‘trapping’ within the lower tropical troposphere. Nor anywhere else!

Quinn the Eskimo
February 18, 2015 11:46 am

As usual, very interesting, Mr. W.
As luck (?) would have it, I happened to be reading “Water Vapor Feedback and Global Warming,” by Isaac Held and Brian Soden, Annu. Rev. Energy Enfiron. 2000. 25:441-75, which has some bearing on the assumptions you are questioning with this analysis.
Some relevant bits:
“The first results of sensitivity of such a climate model to an increase in CO2 were presented in 1975 by Manabe & Weathereld with an atmosphere-only model over an idealized surface with no heat capacity, no seasonal cycle, and with fixed cloud cover. The equilibrium sensitivity of global mean surface temperature obtained was app. 3 K for a doubling of CO2. The model produced only small changes in relative humidity throughout the troposphere and thereby provided the first support from such a model for the use of the fixed-relative humidity assumption in estimates of the strength of the water vapor feedback.” p. 453.
“In particular, all comprehensive climate models of which we are aware produce increases in water vapor concentration that are comparable to those predicted by fixing the relative humidity.” p. 454.
Their validations, like the comment above, compare annual or monthly means in observations to model output averaged over comparable periods:
“Following Raval & Ramanthan, in Figure 2(a) we use ERBE observations to plot the annual mean clear sky greenhouse effect … over the oceans … . A simple inspection of these figures reveals several important features regarding the processes that control the atmospheric greenhouse effect.”
“The magnitude of greenhouse trapping is largest over the tropics and decreases steadily as one approaches the poles. Moreover, the distribution of the clear-sky greenhouse effect closely resembles the vertically-integrated atmospheric water vapor (Figure 2(b); see color insert)[annual means]. The thermodynamic regulation of this column-integrated water vapor is evident when comparing this distribution with that of surface temperature (Figure 2c; see color insert) [annual means]. Warmer [sea] surface temperatures are associated with higher water vapor concentrations, which in turn are associated with a larger greenhouse effect. Regressing G(clear) versus Ts over the global oceans, one finds a relationship that is strikingly similar to that obtained from radiative computations assuming clear sky, fixed lapse rate, and fixed relative humidity.” p. 449-450.
Willis is looking at hour by hour data, which reveals important phenomena that invalidate the assumptions of fixed relative humidity. These phenomena are obscured by the use of monthly or annual means. This is the final interesting bit I will quote:
“If the value of [water vapor feedback] were larger than unity, the result would be a runaway greenhouse. The outgoing infrared flux would decrease with increasing temperatures. It is, of course, self-evident that the Earth is not in a runaway configuration. But it is sobering to realize that it is only after detailed computations with a realistic model of radiative transfer that we obtain the estimate [water vapor feedback] = app. 0.4 (for fixed relative humidity). There is no simple physical argument of which we are aware from which one could have concluded before hand that [water vapor feedback] was less than unity. The value of [water vapor feedback] does increase as the climate warms if the relative humidity is fixed. On this basis, one might expect runaway conditions to develop eventually if the climate warms sufficiently. Although it is difficult to be quantitative, primarily because of uncertainties in cloud prediction, it is clear that this point is only achieved for temperatures that are far warmer than any relevant for the global warming debate.” p. 449.
So, have they fooled themselves into believing the assumption of fixed relative humidity is correct?

Reply to  Quinn the Eskimo
February 18, 2015 12:04 pm

“But it is sobering to realize that it is only after detailed computations with a realistic model of radiative transfer that we obtain the estimate [water vapor feedback] = app. 0.4 (for fixed relative humidity). There is no simple physical argument of which we are aware from which one could have concluded before hand that [water vapor feedback] was less than unity”
Actually there is a simple physical argument to that effect which I have set out previously.
In so far as water vapour is a greenhouse gas it can radiate energy directly to space from within the atmosphere.
In doing so it reduces the total amount of energy (kinetic and potential) held within the atmosphere.
The result is that less energy is returned to the surface in adiabatic descent trhan is removed from the surface in adiabatic ascent.
That reduction in energy returning to the surface is evidenced by the water vapour feedback being less than unity.
However, it does’t cool the surface because at the same time those water vapour molecules are also warming the surface to an equal extent with the net thermal effect at the surface being zero.
The thermal effect of radiative molecules in an atmosphere is always offset by an equal and opposite thermal effect from changes in the balance between adiabatic ascent and adiabatic descent.

Reply to  Quinn the Eskimo
February 18, 2015 6:54 pm

In the more complex CMIP5 archive it is about 0.5, cloud feedback is about 0,15 and the total is about 0.65-0.67. All the Bode 1/(1-f) feedback equation. Correct values seem be on order of cloud ~0, WV ~0.25-0.3. Those give an ECS on order of 1.7-1.8. Derivations in Arts of Truth and essays in Blowing Smoke and elsewhere in comments. When two parameters (of 5) are better estimated in Moncktons irreducibly simple model (see my comments on that thread), the equation produces ~1.75. Remarkable agreement.

February 18, 2015 12:49 pm

I concur Willis – today the air is cool and dry in Hervey Bay – the very distant outskirts of an approaching cat 2 cyclone.

Matthew R Marler
February 18, 2015 1:53 pm

Willis, thank you for another good essay.
The recurrent claim of unchanging relative humidity is a puzzle.

February 18, 2015 1:53 pm

Excellent analysis but there is a flaw. Pardon me if others already touched on this point.
The flaw is that you consider relative humidity rather than absolute humidity.
You wrote:
“But instead of the RH increasing with sea surface temperature (SST) to engender a “super greenhouse effect”, the reverse is true. As the ocean temperature rises, the relative humidity falls.”
If we heat a parcel of air containing water vapor, the “relative” humidity will fall even if total vapor content is unchanged. This is because relative humidity expresses the amount of vapor in the air relative to the maximum amount that could exist at that temperature. Air at 50°F and 100% relative humidity as the same total water vapor content as air at 100°F and 18% relative humidity.
It’s often said that hotter air can hold more humidity but this is not a precisely correct statement because air doesn’t “hold” vapor. It’s just that more water is able to exist in vapor from when the water molecules are hotter. As ocean temperature rises, total water vapor (absolute humidity or vapor pressure) rises slightly, due to increased evaporation, but relative humidity falls dramatically because more vapor can exist when the air is warmed.
Relative humidity is always highest at night, when it’s cool, and lowest in the afternoon, when it’s warm— unless a weather system brings drier air to the area. Other things being equally, total vapor content over a windless ocean would be lower at night (cool) and higher in the day (hot).
It would be interesting to see a rework of your analysis using absolute humidity rather than relative humidity.

Reply to  Thomas
February 18, 2015 3:20 pm

Relative uses pounds, absolute uses cubic feet. It’s the pounds that carry the energy.

Reply to  Thomas
February 18, 2015 4:46 pm

Before you ask about analyzing absolute humidity instead of relative humidity, let me ask you to verify my calc’s for generating relative humidity from 2 meter air temperature, wet bulb temperature, and local air pressure.

2012	10	1	12	-8.2	-10.1	0	4	0	1010
2013	6	1	16	3.2	-3.8	0	4	0	1016
2011	10	1	18	-18.1	-20.7	0	4	0	1006
2011	11	2	4	-20.9	-24.9	0	4	0	 980
2011	11	3	2	-22.6	-25.8	0	4	0	1013

This info is for a site much colder than the tropics (Barrow AK) but I do want to verify my conversion from the raw numbers above is right.

Reply to  RACookPE1978
February 18, 2015 7:57 pm

This might be a mess, we’ll see. First, of all I’m steeped in English units. Second, your table doesn’t seem to include wet bulb. Doesn’t matter. This is from Trane’s program which is produced by HandsDown software.

°F	°F	%	°F	Gr/lb	Btu/lb	lb/lb	 Vapor
DB	WB	RH	DP	W	hlb=7,000 gr	 Btu/lb
17.20	16.20	84.60	13.80	11.144	5.84	0.00159  1,075.4
37.80	32.70	57.90	25.20	19.282	12.03	0.00275	 1,073.8
-0.60	-1.30	78.00	-5.30	4.170	0.49	0.00060	 1,064.2
-5.60	-6.50	67.50	-12.80	2.761	-0.93	0.00039	 1,049.6
-9.20	-9.80	75.00	-14.40	2.523	-1.83	0.00036	 1,048.8
65.00	54.30	50.00	45.90	45.949	22.75	0.00656	 1,089.3

(H – Dry bulb * 0.24 Btu/lb-F)/lb water vapor
These are my results. Don’t see your RH, WB, or W for comparison.
[Set to text format for the table. (html code (pre) and (/pre) – in angled brackets for WordPress .mod]

Reply to  RACookPE1978
February 18, 2015 8:12 pm

The column labeled “Dewtemp” is their wet bulb temperature in degrees C.
Wind speed (for each of these sample lines at least) was all 0.0 knots. But wind speed doesn’t change dewpoint and 2 meter air temperature – which was also in degrees C.
Pressure is in millibars in the last column (Yeah – metric again.)

Reply to  RACookPE1978
February 18, 2015 9:48 pm

What is 2Mtemp and what are the units?

Reply to  Thomas
February 18, 2015 10:11 pm

2MTemp is the dry bulb air temperature at 2 meters above ground, degrees C.
I looked again through emails for the original text file, but have only the resultant Excel file.
The other column, what I improperly said above was “wet bulb temperature” earlier, is DewPoint temperature, also in deg C.

Reply to  RACookPE1978
February 18, 2015 10:35 pm
2012	10	1	12	-8.2	-10.1	0	4	0	1010	86.2
2013	6	1	16	3.2	-3.8	0	4	0	1016	60.1
2011	10	1	18	-18.1	-20.7	0	4	0	1006	80.0
2011	11	2	4	-20.9	-24.9	0	4	0	1015	70.2
2012	1	2	20	-26.9	-31.8	0	4	0	1018	63.1
2011	11	3	2	-22.6	-25.8	0	4	0	1013	75.1

RH equations are:
Spreadsheet-ready equations for each unknown in terms of the two knowns:
RH: =100*(EXP((17.625*TD)/(243.04+TD))/EXP((17.625*T)/(243.04+T)))
TD: =243.04*(LN(RH/100)+((17.625*T)/(243.04+T)))/(17.625-LN(RH/100)-((17.625*T)/(243.04+T)))
T: =243.04*(((17.625*TD)/(243.04+TD))-LN(RH/100))/(17.625+LN(RH/100)-((17.625*TD)/(243.04+TD)))
(• replace “T”, “TD”, and “RH” with your actual cell references)
(• T and TD inputs/outputs to the equations are in Celcius)
Ref: http://andrew.rsmas.miami.edu/bmcnoldy/Humidity.html

February 18, 2015 3:15 pm

“but I tend to trust my own experience over theory …”
Well, there’s your problem …

February 18, 2015 3:17 pm

And I see your fish is back on your diagrams. Nice to see it again, even if it is not essential for realising the Tao of Humidity.

February 18, 2015 5:10 pm

Matches my observations in the subtropics and tropics. Gets humid and hot, then the vertical flow reaches the precipitation point and the rains come, wringing water out of the air as precipitation. The dry and cooled air then descends and everyone enjoys the cooler less humid result. Seen in even more spectacular form when a hurricane happens. Leaves much cooler water behind it and with millions of liters of water precipitated back to the surface.
Once water is hot enough to get the evaporate, rise, precipitate cycle going, added heat does not result in more temperature increase, but shows up as more mass flow of water vapor; thus the flatter temperature curves. As a heat pipe engineer and I’m sure they can give the engineering details of it.
Nicely done W.

Reply to  E.M.Smith
February 20, 2015 4:39 am

It’s as simple as this: Without convection you will get a hot and humid (‘sticky’) layer of air close to the surface. The heat transferred from the surface to the lowermost layer of the atmosphere (by conduction, radiation and evaporation) simply cannot effectively escape to higher regions, and so it piles up (after all, the heat is still coming in from the Sun). Convection on, however, and both the accumulated energy and the accumulated water is swiftly brought up and away. Cooling and drying.

February 18, 2015 6:44 pm

Excellent post, thank you Willis. I enjoy the clear logic and curiosity of your work.
While what you have done here raises hundreds of good questions – most of which I am ill equipped to help with – the question that really interests me is why are these people so bad at science?
I think there are 2 reasons:
1. They are not prepared in the sciences to do science and so examination of their work always seems to deconstruct their work.
2. They lack scientific curiosity, which you demonstrate here.
When they happen upon a graph or a number that meets their need, they think they’re done. Not interested in looking further. They are not curious which is fundamental characteristic of a real scientist who now has bunches of new questions to consider.

Peter C
February 18, 2015 8:21 pm

Thanks Willis,
You seem to have answered a question I had.
I have been looking at the meteorological data at an Australian Bureau of Meteorolgy site called Giles in central Australia. The dew point is highest in the early morning and deceases during the day as the temperature rises. Dew point is a measure of the water content of the air.
So I wondered; where does all the moisture go? Well the answer seem to be that it goes up (with the thermals, which go over 10.000ft) and is replaced by drier air coming down from above.

Reply to  Peter C
February 18, 2015 10:16 pm

I think you’re close to showing compelling evidence of your posited equatorial cloud-based thermostat but you’re missing some fundamental physics.
“If these TAO data findings are correct, and if relative humidity more generally is not constant with respect to temperature, it would seem that this would greatly reduce the amount of purported water vapor feedback …”
Specifically, “if relative humidity … is not constant with respect to temperature.”
If water vapor is constant, “relative” humidity will NOT be constant with respect to temperature because it is a relative value—relative to the amount of vapor that could exist at the now elevated temperature. If vapor content is constant and temperature is increased, relative humidity will decrease.
Also, the intertropical convergence winds carries moist air from the subtropical seas to the band of equatorial convection clouds. It’s not gaps in the equatorial clouds that represent the down-welling air. It’s air over the oceans north and south of the equator that converge at the equator to supply the moisture for the equatorial clouds. These areas are oceanic deserts where very little rain falls but much moisture evaporates.

February 18, 2015 10:36 pm

Correction: It is unquestionably true that equatorial convective storms have a damping effect on the earth’s temperature. They reflect sunlight and shade the surface below so that the surface is cooler than it would otherwise be. Still, your analysis errs in using relative humidity because relative humidity is not a measure of total water vapor content and it is total vapor content that controls the local greenhouse effect.

Reply to  Thomas
February 19, 2015 5:23 am

RH is a measure of total water vapor. It’s the ratio between pounds of actual water vapor and pounds of water vapor at saturation.

Reply to  Willis Eschenbach
February 20, 2015 5:51 pm

Willis, you are right about the relative humidity thing. Your analysis actually fails because you were looking at surface level humidity and Ramanthan was looking at total column humidity.
You quoted from the abstract of Ramanthan’s paper “Physics of Greenhouse Effect and Convection in Warm Oceans” (1994) wherein he wrote that, “tropospheric relative humidity is larger in convective regions.” Ramanthan also wrote that the increased greenhouse effect was caused by an, “increase in humidity in the entire column.”
These statement are clearly correct. Convection causes an increase in total column relative humidity because water vapor is lifted far above the sea surface. Without that lifting there would be no cloud formation so it’s obvious that it is actually happening.
Your charts of TAO data show changes in relative humidity near the surface. This does not address Ramanthan’s statements about total column, tropospheric humidity (whether relative or absolute) because you’re looking only the humidity only near the sea surface.
However, it’s interesting to note that Ramanthan also says that his “radiation model calculations do not include the effects of clouds.” He used a model to study the greenhouse effect of increased water vapor but ignored the fact that the water vapor will cause cloud formation, which will cause surface cooling because clouds reflect sunlight.
Ramanthan’s whole exercises is rather obvious—(a)water vapor is a strong greenhouse gas, (b) convection of moist tropical air increases total column vapor, so (c) the greenhouse effect is larger. I don’t think we benefit much from a detailed model-study of this effect. Any first-year metrological student would know the answer.
Furthermore, calling it a “super greenhouse effect” is a gross exaggeration. There is nothing “super” about the effect, unless you ignore clouds.
Ramanthan’s model experiments certainly do not provide evidence to support the hypothesis that CO2-induced warming will produce a significant positive feedback. As you have so elegantly explained, the warmer the ocean gets, the more clouds form, so the ocean gets cooler. Ramanthan ignored the clouds so his paper can’t be a refutation of your theory.
As for the effect of tropical storms on surface relative absolute humidity, it’s somewhat counter intuitive but the near-surface humidity is often lower when it rains. When rain falls it drags air with it and this air has a low water vapor content because most of the water is now in the rain droplets. These downdrafts warm due to compression and through mixing with warmer near-surface air. This means water vapor content near the surface when rain is falling is often lower.
I looked at weatherunderground.com and found a random day in Miami that had a thunderstorm (August 20, 2014).
Here’s what I found:
Just before rain began (13:30)
32.8°C with 57% RH = 0.018 kg of water vapor per kg of air.
When rain was falling (14:00)
21.1°C with 77% RH = 0.016 kg of water vapor per kg of air.
The absolute humidity at the surface decreased by 20% when rain was falling.

February 19, 2015 5:29 am

“The column labeled “Dewtemp” is their wet bulb temperature in degrees C.”
Dew point and wet bulb are NOT interchangeable. Dew point says how much vapor is in the air, wet bulb says how much more vapor the air can absorb. Wet bulb is a measure of the moist air’s heat content. With dew point heat content decreases as it condenses out reducing the sensible heat, i.e. dry bulb.

Don V
February 19, 2015 6:48 am

Willis, I always enjoy reading your musings and follow-up analysis. Especially since you follow the data wherever it leads. I have commented before on the water-cycle “thermostat” concept that you are exploring further in depth in this blog, and might as well throw the same thoughts into the comments on this one as well. Some of my past observations to add to yours:
1) IR photos from space looking down on the oceans during very large storms (hurricanes) at night always show areas of light and dark “radiation”. IMHO this has to point to where IR radiation is given off from the storm. You do in fact see striations in these images, areas where active “radiation” is occurring and areas where no (or less) radiation is occurring (see for example: http://www.space.com/18236-frankenstorm-hurricane-sandy-satellite-photos.html)
2) Also IMHO, the evaporation of water (liquid to gas), sublimation (solid to gas) as well as the transport of water vapor upwards all have to be processes that are energy losing processes (that is it takes energy from the system to make each of these processes occur). The energy that is “lost” (ie that is transferred to the water molecules) from the “system” is radiative. During the day (while radiation is actually coming into the system) some of the radiative energy is absorbed by water vapor and some is also reflected back to space. The radiation that enters the top of the atmosphere and actually makes it to the ocean is absorbed, and “lost” to excited (liberated) water vapor molecules. Therefore, when condensation (or melting) occurs in a cloud the converse must also be true as well – radiative energy must be released. During the night, no net radiation is coming into the top of the atmosphere. Therefore, these IR pictures of a huge storm at night must show us WHERE radiative energy loss to outer space from the cloud is actually occuring. The picture tells the story of where the cloud is “glowing” and giving off extra energy in the infrared. (You’ll also notice in these pictures that although there is a similar amount of CO2 over the uncloudy water regions, you don’t see anywhere near as much IR radiation as you do coming from a cloud – in fact you see black, none, nada, zip.)
3) Also IMHO, when you look at a nice thunderstorm forming on the horizon, what you see visually shows evidence of where you should also see the most IR radiation. You nearly always see a distinct band where the bottoms of the clouds begin. You also see a distinct band where the top of thunder heads form the “anvil”. Both planes of demarcation give evidence that this is the elevation where the water cycle is dramatically changing phase (crashing?). IMHO it should be at those phase change locations where the most release of stored energy back to IR occurs.
4) In his excellent presentation “Water, Energy, and Life: Fresh Views From the Water’s Edge”
( https://www.youtube.com/watch?v=XVBEwn6iWOo ), Dr. Gerald Pollack introduced us to the concept of water droplets in a cloud actually self forming a liquid crystal phase all around the outer surface of each tiny condensing water droplet. In his presentation, he provided evidence that the energy engine that created this phenomenon was infrared energy. He also noted the appearance of a charge separation within each condensing droplet that does at least two amazing things. First, it enables clouds to self organize and not “disperse” or diffuse away. Second it stores even more energy (ie sucks IR radiative energy out of the surrounding milieu and into condensed cloud droplets). So this suggests that “inside” clouds water droplets that are forming liquid crystal films around there outer surface, must be IR sinks. The most dramatic event in a cloud that releases this accumulated energy is a lightning strike (radiative across the visible spectrum – extremely energetic radiative release).
5) Finally, its a shame that the buoys you got the data from for this analysis don’t also provide:
a) a straight-up-looking visible and IR spectrum of the intensity of light hitting the buoy to get an instantaneous picture of what radiative transfer is occurring back down from under clouds vs back down from when rain is occurring,
b) a simultaneously measure of CO2, methane etc. to give us a picture of what the other (inconsequential) green house gas concentrations are doing. I suspect that every day after a good rainstorm the CO2 dramatically drops (is scrubbed from) the atmosphere. I also suspect that the change is much greater that the slow average annual drift that has warmists all in a tizzy.
So, have you ever had any thoughts about adding “liquid crystal” thermodynamics to your overall thermostat concept? I suspect it is NOT a minor effect but rather may be nearly as large as latent heat transfer, and specific heat/convective transport. Secondly, in your analysis of the data, can you distinguish a difference between when a buoy goes through a day where it is in the path of a storm – experiences the before and after effects of a good rainstorm – versus when it goes through a day and no rain falls on it? What do those data “pictures” show regarding thermostasis?
Respectfully, DonV

February 19, 2015 7:22 am

“The energy that is “lost” (ie that is transferred to the water molecules) from the “system” is radiative.”
I disagree. As water evaporates it influences the air/liquid sensible temperatures through conduction not radiation. Consider what is happening in one of those enormous utility wet cooling towers.

February 19, 2015 11:37 am

Wow, did I halt another thread?

February 20, 2015 1:01 am

I do not understand the x-axis on your figure 4. Perhaps that should be in whole integers, not tenths.

Reply to  mpainter
February 20, 2015 3:49 am

Willis, never mind. I see the diurnal temperature variation is less than 1° C, most remarkable.

February 20, 2015 4:24 am

Thanks for this exposition. Very illuminating, very useful.

February 20, 2015 8:25 am

As noted by Willis and several commentators above, folks who have spent time in tropical and semi-tropical climates know very well the sudden cool dry winds that may come before or after a thunderstorm, and the chilling effect of a deluge of cold water and/or ice on a sweltering afternoon. Sometimes the heat may return in a few minutes, but often the heat of the day is broken by such a passing storm and the remaining towering cloud forms which block the sun as it sinks in the afternoon sky. In some locations this is almost a daily occurrence. As Willis noted, the resulting daily temperature cycle is hardly smooth, with temperatures and relative humidity dropping associated with a thunderstorm, then temperatures rising to new lower highs and relative humidity rising as the standing water is evaporated while cooling the ground and man-made pavements and structures.
I am curious how BEST and other agencies homogenize temperature readings taken during or after such sudden cooling events, and if anyone has a handle on how the actual energy sums and balances change during the process. One would think that until model grids are fine enough to see these events and until the models measure net energy balance instead of temperature, then they will be doomed the trash bin.

Dr. Strangelove
February 21, 2015 4:06 am

“A simple explanation for the water-vapor feedback among the early studies of climate sensitivity was the fact that the relative humidity of the atmosphere is invariant to climate change… Although it is well known that atmospheric circulation plays a big role, a satisfactory answer as to why the relative humidity in the atmosphere is conserved is still elusive.”
As ocean surface evaporates, it has cooling effect on surrounding water not evaporated because evaporation is an endothermic process. When water cools below the vaporization temperature, evaporation stops. The relative humidity may be the same but absolute humidity increased because of warmer air temperature. Also, as warm air rises, it is replaced by cooler air that cools the water surface and convective cooling repeats the cycle.

Don V
February 21, 2015 9:46 pm

nickreality65 You wrote:
“I disagree. As water evaporates it influences the air/liquid sensible temperatures through conduction not radiation. Consider what is happening in one of those enormous utility wet cooling towers.”
I’m sorry, I respectfully disagree with this statement. I am a biochemical engineer, and I have had to solve for huge heat transfers in production plants and had to size heat exchangers. I too was taught that conduction and convection were the most efficient modes of getting rid of excess heat. When sizing cooling towers, we were never taught what happened to the heat that left the cooling tower as water vapor but then almost immediately condensed into a cloud just outside of it. Just consider for a moment what the picture looks like if you back out farther and look at the bigger picture – from outer space for instance. Since there is no conduction of heat to space, (nor any convection for that matter) when you pay attention to all the the little transfers of heat from the surface of the ocean all the way up to space, each little energy diagram for each “layer” of the atmospheric ocean” has a net radiative heat “in”, a net radiative heat “out” and what seems to be a net radiative heat “loss”, (or “gain”?) which is the difference between the two. Conduction and convection get all mixed into the process and serve to effect good mixing between the phase change layers, but my argument is that it is not safe to assume that the ONLY heat that is transferred, is by conduction or convection alone. Whenever a phase transition occurs some of the energy gained or lost in the process MUST BE RADIATIVE as well. It is myopic to ignore this possibility. Why do I think that? For two simple reasons.
First, at phase change, no temperature change occurs in the compound that is changing phase, while it is occurring, but the Entropy changes. To effect conduction or convection, all the equations that I had to memorize had a DELTA T term in them. The radiation equation just has a T term – no delta.
And the second, is what I mentioned in my argument above. IR photographic evidence from outer space. Why, in a black and white IR photo from outer space looking down on a storm in the middle of night, when you have NO IR or any light for the matter coming in from the sun, do you see different amounts of IR emitted back out to the camera – between a “black” (ie no IR) ocean surface (that is basically sucking up all the IR that hits it), and the top of a storm cloud (different shades of grey and white caused by the IR that is being given off)? In the picture of Sandy that I referenced, the storm was producing all kinds of IR, and yet the ocean was not, even though the ocean surface at the equator was warmer than the ice crystals at the top of the storm pelting the New England coastline. Or as a second example, why in the multi-colored pictures of the IR spectrum over the whole planet do we see lots of RED over tropical areas where lots of clouds and T showers are occurring, and lots of cool green where they aren’t?
(see for instance a spring day in 1985 http://en.wikipedia.org/wiki/Heat_transfer#mediaviewer/File:Erbe.gif )
I suspect it is because water phase change events in storm clouds are producing a heck of a lot of IR radiation. If we could actually see this with our eyes, I suspect that the storm would appear to “glow” with different intensities depending on what “layer” or area we are looking at, with the “brightest” glow emanating from where ever the most energy is being given off by the condensation or freezing of water. I suspect also that if we had IR sensitive eyes and we looked at what was emanating from one of those giant cooling towers, right where the most of the water vapor was condensing back to water droplets we would see a bright IR glow (especially if we could simultaneously reference that image to the much cooler evaporative process inside the tower and the water from which all that energy was extracted at the bottom of the tower).
What is going on here in my thought process is to question what I was taught where there was no factual evidence to back it up. So although I too was taught to ignore everything that happens to the water after it left the cooling tower (ie. where the energy ends up actually going) and your statement “As water evaporates it influences the air/liquid sensible temperatures through conduction not radiation,” is most likely true for sizing purposes inside the tower. I believe my arguments above, concerning phase change events actually causing an increase in radiative transfer off the planet, are well supported with the evidence.

February 24, 2015 12:31 pm

That this paper is not pulled simply for the use of the childish term “super greenhouse” is a tell that it is yet another bit of climate tripe. That the author gets the physics as wrong as he does is not actually surprising. Thepurpose of climate hype is not to accurately discuss the science. It is to keep the faithful in line.

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