Guest Post by Willis Eschenbach
Despite doing lots of research and investigations over the last few weeks, I’ve written little. Well, actually, I’ve published little, although I’ve written a lot. But I didn’t publish what I’d done, there was no wonder in it, no awe. So I tossed it all out and started “simply messing about”, as the Toad had it. For no apparent reason, I got to looking at the various methods for estimating the downwelling longwave radiation (DLR) based on surface conditions. DLR is the radiation emitted by the atmosphere which is directed downwards towards the earth. There’s a good summary of the various DLR estimation methods here.
In any case, I wanted to compare the estimated DLR to the DLR from the CERES satellite observations. I used the “Brunt” method, which calculates an “effective emissivity” from the vapor pressure. The vapor pressure in turn is calculated from the surface temperature. I subtracted the satellite observations from the Brunt estimate. Figure 1 shows the result.
Figure 1. Difference between the downwelling longwave radiation (DLR) as calculated by Brunt, and the downwelling longwave radiation dataset from the CERES satellite data.
I busted out laughing when I saw that graphic come up on the silver screen. I do my science visually, by painting the transformations and relationships in color. And in general, I have only the vaguest idea of what any given graphic will look like before it is displayed. So watching the graphics appear onscreen is like opening a line of scientific presents. Each one is unexpected, each one reveals new things.
This one was funny to me because it was such an excellent and detailed map of the desert and arid areas of the planet. From the Sahara to the Atacama Desert, the Gobi, the American Southwest, the Arabian Peninsula, the Namib Desert, it’s all laid out in precise detail. Heck, you can even see the green areas of Australia as a thin strip along the east and north coasts.
This is a curious result because the CERES satellite doesn’t measure water vapor … but what we have in Figure 1 is a map of water vapor. Over the desert areas we get less downwelling radiation than the estimate suggests, because water vapor is the main greenhouse gas. In the desert the air is so dry that more radiation escapes to space, and less is absorbed and radiated downwards (and upwards) by the atmosphere. It also shows the moistest areas of the planet (dark green and blue). These are in the equatorial tropical forests, where transpiration combines with evaporation. This leads to lots of water vapor, and a concomitant increase in DLR above what the estimate suggests.
This is the first time I’ve looked at the difference between a variable in the CERES dataset and an estimate of that variable. They say that all models are wrong, but some are useful. This model of downwelling longwave radiation is obviously wrong … but it’s useful because of exactly where and how much it is wrong.
Which leads to the final surprise for me, which was the size of the deviations from the expected DLR. From very dry regions to very wet regions is a range on the order of 100 W/m2 of downwelling LW radiation … I didn’t think it would be that big.
Anyhow, that’s the kind of thing I like to write about—the unexpected. For me, the adventure of science is never knowing which bush might be the one that hides the rabbit …
Regards to everyone,
w.
As Always: If you disagree with someone, please quote their exact words so we can all understand your objection.
A note on the Brunt Method: The Brunt method estimates the “effective emission” as a function of the form
a1 + a2 * sqrt( vapor_pressure )
Per the above citation, the canonical values for a1 and a2 are 0.51 and 0.066.
When I fitted the values, I got a1 and a2 as 0.65 and 0.029. I thought this might be a result of including the ocean. So I looked at just land, which gave a1 and a2 as 0.65 and 0.024. And looking at just the ocean I got 0.66 and 0.030. None of these are near the values given in the reference. However, they work quite well, and the canonical figures give much larger errors. Go figure.
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My little experiment. What am i doing wrong, I can sit near the fire sideways ( representing the sun) i get a large copper spoon and reflect the fires heat onto my face.
My face being the earth? lower atmosphere, One side of my face is hot from the fire, the other facing away is cold. I can direct the fires heat onto my cold side with the copper spoon – amazing the heat it gives, feels about the same as the side facing the fire. So now i move the copper spoon to face the fire and the side of face facing the fire. So double warming and back radiation – this side feels no warmer with or without the spoon. I thought back radiation or double reflection from the fire would make it seem warmer- that seems to be the premise behind gorebull warming.
You feel the flux of the differences in temps between the fire and your face, the difference the spoon adds is minimal, so it feels and is approximately the same.
BTW a gold spoon would work better.
Another problem with your spoon (if I understand the geometry of the setup…and I am not sure I completely do) is that it absorbs or reflects the radiation from the fire effectively. Greenhouse gases absorb the Earth’s infrared radiation effectively but do not absorb very much in the near infrared, visible, and ultraviolet, which are the wavelengths that the sun radiates. So, they act sort of like a 1-way mirror (not a precise analogy, because they absorb and subsequently emit, rather than reflecting…but close enough).
It is said that a hotter body emits more energetically at all frequencies than a cooler body so there should be more solar IR at 15 microns than terrestrial. Is there?
The Sun is much warmer, the longest solar is 1-2u, much shorter than the shortest terrestrial IR.
micro6500,
I was aware that the sun is much warmer than the Earth.
My question to you would be; how many watts per square meter are measured at TOA at 2 microns (solar) and why are there suddenly zero at 3 microns?
Are you encouraging me to disbelieve that hotter bodies emit more energetically at all frequencies?
The Sun emits more IR per unit area of its surface. But it is a long way away, and occupies less than 1/10000 of the sky. The thermal IR that we get from the rest of the sky far exceeds solar (thermal) IR.
Nick,
I don’t see how that possible, for instance I stuck the IR thermometer out the door tonight, and the sky measured -70F, where the ground is a balmy 20F or so.
joeldshore said:
“Greenhouse gases absorb the Earth’s infrared radiation effectively but do not absorb very much in the near infrared, visible, and ultraviolet, which are the wavelengths that the sun radiates.”
False. Water vapour has several strong absorption bands in the solar near infrared. And solar NIR provides some 49% of surface heating.
In support of Nick’s point, think about it this way: The Sun emits a certain amount of Power P (energy/second) in Watts. At its surface, that power is spread out over a spherical surface that has the radius of the sun R_sun, so the intensity (in W/m^2) is P/(4*pi*R_sun^2). However, by the time that power reaches the earth, it has spread out over a spherical surface that has a radius equal to the distance from the Earth to the sun, d_EarthSun, so the intensity is reduced to P/(4*pi*d_EarthSun^2). If you put in number for the sun’s radius and the Earth-sun distance, you find the intensity is reduced by a factor of ~46000 from what it was at the surface of the sun.
Ulric,
By saying that they don’t absorb very much, what I meant was that a detailed calculation shows that the amount of Earth’s emitted radiation that is absorbed by the atmosphere is considerably larger than the amount of the Sun’s radiation that is absorbed by the atmosphere.
Sorry if that was unclear to you.
micro6500 says:
Let’s show you how it works out, at least roughly. The intensity of radiation from an object is proportional to its absolute temperature to the 4th power, which is 5800 K in the case of the sun and, say, 255 K in the case of the Earth’s atmosphere. (Your -70F is at a particularly cold location/ time of year…255 K is probably still not exactly right since it is the effective radiating temperature of the atmosphere as seen from space, not as seen from Earth, but it’s in the ballpark.)
Then we have to factor in the solid angle that the sky subtends vs. the solid angle that the sun subtends. For the sky, it is simply 2*pi steradians of solid angle (see http://en.wikipedia.org/wiki/Solid_angle ). For the sun, it is the pi*(angle that the radius subtends)^2 where the angle is ~0.25 deg and that works out to be 0.000068 steradians. The total intensity received at the earth’s surface from each object is proportional to the product of the intensity where it was emitted times the solid angle subtended (modulo discussion below).
Not worrying about constants of proportionality that are the same for both, I get [(5840)^4]*(2*pi) = 6.76×10^10 and [(255)^4]*(2*pi) = 2.66×10^10, so you can see how they end up at the same order of magnitude. In this simplistic calculation, the intensity received from the sun is still greater than from the atmosphere; however, the solar result has to be reduced by a factor of 2 to account for the fact that the sun is only in the sky for half the time and by a factor of ~0.54 to account for absorption and scattering of solar energy by the atmosphere (see, e.g., http://www.aps.org/units/fps/newsletters/200904/trenberth.cfm ). Those two factors make the intensity due to the sky larger than that due to the sun.
[Really, the calculation of intensity at the surface involves an additional factor of cos(theta) where theta is the angle in the sky from the vertical…But we are just trying to get a roughly-correct result here, not a precise calculation.]
joeldshore commented
Thanks for the details.
Okay, but at the same time the Sun is down, the rest of the sky is still -70F, what you find is that it’s the dirt that is slow to cool at night, air temps at the surface cool quickly until rel humidity gets into the 80-90%, then air temps cool slower. But in the morning, you find the dirt is 5-10F warmer than the warmest thing around, the air. And your grass is 10-20F colder than the air!
Dirt 5-10F warmer than the air, grass 10-20F colder than the air at the surface, and the sky is antarctic in the winter cold.
Then, you have the ratio of Sunshine during the day to how long it’s dark and radiating madly to space at night.
mebbe
March 28, 2015 at 7:46 pm
Might just be scale
http://tornado.sfsu.edu/geosciences/classes/m407_707/Monteverdi/RadiationStuff/energy_wavelength.gif
This has an energy scale.
An IR thermometer shows this to be wrong, While I can point it straight up and measure a temp as much as 90F colder than the ground (70F colder is pretty typical), and then point it in the direction of the Sun, don’t even have to point it and it reads over scale at over 600F.
So, we have measured IR of well over 600F from the Sun, and on the same day can measure -70F from overhead, and -30 to -40 @ur momisugly~10-15 degree’s about the horizon.
-40F is ~160 W/m2, but you do have to add the flux from Co2. Anthro Co2 is about 3.2 W/m2, total Co2 is a lot more than this, but I don’t see it equaling the Sun, nor do I think it’s 300W/m2. Now clouds are within 10 or 20F of the surface.
The point is the Anthro Co2 is a fraction of the GHG forcing, and for it to do anything it have to overcome the energy involved in multiple state changes of thousands of times the mass of water.
You can see this here.
As it warms in the spring rel humidity goes up, until temps peak then you see the relationship between increasing temps and increasing rel humidity changing, when you see this in electronics it indicates you’ve transitioned into an non-linear mode of operation. In this case it creates an energy barrier to more moisture, and maybe higher temps.
Once temps start to go down, when you include dew point, you see they daily temp record hitting the dew point every night. Another non-linearity in temp water response, another energy barrier. It is also yet another restriction of water vapor.
@joeldshore
March 30, 2015 at 9:02 am
Nonsense, you said:
“Greenhouse gases absorb the Earth’s infrared radiation effectively but do not absorb very much in the near infrared, visible, and ultraviolet, which are the wavelengths that the sun radiates.”
Water vapour has considerable absorption bands in the solar near infrared.
I would like to see a graph that shows amount of IR energy downwelling (and upwelling) versus altitud either theoretical or measured. Then try to compare that to Global Climate models.
Its the water vapour, stupid……..
Seriously, this does seem to call in question the role of CO2, even for CO2 believers. If the CO2 signal can be lost in a fog of water vapour feedbacks, then what role does it really play? You may as well say that the worst climate forcers are not the power station smoke stacks, belching CO2, but the power station cooling towers, belching water vapour.
Ralph
Close, it’s the water boiled out of the tropical oceans carried pole ward.
ralfellis March 28, 2015 at 11:20 am
Its the water vapour, stupid……..
“….., but the power station cooling towers, belching water vapour.”
Now there’s a thought. And I criticised an AGW article recently for showing a picture of a cooling tower belching H2O! Maybe they were right all along.
The amount of water vapour from cooling towers is trivial, but there is good evidence that large-scale irrigation (=increased evaporation) has significant local climatic effects, particularly on night temperatures.
ralfellis: The point is that humans cannot directly affect the amount of water vapor in the atmosphere very much, at least on global scales. This is because there is a lot more water vapor in the atmosphere (than CO2), because there are lots of huge sources of water vapor, and because water vapor cycles through the atmosphere quickly (i.e., it rains out).
CO2, on the other hand, we can and have been dramatically increasing the concentration of in the the atmosphere. And, of course, as CO2 increases and the world warms, more water vapor enters the atmosphere through evaporation.
So, in other words, we affect the concentration of water vapor indirectly by increasing the concentration of the long-lived greenhouse gases. This is why water vapor is considered to be a feedback, not a forcing.
And yet there is no actual observational evidence of the water vapor content of the atmosphere increasing and indeed no evidence that increased CO2 has in fact caused the air to warm.
Right, surface stations show no real change in rel humidity (~69-70%), and no loss of nightly cooling.
And in fact I think I know why, and night when it cools off, high rel humidity limits the maximum amount of water vapor. So I don’t think it is possible to get anymore positive feedback from water than there already is.
Actually, there is plenty of evidence for both. In particular, in regards to water vapor increasing, see the article here and references therein:
http://www.sciencemag.org/content/323/5917/1020.summary
This is another good one, a little bit older:
http://www.sciencemag.org/content/310/5749/841.abstract
Actually it’s absolute humidity that matters, not relative. However absolute humidity hasn’t increased either. Actually there is no strong theoretical reason to believe that absolute humidity would increase with temperature. The result could just as well be a slight increase in cloudiness and/or a slightly shortened atmospheric residence time instead.
At the surface rel humidity controls the maximum limit of water vapor and possibly the transparency of the atm in IR.
joeldshore March 28, 2015 at 1:46 pm
I said observational evidence, not inferred from GIGO, worse than worthless, worse than waste of taxpayer dollars models and reanalyses.
What observational evidence exists shows just the opposite of the totally unwarranted model assumptions, ie steady or falling humidity levels since the 1970s.
file:///C:/Users/John/Downloads/Inogwabini%20et%20al%202006%20Change%20in%20rainfall%20in%20Mabali.pdf
Genuine climatology was replaced by “climate science”, ie computer modeling instead of observation.
Sorry. That didn’t work.
Search for:
© THE INTERNATIONAL JOURNAL OF METEOROLOGY
October 2006, Vol.31, No.312
A DRAMATIC DECLINE IN RAINFALL REGIME IN THE
CONGO BASIN: EVIDENCE FROM A THIRTY FOUR-YEAR
DATA SET FROM THE MABALI SCIENTIFIC RESEARCH
CENTRE, DEMOCRATIC REPUBLIC OF CONGO
Sturgis,
My bad…I thought when you said “there is no actual observational evidence”, you meant there is no actual observational evidence when in fact what you seem to have meant is “there is no actual observational evidence except for all of the observational evidence that does exist and which I therefore dismiss because it disagrees with my pre-determined conclusion.”
What I linked to were evidence provided primarily by satellite observations, you know, the same sorts of observations that Spencer & Christy use to construct the UAH data set. Do you dismiss that too?
Oh, and the link you provide to prove your point is even more bizarre. It is the fact that there is an area on Earth where rainfall is decreasing. In fact, the last paragraph of that paper reads in part:
So, it looks like the authors of that study would not in any way agree with your bizarre interpretation of it.
Joel:
Satellites do not show more moisture in the atmosphere during the alleged warming during the satellite era. Only manipulation makes the supposed increased moisture appear. Even Chung, et al, 2014, before going on to engage in hijinks with the observed data, have to admit, to their credit, that, “Changes in upper-tropospheric water vapor have been examined based on satellite-observed radiances of 6.7-μm water-vapor channels (notes), which are closely related to the layer–mean relative humidity in the upper troposphere (note). Decadal trends in upper-tropospheric relative humidity exhibits distinct regional patterns associated with changes in the atmospheric circulation, but the decadal trends over larger domains are small due to opposing changes at regional scales (note). Analyzing the globalscale changes in 6.7-μm water-vapor radiances reveals little change over the past three decades.”
http://www.pnas.org/content/111/32/11636.full.pdf
I didn’t have to “interpret” the African data, since it plainly showed stable humidity. It’s your interpretation that is strange. But then, as a practitioner of post-modern “climate science”, ie computer modeling based on assumptions not in evidence rather than observing nature, no wonder.
It certainly is not easy finding papers on absolute humidity. The following is rather ambiguous in its conclusion and cautions those who are investigating this part of AGW theory. I would advise you Joel to do the same.
http://scholar.google.com/scholar_url?url=http%3A%2F%2Fciteseerx.ist.psu.edu%2Fviewdoc%2Fdownload%3Fdoi%3D10.1.1.370.5414%26rep%3Drep1%26type%3Dpdf&hl=en&sa=T&oi=gga&ct=gga&cd=8&ei=vG4XVbTACMKRqQH-tYDICg&scisig=AAGBfm370GZaVs0TnVRfcIhEyXBIvTzMeg&nossl=1&ws=1600×747
Sturgis,
Your latest reply shows you have a basic misunderstanding of your prediction. You quote a paper that says that there has been little or no global change in RELATIVE HUMIDITY (which was also what the African paper said) thinking that it supports your point when in fact it completely undermines it. The prediction of climate models is in fact exactly this, i.e., that as the Earth warms, absolute humidity will increase in such a way that, on the global scale, relative humidity will remain roughly constant. (In fact, I think if they show any trend, they show a very slight downward trend in relative humidity.) Relative humidity is the ratio of the absolute humidity to the humidity at saturation and the latter is a steeply increasing function of the temperature.
Thanks for providing us with additional evidence that this prediction is correct and your original claim that “no actual observational evidence of the water vapor content of the atmosphere increasing” is wrong!
” relative humidity will remain roughly constant. (In fact, I think if they show any trend, they show a very slight downward trend in relative humidity.) ”
What I recall from my data (NCDC GSOD) that rel humidity has a slight downward trend, but theory says there’s to be an increase as positive feedback, which based on the trend it looks like a dud.
At best rel humidity is acting like normal.
Or are you saying that normal rel humidity is a sign of AGW?
Pamela,
Paltridge et al. took a data set…a reanalysis by the way, which Sturgis tells us is GIGO…that the creators of the set warned was not reliable for long term trends and used it to look at long term trends. As has been shown by Dessler et al., this one reanalysis gets results that are different from all the others and from the satellite data: geotest.tamu.edu/userfiles/216/Dessler10.pdf It also gets results that are in complete contradiction to what are seen for the relationship between temperature and humidity for fluctuations on shorter time scales, where you don’t have to worry about changes in instrumentation and the like introducing artifacts.
Sturgis: It is worth summarizing what you have done here as an illustration and cautionary tale of how science gets abused by those like yourself who have a strong agenda that happens to run counter to the overwhelming scientific evidence. You referenced this paper: http://www.pnas.org/content/111/32/11636.full.pdf even though you didn’t like most of what it said, so you dismissed the part you didn’t like (which was almost all of it) as “hijinks” and cherry-picked one quotation that you THOUGHT supported your point, when in fact, it completely undermines your point.
This is a sad testimony of the kind of nonsense that the scientific community has to deal with from people when those people are ideologically opposed to the scientific conclusions.
Sturgis Hooper says:
And yet there is no actual observational evidence of the water vapor content of the atmosphere increasing and indeed no evidence that increased CO2 has in fact caused the air to warm.
Correctomundo. And since joelshore disputes it with his usual politics argument [“agenda”], we can be sure of who is right, based on empirical observations.
Hooper is correct, specific humidity has been declining:
http://clivebest.com/blog/wp-content/uploads/2013/03/SH400mb.jpg
Relative humidity has also been declinging, which is why the predicted tropospheric “hot spot” never appeared:
http://clivebest.com/blog/wp-content/uploads/2013/03/GlobalRelativeHumidity300_700mb.jpg
If there was long term global warming, humidity would be increasing. But it’s not. Therefore, the predictions of man-made global warming are a steaming pile of carp. QED, as they say.
Thanks, dbstealey, for further lowering the discourse by pasting graphs from the right-wing propaganda website Friendsofscience.org with absolutely no reference to where the data comes from. I believe it is from the same reanalysis that Paltridge et al. used and has already been debunked here, but perhaps dbstealey can fill us in on the details and provide perer-reviewed references.
joelshore says:
Thanks, dbstealey, for further lowering the discourse by pasting graphs from the right-wing propaganda website… &blah, blah, etc.
As usual, joelshore is out to lunch. Instead of debating science, he attacks the provenance of the graphs I posted — just another type of the discredited ‘Appeal to Authority’ fallacy.
In fact, those graphs came from here. There are lots of other graphs there, too.
These graphs show the same thing; humidity is declining:
Shore constantly inserts his far-Left politics into science discussions. Graphs of humidity are not “propaganda” — except in the minds of deluded numpties who still cannot admit they were flat wrong about man-made global warming [MMGW].
If there was real global warming happening, there would be more evaporation, and humidity would rise. But humidity has been declining for decades — another piece of real world evidence that debunks the MMGW scare that is still being purveyed by the alarmist cult.
Yes, dbstealey, we all know that you got that data from Ken Gregory of the Friends of Science, just as I said. Now, you are going around and finding this same debunked data ( http://geotest.tamu.edu/userfiles/216/Dessler10.pdf ) plotted on different websites.
That’s what fake skeptics do: They uncritically accept a debunked piece of data that supports their point of view and ignore the mountain of better data that refutes it.
joeldshore, from the Dessler et al paper:
Based on the available evidence, it is our judgment that negative trends in the tropical mid and upper troposphere in response to long‐term climate change are spurious. This is clearly the most parsimonious explanation, and it is in accord with virtually all of the independent lines of evidence (models, observations, theory, and newer reanalyses). Clearly, however, our analysis emphasizes the need to understand and reduce the uncertainties in long‐term trends from reanalyses, and this goal should be a high priority of the community.
That is not a “debunking” of the humidity declines, but a different theoretical interpretation based on models, some of which are known to be unreliable. He does not actually define “spurious”, but it usually refers to something in the data that is independent of the most interesting cause being studied.
joelshore says:
Yes, dbstealey, we all know that you got that data from Ken Gregory of the Friends of Science, just as I said.
“We all know”??
What a deluded jamoke. As I plainly stated, I copied those charts from WUWT, “just as I said” — proving that joelshore is a know-nothing.
More nonsense:
That’s what fake skeptics do: They uncritically accept a debunked piece of data that supports their point of view and ignore the mountain of better data that refutes it.
…says the Numpty who has no data or charts of his own to counter the evidence of declining humidity. Shore emits psychological Projection like it’s coming out of a firehose. Everything is political to him; his ‘science’ is only a thin veneer of baseless assertions, as we see right here.
joelshore is the quintessential guy who could never make it in the real world. He only gets by in a tenure-protected ivory tower of like-minded fools. The government .edu establishment is a national disaster, as anyone can see who reads the papers. The reason is clear: it is populated and controlled by fuzzy-thinking Leftist chumps, who have been trained with grant funds the same way that Pavlov’s dogs were trained with dog biscuits.
Joel, the combustion of hydrocarbons generally produces twice as much water as CO2. So while there is great hue and cry over human CO2, nobody seems to even consider human water emission of twice as many molecules. In a microclimate setting (like airport thermometers) this seems far from insignificant.
So in the deserts the well mixed and well heeled “forcing” GHG seems unable to produce Jack DLR on its own. Explain why I should believe the second string “feedback only” GHG needs any help from this pitiful “forcer” in the humid areas?
dbstealey says:
Let me help you out by reading the first line of the WUWT page that you linked to: “Guest post submitted by Ken Gregory, Friends of Science.org”
I don’t present charts that I don’t understand from strongly-ideological sources, removed from all their context so that people can’t even tell where the data originally comes from. Instead, I link to the peer-reviewed papers on the subject, which is what I have done here. I will refresh the relevant links here for your memory (and adding the one that Sturgis kindly provided):
http://www.sciencemag.org/content/323/5917/1020.summary
http://www.sciencemag.org/content/310/5749/841.abstract
http://geotest.tamu.edu/userfiles/216/Dessler10.pdf
http://www.pnas.org/content/111/32/11636.full.pdf
You can find more by looking at the references of those links.
gymnosperm:
I’ve already explained why this is basically insignificant on the global scale. It might have some microclimate effects, although even those are limited by many factors…such as the fact that the effects tend to be logarithmic in concentration, which means that it is fractional changes in concentration that matter and since the concentration of water vapor is higher, it takes a much larger quantity of water vapor to, say, increase the fractional concentration by 10%.
And, you know this how? I see nothing in Willis’s data that shows you how much DLR is produced in the deserts. Yes, it is down by 50 W/m^2 or so from wetter areas but my guess is that it is still quite significant, given that the average amount of DLR globally is about 330 W/m^2 ( http://www.cgd.ucar.edu/cas/Topics/energybudgets.html ).
Because physics tells us that in the absence of the non-condensable GHG’s, the atmosphere would be enough colder that there would be significantly less water vapor in it (which would then make it colder still). And, if you don’t believe in the water vapor feedback when you go up in temperature, you have to believe in it when you go down in temperature…since you would end up with more water vapor in the atmosphere than it can hold when fully saturated if you try to insist that water vapor concentration does not decrease as temperature decreases.
Joel, last night my IR thermometer measured a zenith temp of ~-70F, with an air temp of about 20F, and it just clouded up with an air temp of 42F and zenith temp of ~ 33F. What’s the forcing in W/m2 of the sky compared to your 300 some?
matthewrmarler says:
If you can get beyond the fact that the mentioned the (apparently for you guys) evil word “models”, you’ll see that, as he says, the conclusion is based on “independent lines of evidence (models, observations, theory, and newer reanalyses)” and all of this is explained in the paper. It’s an extremely thorough debunking.
Anybody who accepts that one reanalysis with all of its deficiencies and ignores the wealth of data and other evidence that goes the other way is doing not for any valid scientific reason but rather because that one reanalysis tells them what they want to believe.
joelshore says:
I don’t present charts that I don’t understand…&blah, blah, etc. So he doesn’t understand? Everyone else does.
Followed by the usual “ideology” comment, which make his comment political — not scientific. As usual.
And why would joelshore argue science, anyway? He’s already lost that debate, faced with the fact that humidity is declining.
–This one was funny to me because it was such an excellent and detailed map of the desert and arid areas of the planet. —
It doesn’t seem to show the desert of Antarctic. And the State of Washington
is fairly wet. And Seattle, Washington and western part of BC Canada are temperate rainforests. And generally poleward regions are drier.
But mainly I wonder about the Antarctica:
“To be considered a desert an area must have less than 250 millimeters of annual rainfall. Using that criteria, the continent of Antarctica is the largest desert on Earth. It has less than 51mm of precipitation per year and little or no vegetation.”
http://www.universetoday.com/73868/what-is-the-largest-desert-in-the-world/
Willis seems to have assumed 100% relative humidity in the formula, which is probably reasonable for Antarctica, but shows as a discrepancy for warmer deserts.
No relative humidity in Brunt’s formula.
“No relative humidity in Brunt’s formula.”
Yes, there is. He refers to water vapor pressure, but that is clearly the actual partial pressure. Here is Table 1 from his 1932 paper:
http://www.moyhu.org.s3.amazonaws.com/misc/bruntwv.png
p is the pressure he uses. If you look at the top number, it clearly isn’t sat wv. At 30°C that would be 32 mm Hg, not 16. So RH is 50%.
Still that doesn’t explain the discrepancies. If Willis uses 100% RH that means that he will get the maximum possible value for NLM according to Brunt’s formula and that the Ceres values should all be identical to or lower than the Brunt values. That clearly isn’t the case. More likely he used Brunt’s actual values (which seem to imply 50 % RH). In which case this seems to be a neat method to determine the RH on a global basis.
“Still that doesn’t explain the discrepancies. “
Well, there’s more. Willis says Brunt’s formula is
“The Brunt method estimates the “effective emission” as a function of the form
a1 + a2 * vapor_pressure”
But it is actually
a1 + a2 * sqrt(vapor_pressure)
That is going to create a few discrepancies.
Nick Stokes March 29, 2015 at 2:11 pm
Thanks, Nick. The calculation was done properly, but the description in the head post was not. I’ve corrected it.
Regards,
w.
I notice that you didn’t address my actual point.
It is cute to include the polar regions as deserts but rainfall amount as a criterion was intended only for arid hot lands because the features we have come to know about the hot kind form under these conditions. It would be ridiculous to lump the polar regions in with the hot deserts because, excluding the oceans, these places have more water than anywhere else on earth. The radiometers in the satellites haven’t been let in on the joke, so they don’t get it. Also, 100% humidity occurs in pretty dry air only if it is exceedingly cold (based on the definition of relative humidity).
“It doesn’t seem to show the desert of Antarctic. And the State of Washington
is fairly wet. And Seattle, Washington and western part of BC Canada are temperate rainforests.”
Look more closely. Washington state east of the Cascades is not wet. It is part of the Great Basin and semi-desert.
“But mainly I wonder about the Antarctica”
Note that the map shows differences in absolute DLR. DLR is very low in Antarctica so even a large percentage error there will be fairly small in absolute terms. Still, much of East Antarctica shows “near desert” error.
Since there’s discussion of what constitutes a desert and gbaikie has invoked the term “temperate rainforest” for Seattle and western BC, I’d point out that much of the west coast is a lot less rainy than many think.
Seattle’s annual rainfall is around a meter (40″). Vancouver 1.2m. The appellation ‘rainforest’ typically calls for a minimum of 2.5m of annual precipitation, and it should occur fairly uniformly through the year. That is not the West Coast; there are 4 distinctly dry months.
Forests of any kind don’t seem to thrive where there isn’t decent rainfall as evidenced by the 25cm in southern BC, east of the Coast Range (as you point out,tty); sage brush and scattered pine.
Actually You can’t put a fixed rain figure on “rain-forest”. A lot depends on the temperature (=evaporation). And a short dry season is not unusual in rainforest areas, check Manaos for example. In North America temperate rainforest climate is usually defined as >1400 millimeters rain with a mean annual temperature between 4 and 12 degrees Celsius. This means that places like Seattle, Vancouver or Olympia, which are all in partial rain-shadow do not quite have temperate rainforest climate, but the western side of the Olympics and Vancouver Island most definitely has!
gbaikie says: “And the State of Washington is fairly wet.”
Actually, it is only the western half that is wet. Most of the eastern half gets under 20″ per year, with a part of the region getting less than 10″ per year: https://content.lib.washington.edu/cmpweb/resources/map-rainfall.html
( “Willis Eschenbach
March 28, 2015 at 1:40 am
Thanks, Wicked. We’re looking at clear-sky conditions in the map above (no clouds). Desert areas get very hot during the day because they don’t have many clouds. The effect of this is much larger than any decreases in daytime downwelling longwave.
And they get very cold during the night because there’s little water vapor to absorb radiation and leave the earth warmer.
So no, they don’t say much about the greenhouse effect.” )
Sorry Willis, but Wicked is correct, deserts say EVERYTHING about the greenhouse effect !!
In simplistic terms ( so CAGW devotees can follow the logic) –
We are told, Ad infinitum, that CO2 is the main cause of global warming via Infrared reflection etc…….
It is agreed that CO2 is fairly evenly-ish mixed in the atmosphere around the globe.
So if CO2 is the main culprit, deserts would stay warm at night…but they don’t…unless there are clouds
Therefore a simple proof that CO2 is not the main driver …but cloud is THE greenhouse gas.
Sarc on-
To save the world from imminent destruction, we urgently need a way that politicians can make serious personal fortunes by taxing poor people for creating water vapor !! – Sarc off.
micro6500
March 28, 2015 at 1:44 pm
“Right, surface stations show no real change in rel humidity (~69-70%), and no loss of nightly cooling.”
A good reason for this away from the effect of the oceans (where most stations are), it seems to me, is that if you have humidity in the day near the above levels, the dew point is reached at some time in the night and water is forced out of air as droplets on the vegetation. When the sun comes up, it just re-evaporates most of the same water back into the atmosphere (some of which has been taken up by the vegetation as it slips down to the roots) and adds some more from evapotranspiration. It seems one could calculate what the likely daily relative humidity average should be knowing the diurnal temperature variation and knowing that nighttime is ~100% humidity before dawn in the temperate zone. Add and subtract deserts, tropical zones and the rim of ocean affected land. A simple (simplistic?) model to be sure. Were I to have been asked to guess the figures, I would have said roughly around 70%.
And if I could figure out how to link the jpg of my weather station you can see how the average temp increases in the spring until it maxes out rel humidity on the high side in the summer, and the low side in the winter.
I would have never guessed it did this even though I knew of all of the individual effects.
[Reply: Just post the link, separately. It has to end in .jpg or .png or .gif to appear. Otherwise, readers will have to click on the link. ~mod.]
Micro,
I hope you are able to post some graphical form of your humidity data. I have been watching intently with regards to the ~ 80% RH you have observed and commented on.
I don’t have a graph, but I do have the data. Now this is a straight average of stations that had at least 360 samples per year, but it isn’t weighted for distribution of stations and it probably should be.
But the data includes dew point, I calculate Rel Humidity
YEAR DEWPOINT RELH
1940 40.56682644 75.34768165
1941 44.24091639 74.97565368
1942 44.45971805 71.45144152
1943 48.52910657 68.21156434
1944 47.20622234 68.58368678
1945 48.92415329 70.02185462
1946 46.15443042 71.94139546
1947 44.61259741 70.85602068
1948 44.4461462 69.10623409
1949 43.74718298 68.89516838
1950 43.04368306 69.42639585
1951 43.86450442 69.32324362
1952 42.81918995 67.84774625
1953 44.66486394 67.82353649
1954 44.74067333 68.41008572
1955 44.97189331 69.33341908
1956 44.32255233 68.67325051
1957 44.88539286 69.36450976
1958 44.54795943 68.15226773
1959 43.90947345 68.17989382
1960 43.20859712 68.02032403
1961 42.49861668 68.96802513
1962 41.98599219 69.00100279
1963 41.61687443 68.71413467
1964 41.50618815 68.02378888
1965 41.49677782 68.43474935
1966 40.55561334 68.54323846
1967 41.51172772 69.03934749
1968 41.08154826 68.15801744
1969 38.29465457 69.28906119
1970 35.09911457 69.28693236
1971 43.25642281 66.0854363
1972 43.42498767 66.80676248
1973 42.97526167 69.31133555
1974 41.02287683 70.27566127
1975 38.82723865 69.58104188
1976 38.16243391 69.30562984
1977 40.65054845 68.85577927
1978 39.78448988 70.22669152
1979 40.14715555 69.79472106
1980 38.77878518 69.88084667
1981 40.31178052 69.57833066
1982 40.54020181 70.71218634
1983 40.64922774 70.74111249
1984 40.02106401 70.4694655
1985 38.69228449 70.99691469
1986 39.49661508 70.62265641
1987 39.6419206 71.08693085
1988 39.46636274 70.27924484
1989 39.79061357 70.86782886
1990 41.27510356 70.69013438
1991 41.31413254 71.14807546
1992 41.44899262 70.18820229
1993 41.66703505 70.11676981
1994 42.43282258 69.70913829
1995 42.85852681 69.6589601
1996 43.00022387 70.24634663
1997 43.58569476 70.1466172
1998 44.27042243 70.58096154
1999 43.56819776 69.96230073
2000 43.37874393 70.31183227
2001 43.23721187 69.85904807
2002 43.37056012 69.80694885
2003 43.16938149 69.59319163
2004 42.93039789 69.55653173
2005 42.71627221 69.01247888
2006 42.63294836 68.89994799
2007 42.8232091 68.5272092
2008 42.16064641 68.82682172
2009 42.62356904 69.51095147
2010 42.41952692 69.47312855
2011 43.08406857 69.29540385
2012 43.42689236 68.27844709
2013 43.23127161 69.0916613
9999 is an average of all years.
9999 42.37539614 69.58612645
Joeldshore are you saying the ratio between natural and anthropogenic C02 is decreasing with anthropogenic being the driver?
Willis, your maps even indicate the Taklamakan Desert, which is high and cold. Very interesting analyses and map. It appears to be better at indicating desert areas than the sinking hot air at about +/- 30 deg.
I too love color maps and the eye can find much information in them.
What, after reading all comments (some of which I can follow, others not so much) is as far as I can tell nobody seems to include the geographical features of our planet that help create deserts without doing a thing . They just kinda sit there, you know the Rockies, the Andes, Alps, Himalayas etc. The rain shadows they create have as much (if not more) to do with all the things I have read on this thread regarding deserts so far. (call me stupid). You all can talk about solar this, gases that reverse heat radiation etc but as far as I have experienced for decades as a farmer I look up at the mountain ridges and tops and they tell me more than a $100,000 a year weather guy
Rain shadow is important for some deserts (e. g. Takla Makan, Kyzyl Kum, Gobi, Great Basin), but not for others, that go straight down to the sea-shore (Sahara, Atacama-Nazca, Namib, Rub al’Khali).
asybot,
I think I may be in the same or similar boat as you. A lot of most valuable understanding (e.g. large desert regions) may be being lost due to annual means and the likes. Large desert areas may be much influenced due to the lack of convection due to water vapor at low levels. But then that could be caused by the Hadley (hope I got that right) circulation pattern. I believe that the data needs to be reviewed in the desert regions on a much shorter time scale to get a better understanding.
Willis’s emergent thermostatic hypothesis in the tropics seems good to me. Solve the deserts and we may be closer to reality. Since the ‘global warming’ meme started there has been too much misdirection from the ‘believers’ but those days are numbered.
BTW, I see WUWT has passed the “one quarter of a billion” views this past week. There are a lot of real people looking at the real issues.
Great – a ‘desert finder’!
reproduceable, falsifiable.
real world measurment of DLR + a robust, empirical backed formula.
Thanks, Willis – Hans
Nice work, Willis. Some time ago you spotted an error in a paper and corrected it. The author was furious that a mere non-scientist had the nerve to correct him. TS, I thought It is this attitude that makes their “climate” science accumulate a pseudo-scientific dogma that cannot be changed by the logic of science. If there is a breakthrough I expect it from people like you, not from these academics with outsized egos. Keep up the good work.
Once again I get to enjoy a Willis piece.
From some of the comments from others about “Well mixed CO2” I get the impression that your look at CO2 around the world still hasn’t sunk in yet. CO2 isn’t well mixed. There are definite highs and lows around the world. It isn’t quite like water vapor though, the delta between high and low values isn’t as extreme.
Here’s my weather station’s rel humidity and temp.
Where are you located?
N41 W81
35 miles south of Lake Erie.
Thank you for another interesting post.
Kristian March 29, 2015 at 11:38 am
Mmm … thanks, Kristian, but I fear you and wickedwf are oversimplifying. The great global desert belts have a variety of physical differences from “tropical/subtropical rainforest and generally wet areas”. These include:
• Descending dry air. The great Hadley cells are driven by the tropical thunderstorms. These move air upwards, wring out the water, and send it poleward. This dry air descends at about 30° north and 30° south, and it is the reason for the existence and the location of the desert areas.
http://wattsupwiththat.files.wordpress.com/2009/06/willis_image1.png
The existence of this global belt of descending dry air has a variety of knock-on effects:
• Fewer clouds. Because the descending air is dry, there’s little moisture in the arid areas to form clouds. This allows a much larger amount of the solar energy to make it to the surface, which leaves the desert area warmer than it would be otherwise.
• Less absorption of solar energy by water vapor. In clear-sky conditions, about 78 W/m2 of incoming solar energy is absorbed by the atmosphere (CERES data). Somewhere around half of this, call it 40 W/m2, is due to absorption by water vapor. So the dry air allows more solar energy to make it to the surface.
• Less vegetation. This has two effects. First, plants absorb solar energy and convert it to chemical energy. So a lack of plants allows for greater peak temperatures. Second, plants pull water up out of the soil and evaporate it (transpiration). This cools the area.
• Drier soil. This has three effects. First, it directly reduces thermal mass, which allows for greater peak temperatures. Second, it reduces soil heat conduction. This has the effect of reducing the thermal mass involved in daily temperature fluctuations, and again leads to greater peak temperatures. And third, it reduces direct evaporation from the soil. This prevents evaporative cooling.
Note that all of these effects are due to the lack of water. As a result, the 30° north/south belts of dry descending air have little effect over the ocean (see Figure 1).
In any case, those are some of the reasons for the differences, there are others. As a result, it is by no means a simple referendum on the greenhouse effect.
My best to you,
w.
So water vapour acts as an anti greenhouse in the tropics and subtropics, it reduces maximum daytime surface temperatures. There are temporal and spatial claw-backs by means of the heat capacity of WV to the night time, and by advection to higher latitudes. And the whole system is set up to gather more solar near infrared in the horse latitudes, and with atmospheric rivers delivering strong water vapour warming to higher latitudes, biased towards the winter hemisphere. But what is the net balance?
Surface stations, when you look at yesterday’s rise and last night’s falling temps, over a year it’s slightly negative (more cooling).
We all know about these other effects, Willis. That’s exactly the point. You cannot under any circumstance look at a radiative budget alone and determine sfc temps. Not regionally. And not globally.
The rGHE hypothesis seeks to derive directly the temperature of the surface purely from an atmospheric radiative balance (the lapse rate down working only as its extended arm). You get nowhere with such a simplistic approach. You will only fool yourself.
The total energy content (the ‘internal energy’) of a thermodynamic system – like the Earth system – is certainly determined by the balance between its total energy input and output, in the context of the Earth system, simply the balance struck between SW IN and LW OUT through the ToA. Energy content is an extensive property.
However, the specific temperature (an intensive property) of different subsystems inside the overall system can by no means be derived from this same balance/imbalance. The tropical dry/wet region comparison is a good case in point. This is where the rGHE hypothesis goes wrong. Internal temperatures would be set rather by differing ‘heat capacities’ and ‘internal movement’ of energy. The internal movement of energy between the subsystems inside the Earth system is governed almost exclusively by the process of convection/advection.
Kristian said:
“Internal temperatures would be set rather by differing ‘heat capacities’ and ‘internal movement’ of energy. The internal movement of energy between the subsystems inside the Earth system is governed almost exclusively by the process of convection/advection.”
Exactly right. Note though that both KE and PE are energy but only KE is heat.
So you have to, somehow, get convective overturning to raise surface temperature above that predicted from the purely radiative S-B equation.
What suggestion do you have other than the description of adiabatic processes that I have already put forward ?
Either it must be radiation as per AGW or it must be atmospheric mass acting via adiabatic warming on descent and Willis’s findings are consistent with the latter but not the former.
Again, low RH, dry, does not mean low DLR. Above the Sahara there is appr. 380 W/m2 SW ‘available’ at TOA but at the surface net SW is only 170 W/m2, enough to keep the surface at -40 deg C. DLR is twice the net SW. The Saharan atmosphere is absorbing more than 100 W/m2 solar, much more than the global average, so stop this dry air misinformation.
CERES-plots here: http://virakkraft.com/Sahara-rad.pptx
LGL
The issue is not the absolute amount of DLR because however much DLR there is the thermal effect at the surface gets negated by convective adjustments along the lapse rate slope which is determined by the density gradation as one moves upwards. That density gradation being a consequence of the kinetic energy of the mass of the atmospheric gases doing work both with gravity on descent and against gravity on ascent.
The issue is that regions with more GHGs do not warm as much as regions with less GHGs. Under AGW theory that is impossible.
Stephen
Wrong again.
http://virakkraft.com/Temp-rad-vapor.png
Now where is the correlation? Temp and PW/DLR or Temp and Net solar?
And atmospheric physics is not something AGWarmists invented. It was established science long before they arrived. Stop joking .
lgl
Those charts simply show that the tropics are warmer than other latitudes.
In Willis’s version one can see clearly that there is less DLR over deserts and there is no doubt that sunny deserts become warmer under insolation than humid regions.
You need to show the land surface chart to reveal that which is probably why you didn’t include it. That omission makes me doubt your integrity.
lgl,
I wonder what the specific’s for those are. my experience with measuring SW IR is that when pointed straight up the temp measured is greatly dependent on the amount of water in the air, air temp and ground temp.
Dry air overhead on a clear cool to cold day is very cold, -40F to < -70F, a 60F – 70F day with 60-70% rel humidity can be from 32F to 0F, cloud bottoms are 10-20 colder than surface temps, as much as 90F warmer than clear skies. The attribution of that SW is critical.
So, while an all-sky reading when it's cloudy will have a very high SW flux, Clear dry skies there is far less SW flux, which is what Willis's chart shows.
And TOA is a redherring, we live down here, and we have no past measurements prior to the 60's-70's to know what it did in the past.
micro
I can’t tell from your writing but if I am to speculate you mean LW IR and you are using an IR thermometer in the 8-14 micron band, which is mostly within the atmospheric window, in which there is not much radiation from clear sky (but a lot from clouds) so the temp you are reading does not tell you much about the total LW.
Regarding Willis chart I think all he has shown is that there is no globally valid Brunt formula, and that people working in this field already knew that.
Yes, I did mean LW.
Actually 8-14u is part of the main BB spectrum for environmental temps. So this should be right in the middle of the hole to well very cold temps. But this is what the surface see, You really need to add the energy in the 15-16u Co2 spectrum to this, but I think this can be calculated and then added to the rest of the skies LW IR flux.
Water absorbs in the 8-14u spectrum that shows up nicely.
When you get down too it, anthro Co2 isn’t a lot of forcing, and compared to the energy spent regulating rel humidity, Co2 doesn’t seem to impact night time cooling, and if it’s not restricting cooling it’s doing nothing to surface temps.
Stephen
So your theory is invalid for 70% of the surface, nice to know. I didn’t use the JMA temp diagram because it goes in 5 deg steps. If you have one with 1 deg resolution I’ll be happy to include it. Anyway, much of the deserts are quite chilly on average because of high altitude and can not be compared to sea level.
The point was that temperatures get highest over deserts where GHGs are lowest contrary to AGW theory.
You have, presumably deliberately, declined to show a land surface temperature chart which, when compared to the sea surface temperature chart would show the difference between lower sea surface temperatures beneath large amounts of GHGs (water vapour) and higher land surface temperatures beneath small amounts of GHGs (low humidity).
micro
“Water absorbs in the 8-14u spectrum that shows up nicely”
Ehm.. not much
water alone will probably give you less than 220K in a 285K atmosphere.
http://virakkraft.com/Modtran-VW.png
I prefer this
http://webbook.nist.gov/cgi/cbook.cgi?ID=C7732185&Units=SI&Type=IR-SPEC&Index=1#IR-SPEC
So water vapor is under reported as well, even though I think with a weather station you can sort that out as well.
But, let me say this again, when you compare anthro Co2 to all of the other LW IR it is swamped by the other sources, and I think when you look at the energy bounded by water processes, I don’t think Co2 can do much.
Stephen
There is no “contrary to AGW theory” in this. (and is is standard GH theory, not AGW theory)
I have told you, there is 170 W/m2 SW and 350 W/m2 LW to the Saharan surface. What more do you need to get the 30 or 35 C or whatever the average is? (Also remember the emmisivity there is somewhere around 0.9) Of course there are hot regions in some deserts, hotter than the ocean, and Willis has told you why, lack of water. Nobody has denied that.
lgl
The DLR to the Saharan surface has no thermal effect due to the lapse rate.
The absence of water for evaporation is not relevant for the S-B equation.
The heat that develops above S-B is due to the restraint on convection beneath the descending air column.
Stephen
What’s your data on ” heat that develops above S-B”?
lgl
Please try to see it.
The average temperature of the Earth’s surface is said to be 33C warmer than predicted by the S-B equation.
AGW theory attributes that 33C to DLR from radiative gases.
I say it is a consequence of descending air warming adiabatically (50% of the atmosphere is descending at any given moment) restraining convection from the surface below the descending column so that the surface rises 33C above S-B overall. The effect is just like a greenhouse as I explained before but a result of mass and not radiative capability.
If radiative gases are present they radiate energy to space from witrhin the atmosphere which leads to less total energy (KE plus PE) in the descent leg of the convective cycle than was present in the ascent leg.
That reduction in total energy in the descent offsets the potential surface warming from DLR so DLR fails to have any net thermal effect at the surface.
The lapse rate slope determines the amount of convection needed to keep radiative energy in from space equal to radiative energy out to space and the lapse rate slope is set by the density gradient of atmospheric mass which results from gravity acting on total atmospheric mass. The more mass or the stronger the gravitational field the denser the air at the surface and the greater the proportion of incoming radiation that can be taken up by conduction and convection. Once that energy has been absorbed by the mass of the atmosphere it cannot be radiated out to space. Instead it is held as PE (not heat) in the molecules suspended off the surface and the higher those molecules the more PE they carry relative to KE.
Density at the surface is critical to surface temperature because density determines the proportion of incoming radiation that can then be transferred to atmospheric mass by conduction and convection.
The rate of decline of density with height is critical to the lapse rate slope because that rate of decline determines how much of the conduction from the surface to the lowest air molecules can then be moved further up by conduction.
If anything other than mass density tries to alter the lapse rate slope then convection changes to neutralise it by changing the relationship between total energy involved in the ascent and total energy involved in the descent.
If there are no radiative gases energy in the ascent equals energy in the descent.
As one increases the radiative capability of the atmosphere then energy in the descent reduces relative to energy in the ascent to keerp surface temperature stable and the radiative balance with space stable.
If the atmosphere were 100% radiatively efficient then all energy from the planet would leave to space from within the atmosphere and none from the surface but that can never happen as long as the gases comprising atmospheric mass can conduct and convect.
Conduction and convection create a PE rerservoir within the atmosphere that is called upon (or not) as necessary to maintain thermal stability as long as insolation continues.
Note that this only applies to gases and not liquids or solids hence the need for the Gas Laws.
… and, what does the Saharan surface know about the lapse rate? The 350 watts is hitting the surface. How can the surface avoid absorbing it?
As a reference, you give “Estimation of Daylight Downward Longwave Atmospheric Irradiance under Clear-Sky
and All-Sky Conditions”
http://journals.ametsoc.org/doi/pdf/10.1175/JAM2503.1
which claims
However, the provided equation is nonsense – it most definitely is NOT one of the Magnus equations. (There are several.) Here are 2 equations, one provided by the paper and the MagnusTetens equation.
At 300K (88.33F), the paper’s equation gives a saturation vapor pressure of 10.9 mBar, and MagnusTetens gives 35.3 mBar – not even close!! Though there is no universally accepted formula to determine this, the correct value is somewhere between 35.2 and 35.4.
Unfortunately, I have no way of determining if the paper has an error, or if the error is in Guyot 1997. However, either way, that paper should have never made it thru peer review!
For details on about 30 formulas for calculating saturation vapor pressure, please see my web page. I also provide 2 programs (in a zip file) that you can use to help understand the problems.
Bookmarked for LW radiation calc’s.
Robert Clemenzi March 29, 2015 at 9:59 pm
Interesting work!
Maybe you might be interested in helping me with something, your line by line spectrum program, I’d like to take the measurement from my IR thermo which is calibrated to a BB with some emissivity that can be set. But I know that BB has a big spike from Co2 that needs to be added to get a more accurate flux, that Co2 “spike” should be able to be calculated by a program such as yours. An app that anyone could use that would take maybe air temp and the sky temp in IR and tell me how much more flux has to be added for Co2 along both natural and anthro. I think it would be beneficial to see how much IR is actually from Co2.
If not, maybe you can point me to enough info that I could create it maybe from your analyzer.
micro6500, that is a difficult problem. None of the specs I’ve seen specify the frequencies used by IR thermometers. As a result, I just assume that they cover the entire spectrum, but that might be wrong. At any rate, using my line-by-line program, at 15C (59F), for a path of one meter, CO2 emits 2.37 W/m2 and water vapor at 60%RH emits 32.2 W/m2 with insignificant spectral band overlap. The blackbody emission for the same temperature is 390 W/m2. Therefore, for measuring the temperature of items only an inch or two away, these gasses are ignored.
Of course, the CO2 and water vapor emissions are greater over longer distances. My program uses a default of 1,000 meters yielding 54.5 W/m2 for CO2 and 207.4 W/m2 from water vapor with about 20 W/m2 of spectral overlap.
When pointing the thermometer toward the sky, I assume that an IR thermometer absorbs all the available IR radiation and indicates the temperature expected from a blackbody only one inch away. (The apparent or equivalent temperature, not the actual temperature.) As such, no “correction” is needed. To find an “actual” temperature, put the apparent temperature into the program and find the associated blackbody emission. (The program uses Stefan’s equation.) Then modify the temperature until the atmosphere emits the same amount. This will be very approximate, mainly because the temperature of the atmosphere changes in an unpredictable way with height.
For example. if the IR thermometer reads 0C, that corresponds to a blackbody emitting 315 W/m2 with an emissivity of one. Using the program defaults, for 1km of atmosphere to emit the same power, its temperature must be 35C (95F) at 18%RH and 29C (84F) at 60%RH. If you change the assumed thickness to 2km, you will get 25C (77F) which is still a bit too high. However, if you change Alpha multiplier (on the Tools tab) from 200 to 20,000 (which makes the program way too slow) then the atmosphere temperature becomes 20C (68F) which is closer to what I observe. (Whether or not this large Alpha multiplier is really more accurate is beyond all the references I have access to.)
It has a 8-14u filter over the sensor. As for distance it has a 10:1 (iirc) distance to field ratio, since I can measure clouds my distance is pretty far.
I’ll have to check your link out tomorrow. , thanks!
Robert Clemenzi commented
I think most of the hand help ones have a filter of 8u-14u, the open window in the atm, so mine seems pretty accurate from over 30′ away, and differences I attribute to changes in spot size with distance. I read your GHG paper, and I think you’re going the right way, but you need a IR thermometer like mine (plus then you’ll have a vested interest in the calculator I need), but you’re neglecting the heat in the ground, at night it(dirt, brick, concrete, asphalt) is warmer than the sky and air temps (clear day night cycle), grass however is colder that air temp.
I think when combined with surface temp data you could calibrate this. For instance you can measure the Tsky temp, see the rate of temp decrease, and something I’ve found is that when the rel humidity rising into the 80’s and 90% range (as the night cools) cooling slows down, even though the Tsky hasn’t changed. So the rate of cooling changes during the night, the cause of this should be able to be simulated. And there’s a lot of data that restricts the output.
I was looking for the code you use to calculate the H2O and Co2 flux, but I couldn’t actually find it, can you point me to what I’m looking for?
BTW, I have lots of surface data that you would find useful. I’m looking at the rate of change by day, by year, and by area on temps, and part of that is the forcing, I’m adding solar forcing for each station to my code now, I figure I have what was at toa prior to albedo changes, and I can see what the temps do, should be interesting, then if I can add co2 and h2o to the mix based on air temp and forcing, sound like something to learn.
here: http://sourceforge.net/projects/gsod-rpts/
If you had better data, I think you would find that the ground cools much faster than the atmosphere. Unfortunately, you will need balloons to personally collect that data, or you can get the data online.
I have written a Lapse Rate Animation program that plots a year’s worth of data in a way that helps to understand the reality. I strongly suggest looking at the SouthPole data. (Notice that the actual SouthPole data differs from what the text books say!)
BTW, I like your sourceforge plots.
@Robert Clemenzi
When I say air, I’m meaning 2 meters, since you mentioned balloons, that air temp goes down and then up.
But, when we’re told of catastrophe, the only reason they would talk about the troposphere is because the surface isn’t behaving.
But if you measure the temp of a concrete sidewalk, or the dirt between patio bricks and the air above it, or the grass besides it right before Sun up, it’s still warmer than both (at least is has been for me). Maybe with short days, it might get non-linear.
Michael 2 commented
This is both where I was coming from (that physical contact would normalize molecular temps and my IR thermometer could detect it) and where I’m going(that the bulk of the atm doesn’t actually cool by itself).
But it explains the various bits of data I have and, I was going to say trust, but understand might be a better word.
But we have a pretty detailed log of the response to the days solar energy as it changes through out the year.
micro6500 says
No, they look at the troposphere because their theory says to. However, their theory has a serious error which explains why their predictions will never come true.
I am a bit confused by the rest of your post – too many pronouns. Basically, in the morning the ground is significantly colder than the air a hundred meters above it when measured with a thermometer (assuming no wind). Two meters is not high enough to be above the morning “fog” layer which limits how cold the ground can become.
BTW, the *ground* temperature may be +/-20C (and sometimes more) with respect to 2 meters above the ground.
Robert Clemenzi commented.
I’ve only measured it colder in the pre-dawn morning, and warmer in the late afternoon.
You can see this “fog” reduce night time cooling, but only when rel humidity goes over ~80%, until then cooling rates are much higher.
I finally found a reference to the important parts of Guyot 1997 – on page 142
If that equation is converted to Kelvin, then it should be
From this it is pretty obvious that someone added when …
To be clear, the text book is nearly correct, but the paper .. it passed peer review and therefore qualifies as “climate science”. In addition, there are at least 12 references to it.
Hardware store infrared thermometers are sensitive to infrared in the “atmospheric window” meaning they are completely insensitive to carbon dioxide and apparently also water vapor. They do see the emission of liquid water droplets in clouds. This is easily demonstrated by point it at anything more than a few meters away, especially the clouds at night. If they were seeing CO2 you’d have a nearly uniform temperature measurement but mine goes to max-negative, -60 F, on a clear sky but typically +21 or so for clouds.
Michael2, that is like mine, 8-14u but water does show up there.
But when you measure -60F, that is the temp of that window to the surface. The full spectrum IR (pyrometers iirc) get more water, Co2 and the rest of the long wave IR and can make up for that, but I still point to that you can make ice on a clear dry night without air temps going below 32F.
Robert Clemenzi
I was thinking about the temp vs altitude chart, In relationship to the surface being warm compared to ground level air most of the year (at least locally), that the chart showing temps dropping as altitude goes up would be how the IR from the ground would penetrate surface air, brightly near the ground, and it would be attenuated by GHG’s over distance (up).
Now I understand (if I understand this at all) Co2 blocks all IR in far shorter distances than the minimum temp altitude, but I still thought it striking, and something I should say out loud, if nothing more than to plant a seed.
http://mc-computing.com/Science_Facts/Lapse_Rate/Lapse_Rate_Summer.html
Joeldshore, it might help you to remember the scientific question here. It is not incumbent upon the skeptics to knock your nonsense into a cocked hat, it is the burden of “your side” to falsify the null hypothesis with respect to climate change, i.e. nothing is happening that lies outside the parameters of natural variability.
Please locate and quantify the weather events you imagine lie outside the realm of our historical data set?
Until the AGW mob can satisfy that most basic of scientific principles, the null hypothesis holds, no?
Thank you Larry. When today’s wriggles are still within past natural variability, anything said about today cannot be significant. Period. End of statistical lesson. And please Joel, do not be showing spliced temperature reconstructions with modern observations to demonstrate alarming conditions. Apples and oranges. The fine scale of today, measured by averaging fine scale daily observations, cannot be captured in the reconstructions which do not use daily averaged observations.
And now a question. How is relative and absolute humidity at different atmospheric levels, collected and reported? Curious. Directly observed or calculated?
Pamela, NOAA uses balloons to measure the temperature and humidity at various altitudes. For high precision, humidity is determined using a chilled mirror to determine the local dew point which is converted to relative humidity using a model (an equation). As a cheaper alternative, they could use a calibrated humidity sensor. Since “the science is done”, I was surprised to find over 30 models (equations) to make the conversion.
Today myself and my good lady have been riding our harley in out back oz , it has an ambient temp gauge, we had the odd cloud that gave maybe a quarter of a mile shadow, every time in shadow the air temp dropped up to two degrees c. Strange that the temp drops so quickly with a sun shade.
I wish your comments weren’t closed on the Norwegian lifespan vs sunspot article but you might have some interesting data that would perhaps yield interesting results twisted a different way.
I ran some analysis on my own Norwegian ancestors and turned up an interesting thing — summer-born Norwegians have a lifespan distribution that peaks at 75 years of age (bins spaced 5 years apart) whereas winter born Norwegians had two peaks, one at 65 and another at 75. In other words it seems to matter what month of the year you were born as to lifespan.