Guest Post by Willis Eschenbach
Once again, the crazy idea that downwelling longwave radiation (DLR, also called infra-red or IR, or “greenhouse radiation”) can’t heat the ocean has raised its ugly head on one of my threads.
Figure 1. The question in question.
There are lots of good arguments against the AGW consensus, but this one is just silly. Here are four entirely separate and distinct lines of reasoning showing that DLR does in fact heat the oceans.
Argument 1. People claim that because the DLR is absorbed in the first mm of water, it can’t heat the mass of the ocean. But the same is true of the land. DLR is absorbed in the first mm of rock or soil. Yet the same people who claim that DLR can’t heat the ocean (because it’s absorbed in the first mm) still believe that DLR can heat the land (despite the fact that it’s absorbed in the first mm).
And this is in spite of the fact that the ocean can circulate the heat downwards through turbulence, while there is no such circulation in the land … but still people claim the ocean can’t heat from DLR but the land can. Logical contradiction, no cookies.
Argument 2. If the DLR isn’t heating the water, where is it going? It can’t be heating the air, because the atmosphere has far too little thermal mass. If DLR were heating the air we’d all be on fire.
Nor can it be going to evaporation as many claim, because the numbers are way too large. Evaporation is known to be on the order of 70 w/m2, while average downwelling longwave radiation is more than four times that amount … and some of the evaporation is surely coming from the heating from the visible light.
So if the DLR is not heating the ocean, and we know that a maximum of less than a quarter of the energy of the DLR might be going into evaporation, and the DLR is not heating the air … then where is it going?
Rumor has it that energy can’t be created or destroyed, so where is the energy from the DLR going after it is absorbed by the ocean, and what is it heating?
Argument 3. The claim is often made that warming the top millimetre can’t affect the heat of the bulk ocean. But in addition to the wind-driven turbulence of the topmost layer mixing the DLR energy downwards into lower layers, heating the surface affects the entire upper bulk temperature of the ocean every night when the ocean is overturning. At night the top layer of the ocean naturally overturns, driven by the temperature differences between surface and deeper waters (see the diagrams here). DLR heating of the top mm of the ocean reduces those differences and thus delays the onset of that oceanic overturning by slowing the night-time cooling of the topmost layer, and it also slows the speed of the overturning once it is established. This reduces the heat flow from the body of the upper ocean, and leaves the entire mass warmer than it would have been had the DLR not slowed the overturning.
Argument 4. Without the heating from the DLR, there’s not enough heating to explain the current liquid state of the ocean. The DLR is about two-thirds of the total downwelling radiation (solar plus DLR). Given the known heat losses of the ocean, it would be an ice-cube if it weren’t being warmed by the DLR. We know the radiative losses of the ocean, which depend only on its temperature, and are about 390 w/m2. In addition there are losses of sensible heat (~ 30 w/m2) and evaporative losses (~ 70 w/m2). That’s a total loss of 390 + 30 + 70 = 490 w/m2.
But the average solar input to the surface is only about 170 watts/square metre.
So if the DLR isn’t heating the ocean, with heat gains of only the solar 170 w/m2 and losses of 390 w/m2 … then why isn’t the ocean an ice-cube?
Note that each of these arguments against the idea that DLR can’t warm the ocean stands on its own. None of them depends on any of the others to be valid. So if you still think DLR can’t warm the ocean, you have to refute not one, but all four of those arguments.
Look, folks, there’s lot’s of good, valid scientific objections against the AGW claims, but the idea that DLR can’t heat the ocean is nonsense. Go buy an infrared lamp, put it over a pan of water, and see what happens. It only hurts the general skeptical arguments when people believe and espouse impossible things …
w.
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I have glanced at Slaying the Skydragon — well the free chapters. I was no especially impressed, and I have seen rather mixed reviews from others as well. It seems other long on philosphpty and short on math.
One particular statement that jumped out as I was jsut glancing again was:
“Backradiation would correspond to audio feedback ”blowup” between
a microphone and loudspeaker without amplifier energy input, which cannot
happen because inevitable losses prevents blowup without energy input.”
This seems like a complete mis-interpretation of “backradiation” to me.
PS I agree 100% that there is no “magic” associated with the GHE.
Bob,
I’m not being evasive about horizontal components — mostly running out of time.
In the end, we are looking at radiative TRANSFER of energy. To calculate the transfer from one region to another, we need a dividing line between the two regions and a calculation of the total flux passing thru that surface. That is exactly what I gave you. And exactly what Gauss’ Law gives you. One region is the ground (and ocean); the other is the atmosphere. The simplest case is to draw the line right at ground level. Then it is painfully clear that 390 W/m^2 is indeed leaving the ground and entering the air . The energy flying around within a region (eg horizontally) may be interesting in some ways, but is not part of the TRANSFER between regions.
Tim Folkerts says:
August 26, 2011 at 6:59 pm
At this point, we could discuss the EXTENT of the warming of the bulk due to an increase in the downward IR. IR might be inefficient at warming the oceans, but IR logically has SOME effect unless one or more steps above are incorrect. Perhaps 10 W/m^2 extra only warms the surface 0.01 K, leading to a 0.01 K increase in the bulk temperature to restore the gradient.
Hi Tim,
Other processes are swamping increases in DLR from extra co2. For example, it is estimated that OLR has increased some 6W/m^2 since 1948 (NCEP). That has been counteracted by increased insolation due to reduced cloud cover 1983-1998 of 4Wm^2 and who knoes what before. (ISCCP)
What is the evidence that DLR has increased at all?
If it has, then as you say, there could conceivably be a small increase in skin temp. I suggest this is a function of increased air temp, because rising ocean T is going to increase evap anyway. This is a very, very slow way to heat the bulk of the ocean. It’s not going to account for the rise in T of the top 700m that occured ~1980-2003 before the oceans started cooling again.
It’s the Sun shining through less clouds that did that mate.
Enjoy what’s left of global warming.
Myrrh says:
? What is it with you lot? What is so difficult to understand that this subject has been thoroughly investigated and it is known scientific fact that water is transparent to visible light, it does not absorb visible light, it remains unaffected by visible light. The science of visible light is optics
What is it with people who deny empirically measured quantities?
The coefficients of absorption were provided. They show how visible light is absorbed in water and changed to heat. That’s why deep sea divers take torches with them.
tallbloke says:
August 30, 2011 at 12:34 am
It’s the Sun shining through less clouds that did that mate.
————————————————————————————
Interesting sunshine hours and temperature charts at the Met Office re the last 80+ years in the UK.
“Rainfall, sunshine and temperature time-series”
http://www.metoffice.gov.uk/climate/uk/actualmonthly/
The UK – Annual – “Mean Temperature” and the “Sunshine Hours” appear to correlate very closely, sort of makes sense, more sunshine = warming, less = cooling? Admittedly a gross over simplification, but it is actual observational data.
Tim Folkerts says:
August 26, 2011 at 6:59 pm
“At this point, we could discuss the EXTENT of the warming of the bulk due to an increase in the downward IR. IR might be inefficient at warming the oceans, but IR logically has SOME effect unless one or more steps above are incorrect. Perhaps 10 W/m^2 extra only warms the surface 0.01 K, leading to a 0.01 K increase in the bulk temperature to restore the gradient.”
Tim, the ocean can cool even if the gradient decreases. Simply decrease the amount of SWR entering below the surface and you both cool the ocean and decrease the gradient. Any increase in water vapor reduces SWR reaching below the surface, (via spectral modification of TSI) despite the GHG effect on the atmosphere. Thus water vapor temporairly increases the energy in the atmosphere, while reducing the longer residence time SW energy entering the oceans, thus over time the overall feedback may be negative.
tallbloke says:
August 30, 2011 at 12:38 am
Myrrh says:
? What is it with you lot? What is so difficult to understand that this subject has been thoroughly investigated and it is known scientific fact that water is transparent to visible light, it does not absorb visible light, it remains unaffected by visible light. The science of visible light is optics
What is it with people who deny empirically measured quantities?
The coefficients of absorption were provided. They show how visible light is absorbed in water and changed to heat. That’s why deep sea divers take torches with them.
It’s pretty well meaningless when water is transparent to visible and doesn’t absorb it. Since water is transparent to visible and transmits it unchanged then whatever that is saying it can’t be saying that it is heating up the water when it says ‘absorbed’, or, there is something else happening.
That water is a transparent medium for visible light is a fact of real physics. It doesn’t get absorbed, it doesn’t get absorbed because water doesn’t absorb it. This is a physical known. It is what is. The process is understood.
That water ‘disappears’ at certain depths does not mean that it is being ‘absorbed’ in the technical meaning of this, that the molecules of water are actually taking in the energy. Because, water doesn’t. Water is a transparent medium for visible light. That divers at depth need to take a torch with them is supposed to disprove that??!!
For goodness sake.
What I am also saying is that the claim that the atmosphere is transparent to visible light is nonsense. Read the wiki on the difference between UV/Visible and Thermal – they are different from each other. They work on different levels. Light scattering in the atmosphere is a result of absorption – the molecules of nitrogen and oxygen absorb visible on an electron scale and send it back out again.
So, there are two things here. Prove that visible light from the Sun can actually heat water. And yes, you could try Tim’s LED… See how long it takes to get your bath up to a temp you can have a good hot soak in.. And, give me the amount of heat that is being generated in the atmosphere from the known physics of absorption of visible light, electronic transition, which results in reflection/scattering, since you claim that ‘absorption’ means ‘creation of heat’.
You really won’t understand what I’m saying until you think about this by actual properties and processes.
That you have bought into the AGWScience Fiction Inc.’s meme that Visible light is a thermal energy capable of converting to heat land and oceans, is not my fault. That you persist in reading every mention of ‘absorbed’ through that paradigm, is not my fault. That you keep rejecting what I’m trying to explain to you, is not my fault. It is my fault that I keep nagging at y’all to look at this objectively, I’m sorry you find it irritating.
I care about this aspect of the AGW con. It means that a whole generation of children now don’t understand the difference between Light and Heat. This is a controlled dumbing down of the population, just the same as the perversion of science by demonising carbon dioxide and the general postmodernism of ‘science is just another social construct’, where all scientific objectivity is denied in its postmodern reality and absorbed can mean whatever you want it to mean.
That water is transparent to visible light is an objective scientific fact.
That the atmosphere is not transparent to visible light is an object scientific fact.
The physics of this are very well known, in traditional science. Whatever else is happening must be related to the tried and tested basics.
Good link, thanks.
I’ll put a comparison up for discussion on my site.
I ran this last year:
http://tallbloke.wordpress.com/2010/06/21/willie-soon-brings-sunshine-to-the-debate-on-solar-climate-link/
My question is a simple one. If the DLR is so much greater than solar radiation, then why are the poles so much colder than the equator? The small difference in total radiation (solar + DLR) between summer and winter should mean that we don’t experience any large difference in temperature between winter and summer.
Especially Antarctica? The DLR should heat the Antarctic substantially during the winter, when their is no sunshine, preventing the extreme cold we see at the poles. During summer, since the angle of incidence is low, the solar radiation should have almost no effect. Antarctica should be about the same temperature summer and winter.
Since we don’t see this, this would appear to be direct, first order evidence that DLR is not significantly heating the planet. If it was, if DLR was so much greater than solar radiation, then the Antarctic in winter should be about the same temperature as the Antarctic in summer. Europe in the winter should be about the same temperature as Europe in the summer.
ferd berple says:
August 30, 2011 at 7:29 am
“The DLR should heat the Antarctic substantially during the winter, when their is no sunshine, preventing the extreme cold …”
Outer space is 3 K. With no sunshine and only outward radiation, the surface should cool toward 3 K (-270 C). I would say the radiation from the atmosphere is QUITE effective at preventing the extreme cold (-270 C), keeping it at a much “balmier” ~ -55 C during the winter at the South Pole (http://en.wikipedia.org/wiki/South_Pole#Climate.2C_and_day_and_night). During the summer, the sunlight can push this all the way up to ~ -25 C (Yes, there are other effects at play, but “DLR” is certainly one significant factor limiting the cooling at the poles during the winter.)
Tim Folkerts says:
August 30, 2011 at 9:52 am
Outer space is 3 K. With no sunshine and only outward radiation, the surface should cool toward 3 K (-270 C). I would say the radiation from the atmosphere is QUITE effective at preventing the extreme cold (-270 C), keeping it at a much “balmier” ~ -55 C during the winter at the South Pole
Tim, please. Convective transport from the equator is what supports the temperatures at the poles, not radiation, of which there is comparitively little.
Myrrh says:
August 30, 2011 at 4:15 am
It’s pretty well meaningless when water is transparent to visible and doesn’t absorb it.
Empirically determined coefficients of absorption are strong evidence that water does indeed absorb visible light. Better evidence than anything you’ve come up with to say it doesn’t.
That the atmosphere is not transparent to visible light is an object scientific fact.
Yeah? How come I can see for 50 miles or more from a mountain top on a clear day, and yet it’s completely dark a lot less than a mile under the surface of the sea?
??
jae says:
August 29, 2011 at 6:38 pm
Now you have really done it, confusing people with observed facts, that is not how science is done, you must have equations and models. Sarc off
Tim Folkerts,
“This seems like a complete mis-interpretation of “backradiation” to me. ”
The Slayers mostly address the mythology that has built up in place of the science. The IPCC types can scream about this approach all they want. If they had communicated the science better initially there wouldn’t be all those poorly understood myths out there!! Of course, if they had tried to explain the REAL science they wouldn’t have gotten anywhere in the first place!! They apparently made the decision to allow the myths to propagate in place of the science and are now paying for that decision by losing support.
You can call it knocking down strawmen, but, when the majority of the population believes those strawmen…
JAE says:
“My favorite example is a comparison of the temperature between Phoenix and Atlanta (same latitude and elevation) in August. Phoenix is MUCH hotter, despite the fact that Atlanta has 3 times as much “greenhouse gases.” WHY? So let’s chalk that up to energy lost by evaporation of water. ”
I’m confused. You seem to be saying that your favorite comparison is not really a good example because there is another factor (evaporation) that should be important, making the comparison ineffective to begin with? (Not to mention differences in cloud cover and vegetation.)
And please provide evidence of your other assertion about greenhouses. Do you have data on similar greenhouses showing that the one in Atlanta is indeed cooler on a day with similar sunshine?
In fact, this map pretty well explains both assertions: http://www.azsolarcenter.org/images/articles/az/solmap.gif
AZ gets much more sunshine, that GA, which would be the primary factor in the higher average temperatures of both the cities and the greenhouses. Do note that Phoenix cools down significantly more at night than Atlanta. Hmmm — now there indeed is an observed effect of the extra GHGs (water vapor) around Atlantla, providing DLR to limit the cooling of Atlanta overnight.
Tim F says:
“AZ gets much more sunshine, than GA, which would be the primary factor in the higher average temperatures of both the cities and the greenhouses.”
So it’s clouds that regulate the temperature? That makes way more sense than “carbon”.
Green Sand,
“The UK – Annual – “Mean Temperature” and the “Sunshine Hours” appear to correlate very closely, sort of makes sense, more sunshine = warming, less = cooling? Admittedly a gross over simplification, but it is actual observational data.”
You didn’t use the terms forcing or feedback or unprecedented. Couldn’t have anything to do with Climate Science!! 8>)
Smokey asks: “So it’s clouds that regulate the temperature? ”
Of course clouds regulate temperature. Clouds are one of the key factors. But you are way too well-informed to feign ignorance that there are MANY factors that influence climate – changes in the sun, changes in the earth’s orbit, changes in clouds. And, yes, changes in “DLR” also influence the climate.
David A says:
August 30, 2011 at 4:10 am
Tim Folkerts, do you have a comment on this??
Tim Folkerts @ur momisugly August 29, 2011 at 10:51 pm
I think you may still be missing my point. The S-B calculation gives the total radiant energy distributed hemispherically from the surface. (per Stefan’s experiment with a small flat body pointing into a hemispherical body). It is apparent that your 390W/m^2 contains both horizontal and vertical vectors. In other words, the horizontal vectors are part of the 390, but by definition, they do not go up. Thus the vertical (normal) vector integration should be less than 390.
I agree that it seems incredible that Trenberth and others could have made a mistake, such as in thinking that S-B gives the normal radiation rather than hemispherical, but some strange things have happened in climate science. It could be something silly like thinking that “total” means the total of all (Planck distribution) wavelengths in the normal, but if that is not the case, there is clearly a paradox that you seem unable to address.
Tim Folkerts says:
“I’m confused. You seem to be saying that your favorite comparison is not really a good example because there is another factor (evaporation) that should be important, making the comparison ineffective to begin with? (Not to mention differences in cloud cover and vegetation.)”
Look here for my data: http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/sum2/state.html
Look at maximums (clear days in Atlanta and Phoenix). Phoenix does have less solar radiation (10 kwh/m2/day than Phoenix (12 kwh/m2/day), but Atlanta has over three times as much GHGs, so the direct solar radiation should be MORE than made up by the backradiation from all those GHGs, eh?
You got me on data from actual greenhouses, but I’ll bet you a six-pack that I’m correct.
But you also note:
“Do note that Phoenix cools down significantly more at night than Atlanta. Hmmm — now there indeed is an observed effect of the extra GHGs (water vapor) around Atlantla, providing DLR to limit the cooling of Atlanta overnight”.”
Do note from the data source I provide that you are completely wrong. You suffer from the “cold desert night myth.”
Your turn.
Tim:
More on the possible source of your “confusion:”
IF the GHE content of the atmosphere is a significant “actor” in our climate, then WHY OH WHY aren’t the areas with maximum GHEs (tropics) warmer than they are? Where is that “amplification” provided by water vapor? Why are the tropics not getting warmer, with additional OCO? IF clouds and evaporation do, indeed, “compensate” for additional GHEs, then the additional GHEs don’t have any real influence, right?
SO, even if the radiation cartoons make any sense, the postulated radiative exchanges don’t affect the temperature/climate. Maybe THAT is why the empirical evidence doesn’t match the hype?
Willis’ “thermostatic control systems” theories probably explain very well what is going on (Mother Earth has a governor on heat content), regardless of the effects of the GHGs.
Bob_FJ says: “It is apparent that your 390W/m^2 contains both horizontal and vertical vectors. In other words, the horizontal vectors are part of the 390, but by definition, they do not go up. ”
No — I would say every photon emitted has heads off in some direction that contains both a horizontal and vertical component. And in fact, the horizontal component cannot be exactly zero, since then it would not leave the ground. So, a purely horizontal vector is NOT part of the 390 W/m^2. Every photon leaving the ground has at least SOME vertical component. Every photon will eventually leave thru any arbitrary sphere I draw around the earth.
OK — one last new explanation I just thought of.
Suppose 390 W of IR energy leaves a 1m x 1m square of the ground. I build a 100 m tall square hollow column of perfect mirrors that channels the light upward. This will reflect the 390 W worth of photons so that all the IR energy passes thru the 1m x 1m square at the top of the column. Now I build a whole grid of these all over the world. Every 1m x 1m square that is 100 m above the ground will have a flux of 390 W.
Now the fun part. I remove all of the mirrors. The energy from my first square will now spread out and pass thru thousands of other upper squares. But conversely, light from thousands of other lower squares will spread out and pass thru the original upper square. The mirrors didn’t create or destroy any energy. We must still have 390 W passing thru any upper square. And the 100 m was arbitrary; the same would be true at any height.
JAE:
“Do note from the data source I provide that you are completely wrong. You suffer from the “cold desert night myth.””
Well, “from the data you provided”, Atlanta has an average change from day to night of 11.1 C, while Phoenix has a change of 14.8 C. So apparently you are completely wrong about me being completely wrong.
Look at maximums (clear days in Atlanta and Phoenix). Phoenix does have less solar radiation (10 kwh/m2/day than Phoenix (12 kwh/m2/day)
First, you need to use “flat plat, 0 degree tilt” data. Your numbers inflate the true isolation.
Looking specifically at July, Pho gets a max of 7.1 kWh/m^2 (~ 300 W/m^2 average over 24 hr) and Atl gets 5.7 kHh/m^2 (~ 240 W/m^2). That is an extra ~ 60 W/m^2 averaged over 24 hr, or more than 100 W/m^2 extra during the daylight hours during the best day of July. The average difference is a little less, but comparable. That is a considerable bonus for Pho.
the direct solar radiation should be MORE than made up by the back radiation from all those GHGs, eh?
I would not necessarily assume that. How much difference do you think the difference in conditions from Alt to Pho will make on the DLR? Will it be more than 60 W/m^2 to make the temperatures similar in the two locations? Oh, and it has to make up for the difference in evaporative cooling edge Atlanta has, too.
Tim Folkerts @ur momisugly August 30, 2011 at 7:21 pm
No Tim, the horizontal components ARE part of the 390, but they go “sideways”, not up, and as you have severally agreed, (E.G. on August 29, 2011 at 10:51 pm The energy flying around within a region (eg horizontally) may be interesting in some ways, but is not part of the TRANSFER between regions) This followed your lecture on radiative HEAT transfer. In fact, in any typical elemental homogenous layer in the atmosphere, from simple logic/observation, there is no HEAT transfer because T is uniform because there is no potential difference in the EMR level, despite that the lateral emissions are far more intense than in the vertical. Note that in the horizontal plane that this occurs, whilst directions of radiation vary through 360 degrees, somehow those naughty photons and molecules sort it all out with net zero HEAT transfer. You raise an objection that the initial surface emission in itself may not be perfectly horizontal, but this is not an issue. The initial surface emission is not the end of the story, because it drives the secondary spherical absorption/emissions, and the surface emissions are balanced by those in the elemental layers above
When you said; Every photon will eventually leave thru any arbitrary sphere I draw around the earth I wonder if that is what you meant to say, and why. Only a minority of photons are emitted from the surface out to space, most are absorbed and cease to exist, to be replaced by others, not necessarily of the same value or molecule source, quite close to the surface. And of course there are collisions and a lot of other stuff going on.
I thought your additional thought exercise was a bit fanciful, and my concluding points above would seem to be pertinent in part.