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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Brian W says:
August 15, 2011 at 10:02 pm
“Neither clouds, nor water, fellows DO NOT glow in IR. Since IR is by definition non visible radiation, YOU CANNOT SEE IT.”
Yeah, but some animals can. I hope you aren’t some kind of species bigot who thinks human eyeballs are some kind of universal standard for what glows and what doesn’t?
http://en.wikipedia.org/wiki/Infrared_sensing_in_snakes
Various people above have claimed that DLR is real because you measure it with a radiometer AND it increases when relative humidity increases. Well folks, you really do need a basic course in engineering heat transfer starting with Prevost’s Law then Hoyt C Hottell’s 1954 paper on calculating the emissivity and absorptivity of gases, then moving onto Kirchhoff’s radiation Law, a corollary of the 2nd Law of Thermodynamics.
Prevost’s Law of Exchanges [1840] states that at radiative equilibrium, any body above absolute zero emits radiation and receives exactly the same radiation from the opposite direction. In the case of hot gases, it’s spherical emission and absorption. If there’s an excess in a particular direction, there is no equilibrium. So when you point a radiometer upwards to measure ‘DLR’, you then have to reverse it to measure ‘ULR’ and the difference is what causes heating or cooling.
Hottell showed how you calculate emissivity as a function of pressure and concentration. Increase the concentration of a greenhouse gas and you increase emissivity. So DLR only apparently increases; in reality, the radiative flux in the opposite direction also has to increase.
This is why clouds appear warmer; emissivity tends to unity compared with c. 0.1 for moist air at ambient pressure. This leads onto Kirchhoff’s Law which is that at radiative equilibrium, emissivity = absorptivity.
I find it amazing that any physical scientist should not know these basic scientific facts. Go away until you do know them because this DLR fantasy has to stop.
@Willis
“Please stop the condescending snarkiness, it just makes you look ugly.”
Then please stop parroting Trenberth, it just makes you look stupid.
The fact is Willis that you’re rightly a stickler for precision. Precision in thinking leads to precision in analysis and thinking the DLR warms the ocean is sloppy and going to lead you astray.
Ooh look clouds overhead, the DLR has increased by 100W/m2, thats got to really be heating the ocean now!
DSR warms the ocean. DLR slows the rate of cooling.
ferd berple says:
August 15, 2011 at 9:44 pm
Because a) DLR is lower at the poles, and b) the ULR plus evaporation is higher than the DLR plus solar input, otherwise the block of ice would be melting, wouldn’t it? … now how about the answer to my question?
w.
Hey Willis,
If I sell you a beat up surfboard for $390 and give you an instant rebate of $340 what’s your actual cost for the surfboard?
You and Trenberth sure have some interesting methods of accounting. Maybe you should both be in congress. You’d fit right in. You could collect $390 billion in carbon taxes, refund $340 billion of it in carbon credits, then add to your stump speech that you increased government revenue by $390 billion.
I’m sorry for mocking this but some things just plain deserve mockery.
steven mosher says:
August 15, 2011 at 4:07 pm
I sit outside on a freezing winter night with a space blanket.
The blanket doesnt warm me. The blanket slows the heat loss via radiation.
Actually Mosh, the silvering on the space blanket does very very little. A piece of clear plastic will be very nearly as effective. This is because nearly all of the effectiveness of a space blanket is in reducing convection, and thus, wind-chill. The radiative component is tiny by comparison. Tests have been done on this in the climbing and backpacking magazines years ago. Maybe you can find the info online too.
Smokey says:
August 15, 2011 at 5:36 pm
As we all know, heat is transferred by conduction, convection and radiation. If the top 50 micrometers of the ocean is warmed by IR, wouldn’t those molecules slough off their extra energy almost instantly via conduction, warming the adjacent molecules? And so on, transferring the heat deeper into the ocean. Am I missing something?
Yes, you’re missing the fact that warmed water molecules become more buoyant than their neighbors and head upwards. Rock particles don’t do that.
Smokey says:
August 15, 2011 at 7:37 pm
And of course, something is warming the oceans.
Yep, it’s called the Sun.
Willis,
you want serious? OK, dead serious, here is the problem with individual energy flows.
IF there was no atmosphere and no GHG’s above the ocean the instant temperature and energy emissions would have no relation to 390 w/m2. Computing this number is an abortion. My understanding of this from people who understand how to derive the equation is that it simply is not real.
The fact that there IS atmosphere and GHG’s above the ocean means that there has been a relative equilibrium reached where you CAN measure these fluxes, BUT, they are not meaningful without the opposing flux. Saying there is 390 w/m2 is only meaningful if there is ALSO 320 w/m2 down to go back up to create that much energy in the first place. The IR down is the IR up, time shifted by a tiny amount of time, minus the losses that went on out and were transferred to the atmosphere and a few other miscellaneous things. Talking about heating the ocean is poor semantics as the flux is into the ocean with the SW and out of the ocean with IR. IF you wanted to get really picky we would have to include the gravitational energy and electrical energy that disrupts the ocean and atmosphere adding to the wind from the convection. Just like the conduction between dissimilar objects, at a very low level there may be occasional flows against the gradient, but, generally it is all warmer to cooler. I would stick with the SLOWS COOLING and forget the abortion of 390 w/m2 as it only allows people to get confused. If you say 390 you must say 320… (or whatever the correct numbers of the situation are)
“I can hand you a hundred dollar bill, and at the same time you hand me four twenties. That’s one way to describe the transaction, the way I described it above, listing the individual flows. ”
You could also give me a hundred dollar bill without me giving you back anything. The ocean cannot give the atmosphere 390 w/m2 without first getting the 320!!!! At least not with our current set up.
I apologise for misquoting you. Your statment was: “It can’t be heating the air, because the atmosphere has far too little thermal mass.” But some of it is heating the air.
The best idea is to ignore the manner in which Climate Scientists talk about it dividing the fluxes that cannot exist without each other and speak about the net flow. This may make no one happy, but, is most realistic. The surface regime emits about 60 w/m2. The instant fluxes making up this amount are ~390 up and ~320 down. The ocean absorbs plenty of SW to create this balance.
PS: I was addicted to cocaine twice so, if you want to make fun of me for it I deserve it!!! As an absolute and not just because of this. Reading your bio didn’t give me the feeling you had been an addict so I apologize if this was a low blow.
Dave Springer says:
August 15, 2011 at 10:18 pm
Stop acting like I’m an idiot and like Trenberth is making stupid assumptions, Dave, it’s a foolish error in both cases. We know what we’re talking about. Here’s the part that you seem not to understand:
You (and the cited paper) are talking about net radiation flows. Trenberth and I are talking about individual radiation flows.
For some reason you (and Kuhnkat) seem to think that the net flow method is the only valid method. In fact, the description of individual flows actually describes the physical processes. There actually are two separate and distinct radiation flows, one in each direction. Your “net flow” description is the one that has no direct equivalent in the real world, it is a mathematical construct. It’s a real and valid construct, a useful construct to be sure but the individual flow method is just as real and valid, and it also has the huge advantage of being an accurate description of the actual underlying reality.
w.
tallbloke says:
August 15, 2011 at 11:36 pm
That would only be true if the upper water molecules could warm the lower molecules to a higher temperature than the upper molecules … but they can’t do that, heat won’t flow uphill.
So the lower molecules, although warmed by the upper molecules, will be cooler than the upper molecules. As a result, despite the fact that they are warming, they won’t “head upwards” as you claim. I discussed this above.
w.
Tallbloke,
I would add the space blanket also retains the moisture which carries the most energy!! My first experience with a space blanket was one that belonged to a friend. I had a cheap bedroll and we were sleeping on the ground outside a Yosemite campground to save a few bucks. There was a drizzle so my friend loaned me his space blanket. I ended up wetter than if I hadn’t used it!!! All my body moisture condensed in the cheap bedroll soaking me. Of course I didn’t get that cold until I got out of it in the morning in wet clothes. DANG!!!
Tallbloke,
That reminds me of a Greenhouse test with IR treated and NON-IR treated plastic covers of the same material and thickness to prove IR effectiveness. The actual numbers were close to 5 degrees difference between the IR treated cover and the non-IR cover. I was shocked. I then reread the specs and found the IR treated cover ALSO had a treatment to minimize condensation collecting on it. The reduced moisture condensing on the cover made most of the difference I believe!! None of the other Greenhouse covers treated for IR were that effective with the same thickness and type material!!
Eschenbach-sensai.
Moderation leads to generosity,
Mercy leads to courage,
Humility leads to leadership.
Please do not take offense with the deriding tones of various “unpleasantries”. As mentioned before, there are issues with working with the discrete and jumping back to the bulk. I see things discussed here very similar to the counter-intuitive concepts of gravity that Galileo discovered with the balls on a ramp. To some, they may be be clear, but to others, the details cloud the picture.
The two concepts that Mosher-sensai mention are not inconceivable, but the discrete level does cause issues. Unless the atmospheric energy transfer model can be conveyed to why the anticyclonic (Red Spot, and the additional coalition of white spots) event on Jupiter has persisted for possibly hundreds of years, there will be questions.
Thank you for contribution to at least my knowledge.
POST SCRIPT (TO ALL THAT ARE DEBATING DLR):
This issue is NOT the the NET Daytime Radiation. The ISSUE is the NIGHTTIME BLANKET EFFECT. When the SUN is out, it will ALWAYS dominate the “energy budget”. Obviously it is the FIREPLACE that warms our world. When the IR saturated H2O, CO2 and other vibrational molecules fall back to sea level at night, some are not ABSORBING new energy. Nighttime tempertures will be “slightly warmer”, which will allow the oceans to retain more heat from the DLR. Vector algebra still works, only in the dark ;).
I believe a successful model of Jupiter would be a huge step in modelling, that is if there are no solids to screw up the equations 😉
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.
There are lots of good arguments against the AGW consensus, but this one is just silly.
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 …
The craziest, ugliest, silliest, nonsensical impossible thing (you set the tone, Willis, not me) is that an ocean which receives a net input of 200Wm can emit more than that and sustain the loss indefinitely. Conservation of energy is a bitch that isn’t going to budge.
This is ground control to Major Tom.
Your circuit’s dead, there’s something wrong
Can you hear me, Major Tom?
Can you hear me, Major Tom?
Can you hear me, Major Tom?
Can you….
@Willis
“Stop acting like I’m an idiot and like Trenberth is making stupid assumptions, Dave, it’s a foolish error in both cases. We know what we’re talking about. Here’s the part that you seem not to understand:
You (and the cited paper) are talking about net radiation flows. Trenberth and I are talking about individual radiation flows.”
Glad to oblige. Stop acting like an idiot and I’ll treating you like one. The net flow is all that matters. Get that through your thick skull.
@tallbloke
“The question is, do DLR heated water molecules make it downwards far enough for long enough to warm the ocean bulk. I think the answer is no, because warmer water molecules are naturally buoyant”
Again we are in the realm of semantics, but the energy flow is clear. Since the slowly overturning ocean is warmer than it would be in the absence of nighttime DLR, we say DLR warms the bulk ocean. How? By preventing the bulk ocean from cooling.
I don’t know if Willis is going to respond to my comment directly, so for now I’ll have to pick through the thread to see where he has answered other people by addressing my arguments.
The energy flow is indeed clear. The net effect of long wave radiation at the ocean-air interface is to cool the ocean by some 66W/m^2. Talking about downward flow of long wave radiation without considering upward (and sideways!) flow at the same time doesn’t make sense to me. It’s a flux.
.The bulk ocean is actually warmer because of the DLR … but not because the “DLR heated water molecules make it downwards” as Tallbloke suggests
Willis has this the wrong way round. He said in argument one:
“the ocean can circulate the heat downwards through turbulence”
and I said:
“.do DLR heated water molecules make it downwards far enough for long enough to warm the ocean bulk. I think the answer is no, because warmer water molecules are naturally buoyant, and because the vortices which mix solar energy so efficiently are below the wave troughs, several thousands of times deeper down than the depth DLR penetrates water to.”
But anyway, I’m glad Willis has abandoned argument one.
Willis Eschenbach says:
August 15, 2011 at 10:14 pm
The claim seems to be (e.g. Tallbloke)
Warm water molecules rise to the top. Warm rock molecules conduct heat to their neighbours, which can’t go anywhere.
IR heats the top molecule. It passes some reduced amount of that heat to the molecule below. But what tallbloke forgets is that the top molecule can’t make the second molecule warmer than the top molecule, heat doesn’t flow from cooler to warmer.
Radiative transfer is a quantum operation according to theory, a water molecule can’t pass part of a photon. If a water molecule emits a photon to it’s neighbor below and drops to a lower vibrational state it becomes ‘cooler’ that the molecule below, which will rise to displace it. It’s worth noting at this point that the ocean surface is nearly always warmer than the air above it, and cooler than the water below it, so conduction isn’t going to work to get energy downwards either, as the second law of thermodynamics has to be observed. Any conduction taking place will be from the ocean into the air, because as Willis correctly states:
“heat doesn’t flow from cooler to warmer.”
I haven’t had time to read all the comments. so if I’ve missed another of WIllis’ references to my comment then I hope someone will flag it up. I’d be particularly interested to know if he has addressed my concluding point:
“But this isn’t about absolutes. I’m sure the increased DLR warmed the ocean a little bit, or at least slowed its rate of cooling a little bit. I think the increased insolation due to (empirically measured) reduced cloud cover in the tropics 1980-1998 did a lot more to increase ocean heat content. To turn your question back to you, where else could that energy have gone?”
For those who insist that DLR reduces the cooling and does not warm the surface consider the following analogy. Consider two groups of people are facing each other. A machine throws huge rocks over the heads of group A towards group B. Some of the rocks richochet and are lost the rest break into pieces. The people from group B pick up the pieces and throw them back. Some of these pieces fly past group A but others are picked up by group A who throw them back to group B. Now we know that all the rocks originally came from the machine but how do we describe the bombardment of group B? Do we say that they are bombarded by big and small rocks? Or do we say that they are bombarded by big rocks and the presence of group A reduces the number of small rocks that group B throws? I do not think the latter describes reality. One can say that the presence of group A reduces the rate at which small rocks are lost from around the feet of group B but this is not analogeous to warming or reduced cooling it is analogeous to heat accumulation. To recognise the difference one only has to consider the melting of ice which involves heat accumulation but no warming. It would be like group B collecting rocks in piles and waiting before throwing them back.
Another bottom line. Trenberth (and Willis by association) are the ones who can’t find the missing heat from the last 50 years. I told y’all where it is. It’s distributed more or less uniformally in a spherical volume of space 100 light years in diameter surrounding the earth.
Keep spinning your wheels looking downward into the deep ocean if you must. I can lead a horse to water but I can’t make him drink. All I really ask is that you don’t reach into my wallet to cover the cost of your wild goose chase, K?
This here is a oiece from a paper by NIWA.
Decadal temperature changes in the Tasman Sea(There was a warming of the Tasman Sea deep to 800 mtre.)
Quote
“The first possible forcing mechanism to consideris air-sea flux. This mechanism is unlikely given the depth penetration of the warming signal, as surfacewarming would increase stratification rather than warm the deep ocean. Air-sea flux can also be eliminated as a possibility by examining European Centre for Medium-range Weather Forecasts(ECMWF) and National Centers for Environmental Prediction (NCEP) heat flux data. The ECMWF andNCEP products indicate that the annually-smoothedheat flux varies between c. 10 W/m2 and c. 40 W/m2 with a mean of c. 25 W/m2. However, the heatflux is always from the ocean to the atmosphere, i.e.,the ocean is losing heat to the atmosphere rather than gaining it”.
publications-journals-nzjm-2005-107-lo.pdf (261.68K)
publications-journals-nzjm-2005-107-lo.pdf
This link works
http://www.royalsociety.org.nz/media/publications-journals-nzjm-2005-107-lo.pdf
“Since the second molecule is not as warm as the top molecule, in contradiction to tallbloke’s claim, it doesn’t rise to the top. And the same for the layers further down. The heat is transmitted down and down, but each layer can’t heat the lower layer more than itself, heat won’t flow uphill. So the water, though warming, doesn’t “rise to the top” as claimed.”
Nice thought but you’re ignoring the fact that the ocean is radiating upwards more than the atmosphere radiates towards it. The energy flow is upwards not downwards. Therefore the molecules at the top are on average losing more energy than they are gaining and so there is no downwards movement of heat as you suggest.
Its my view that the energy the DLR imparts on the topmost ocean surface molecules is very quickly re-radiated back up, so you can think of radiation at the surface of the ocean as bouncing between the atmosphere (CO2 and water vapour) and the water itself. Minus that which is used for evaporation. This is a simplistic explanation so dont bother attacking it on lack of detail. A more detailed explanation was made over at the Science of Doom.
Hmm Tallbloke. Rather than trust a magazine about how reflective insulation works or does not work I think I trust the stuff I built for DOD. And I’ll use my thermos to keep my coffee from cooling faster than it would. And If I have to go near a wacking hot fire i’ll also wear a reflective suit
here have some fun. there’s plenty more
http://www.insul.net/howto.php
And yes, if you use a space blanket too long you get hoarfrost in the inside.. cause its working. but eventually get to the fire
testing testing the comments under obesity and AGW are not working
You note that nobody (except willis) wants to look at the empirical evidence. I posted it up there boys..
Perhaps the D word should be allowed for this topic