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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“Why is the huge 400 percent INCREASE (of three million+) in submarine volcanic and thermal vent activity LEFT OUT OF THEIR EQUATION???It surely would be greater than a miniscule amount of AWG.”
Al the estimates I have seen put geothermal energy flux at ~ 0.1 W/m^2. Even if the energy flow did increase by 400 % to 0.4 W/m, this is still a pretty small affect. A forcing of 0.3 W/m^s would be significant, but hardly “huge”.
And that all assumes that there was a true increase, not just an increase in the known activity. If there had been 0.4 W/m^2 all along, then just discovering new volcanoes would not CHANGE the climate.
just a word of support for mr springer.
meritocracy is wonderful; pecking order is not tolerable.
i’m probably not the only one who can distinguish the difference.
i really am fed up with the aroma of domination growing here. willis is now like romm and mosher like gavin. stuff the drama and go back to mama.
i liked it when Anthony ran the place and held to standards which distinguished wuwt from most other sites that quickly become vulgar from ego trippers running down other guests- a clique in quest of a claque. i’m not off topic, either. they make themselves the topic every chance they get.
forum clingers are always a problem that way. they don’t do any of the work to create the venue or get it to become a going concern, they just camp on it and try to take it over and sacrifice it to their flaming vanities.
gnomish,
So you support ad hominem attacks. Got it.
Willis says “Dave, you still haven’t explained how the ocean can lose 400 w/m2 in radiation, gain 170 w/m2 from the sun, and still stay liquid.”
How about inflated measurements of DLR and OLR using supposed gross energy transfers when only the net flow should be used:
http://claesjohnson.blogspot.com/2011/08/how-to-fool-world-by-measuring-masive.html
http://claesjohnson.blogspot.com/2011/08/how-to-fool-yourself-with-pyrgeometer.html
Myrrh,
“The ‘missing heat’ is Thermal Infrared direct from the Sun…”
In case no one else has answered, that was one of my issues until I found the data. The earth and sun radiation levels cross in the 4-5 micron range. The near IR from 4 microns down is actually included in the visible absorbed numbers I believe. That is where the sun substantially exceeds the earth. From 5 up it is very small and absorbed in the atmosphere. Of course, if they don’t… I still haven’t had anyone explicitly state what the IPCC uses. Probably will have to read the one section to find out for sure. I don’t really believe they are trying to ignore almost 50% of the sun’s output. That is just a bit more than the DLR.
wobble says:
August 16, 2011 at 7:08 pm
Nope, not possible, not unless you have an explanation for what keeps the ocean liquid. We know the ocean is losing 400 w/m2 of energy through radiation. We know it’s only getting about 170 w/m2 from the sun … what makes up the difference?
I say DLR, there’s no other energy source around to do it. So no, it’s not possible that the warming is negligible.
w.
Dave Springer says: August 16, 2011 at 6:15 pm
This 114 W/m2 is the amount of energy that doesn’t leave the surface radiatively. Compare this to 48 W/m2 which is the amount of energy that does leave the surface radiatively. LWIR emission only accounts for 48/114 or 42% of all radiative heat loss from the surface, land and ocean combined. For the ocean-only the radiative loss is only 25% (see my previous link to ocean heat budget).
Actually (using your numbers), LWIR accounts for 100% of all radiative heat loss, but 48/162 = 29% of total heat loss.
What this means is that the lion’s share of heat loss is not via radiation and that’s especially true over the ocean. Where radiative loss is not a large factor neither can greenhouse gases be a large factor because radiation is only mechanism by which GHGs do their GHG thing.
Let me give an analogy as to why I disagree with your conclusion. Suppose i have a large balloon. It is leaking ~ 390 l/min thru a square hole, 80 l/min thru a round hole, and 30 l/min thru a triangular hole. That is a net loss of 500 l/min. But there is a second square hole with a blower that adds 320 l/min to the balloon. And there is a rectangular hole with a blower adding another 180 l/min. With all of this, the balloon is neither inflating nor deflating.
It would be silly to say that the 390 l/min leaking thru the square hole is not very important because there is a different square hole that is simultaneous adding most of this added air back. You would say BOTH holes are important. A 10% change in the square hole leak would be much more important than a 10% change in any of the other leaks.
We can split hairs and discuss if the “sizes of the holes” are quite right, but there is no way to avoid the fact that the huge “square holes” (ie upward & downward IR energy fluxes) are important.
To push the analogy a bit farther than I probably should, we could ask what would happen if we turned the blower up from 390 l/min to 400 l/m. The pressure would increase, causing more air to leak from all three holes. the increase would not necessarily have to increase proportionately for the three leaks, but they would all leak more. And more importantly, the pressure would be raise inside the balloon until the new equilibrium is reached.
For the climate, the analogous argument is obviously that an increase in DLR would increase the surface temperature, causing increases in evaporation, convection and IR radiation. Evaporation will only increase if the surface temperature increases (barring changes to winds, etc), which will by necessity also increase radiation and convection.
Willis, just to remind you I know the DLR plays a role in keeping the oceans warm…but you’re article and understanding at the time of writing were off. I’ll refute your arguments since you keep pleading for someone to do so.
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.”
No its not. DLR is NOT absorbed in the first mm of water, its absorbed in the first 10um of the water and the remaining 99990um of that first mm *increase* in temperature with depth. The place where the DLR is absorbed is the coldest place. Conduction cannot happen.
Compare this to land where the top of the earth is the warmest place and conduction can happily warm the earth below.
Argument 2 “If the DLR isn’t heating the water, where is it going?”
As described earlier, it is largely immediately radiated back up. Up and down for basically zero net effect. Except some is lost to space and some to evaporation and the shortfalls are made up from energy from the bulk of the ocean moved to the surface by convection and conduction, supplied in the first place by the sun.
So does this mean DLR heats the ocean? Yes, but not directly. It is the sun that heated the ocean. The DLR ONLY slows that energy from escaping.
Argument 3 “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”
This is closest you had to correct. However your statement “But in addition to the wind-driven turbulence of the topmost layer mixing the DLR energy downwards into lower layers” betrays the fact you believed the topmost layer to be heated by DLR and warmer than the bulk. The fact is that if the topmost layer were to mix downward, then for the next few mm or so, it would be *cooling* the ocean, not warming it…and its only from 1mm down where the ocean is warmer than below where mixing down warms the ocean below. The important point here is that this warmer water 1mm down wasn’t directly warmed by the DLR. DLR played a role in it being as warm as it is, but not in the sense you meant.
Argument 4 “Without the heating from the DLR, there’s not enough heating to explain the current liquid state of the ocean.”
Is also close to being correct in the sense that DLR plays a role in keeping the ocean warm. Its the specifics that matter here though. Why? Because you’re trying to describe them in your article.
In response to those who say that when the skin layer is warmed by EMR the heat won’t propagate downwards, heating a liquid from the top stratifies it. In this situation, the thermal conductivity “k” comes into play. For water, it’s about six-tenths of a watt per square metre per degree C. The relevant formula is
q = k A ∆T / L
where A is the area, ∆T is temperature difference over the distance L.
This means that if the top surface of the ocean is hotter by one degree than it is a metre down, six-tenths of a watt/m2 is moving downwards by thermal conduction. A 5 degree difference from the surface to one metre down, conductance of 0.6 times 5 metres gives us three watts per square metre warming the water a metre down. That’s significant in my book, doubling CO2 is suppose to be 4 watts/m2 or so.
In this regard, water is no different than any other substance, it has a characteristic thermal conductivity, which is the rate at which heat passes through that substance. Ice, curiously, is a much better conductor of heat than is liquid water, which leads to counterintuitive results in the polar regions.
Of course, this is during the day. During the night, convection takes the lead away from thermal conduction as the dominant heat transfer mechanism. This is because the ocean is overturning at night. All night long water is rising to the surface, cooling through radiation and evaporation, moving laterally across the surface and sinking in scattered columns to the depths again. See Figure 5 here. The night-time DLR delays the onset of the overturning, and slows it once it is established. This leaves the bulk of the upper ocean warmer than if there were no DLR.
If there were no DLR absorbed by the ocean, the ocean surface would be losing massive amounts of heat, and would soon cool to a new much colder equilibrium.
w.
The oceans stay liquid because atmospheric pressure dictates the energy value of the latent heat of evaporation and that sets the rate at which energy can be lost to the air via evaporation by setting the energy cost of the evaporative process.
If atmospheric pressure were reduced to zero the energy cost of the latent heat of evaporation would be so small that not only would the oceans retain no solar energy at all but they would instantly vaporise just as happens to water released to space.
If atmospheric pressure were to be increased then the energy cost of the evaporative process would rise and the oceans would retain more solar energy than they do now for a higher equilibrium temperature.
We all know that water boils at a lower temperature at the top of Everest than at the sea surface.
It is the energy cost of evaporation at a given atmospheric pressure that controls the equilibrium temperature of the ocean bulk and thus the equilibrium temperature of the entire Earth system. In the process it keeps the oceans in a liquid state at current atmospheric pressure.
DLR only affects the rate at which energy is transferred from molecules in the interacting layer in the very top few microns of the sea surface to space via the atmosphere. It does not cool or warm the ocean bulk since it cannot affect the rate at which energy is released by the oceans. That rate is affected only by the energy cost of the evaporative process which is pressure dependent combined with the quantity of solar shortwave input at being retained any given moment.
So more solar input or a rise in atmospheric pressure raises the equilibrium temperature.
Less solar input or a fall in atmospheric pressure reduces the equilibrium temperature.
Differing combinations of such changes alter the equilibrium temperature up or down depending on the relative proportions of changes in those two parameters.
Full explanation here:
http://www.irishweatheronline.com/news/environment/wilde-weather/setting-and-maintaining-of-earth%e2%80%99s-equilibrium-temperature/18931.html
Dave Springer says:
August 15, 2011 at 7:57 pm
Keith Minto says:
August 15, 2011 at 7:01 pm
“If the air at the ocean surface is humid that means it has already condensed and released its heat;”
Wrong. You can see it if it condenses. If it condenses near the surface we call it fog. If it condenses farther up we call it clouds. In either case you can see it after it condenses. If you can’t see it then it hasn’t condensed.
++++++++++++
Actually you can only see it if it is larger than 0.1 microns (which reflects visible light). Lots of condensed water vapour is invisible. The droplest form on cloud condensation nuclei (CCN) and are extremely small for some time. Clouds induced in this manner by galactic cosmic rays are particularly small and last longer in the sub-optical state bceause they are slightly charged and avoid each other. This can mislead (a lot) people using visibile light to measure cloud cover by satellite.
Thanks for your many comments above (until you started to get snippy). It was informative and covered many important aspects of the topic.
Willis, I agree with your main argument that the presence of anything above the ocean that impedes direct radiation of LWR to space will slow the cooling, which some are mis-interpreting as ‘warming’. Yes, it may be warmer, but it was not ‘additionally warmed’. This is an extremely important point which all should concede.
There is no doubt that the core of AGW is that the cooling rate will be reduced by additional CO2, and that the interference with the status quo ante will be catastrophic. Obviously the argument is simplistic bceause if any (of many) additional heat loss mechanisms is enhanced or triggered, the heat loss will be pretty much the same or even more. This appears to be the case as natural variation overwhelms significant increases in CO2. End of short story.
“In response to those who say that when the skin layer is warmed by EMR the heat won’t propagate downwards, heating a liquid from the top stratifies it.”
Specifics Willis. You’re ignoring them. This isn’t a “macro” effect, its one that takes place at the very surface of the ocean. Stratification is certainly an effect and an important one…but not one that is relevent to this discussion.
http://en.wikipedia.org/wiki/File:MODIS_and_AIRS_SST_comp_fig2.i.jpg
I believe many people get led astray when they hear infra-red radiation described as ‘heat radiation.’ This band of electromagnetic energy is the primary heat-transfer radiation band only for objects that are less than red hot. The sun is white hot. Just look at an energy (heat) spectrum of sunlight. The peak energy is around 0.5 microns (500 nm.) The primary CO2 absorption band is at 15 microns, a much longer wavelength.
Sometimes visible light is characterized as ‘cool’ because we are very sensitive to low intensity light levels. “Average indoor lighting ranges from 100 to 1,000 lux, and average outdoor sunlight is about 50,000 lux.”
Interesting question,
Guess there is a connection to higher altitude and thus lower air temperature, lower relative relative humidity and the fact that rivers start high and inland. The more or less linear flow plus channel resistance, would result in ‘churning’ turbulence and warm surface/cold bottom water overturning. Just a thought, and it can be tested.
Wow, too much discussion! Can we go back to basics with maybe a permanent reference page (Anthony have you considered a ‘pillars of climate science’ primer?) – this stuff is pretty critical. How about an energy balance diagram (probably with citations) to show what we “know” (from actual measurements) and what we theorise (from the gaps). It MUST have been done before.
I can see it wouldn’t be trivial though, EMR is quantised so you’d need all the relevant absorption spectra. You’d need to integrate absorption through the atmosphere and then into the ocean. Then of course you need incoming and outgoing radiation and consequent conduction. Add, aerosols, precipitation, latitude, currents, evaporation, wind, sea-spray, clouds and sediment/algal loading and you’d be pretty complex (and not steady state!) in the real world. But some simple lab experiments would be interesting.
Willis
You are right. To be accurate, DLR means that the surface is warmer than if the DLR weren’t there. So you are technically correct, but in common parlance we don’t usually say “It slows the cooling so it ends up warmer than it would otherwise”. We just say “it warms it”.
But this statement completely contradicts your initial post
The sun heats the surface. At best DLR slightly slows the rate of cooling. To say it warms the surface is incorrect.
DLR can not heat the ocean or the land
I was going to ask a ton of questions, but I read through the comments and figured its not worth it in the end. Enough people were being rather feisty that I thought it might be better to just read and learn. I did not really understand the article completely (as in what was the reasoning for these 4 points….?) until I read the back-story, so those of you still posting might want to go back and read that, it helped me understand the reasoning going on here.
Another thing, I think this article was a little lower quality for only that reason. The explanations made me curious enough to read more, so don’t feel bad about this. Just remember that some of us are unaware of previous discussion on the subject and are coming into this subject with just the background information. It helps a ton if we have the counter-points to work with too up front. Why do people dispute this? I think that angle might have helped as well too.
Personally, I have not formed an opinion yet, its late, its time for bed and I want to read through the material one more time. Physics late at night is asking for nightmares!
———————————-
“Dumb question
How does rivers figure in all this?Rivers are always cold are they not?Is that because of their depth ? ”
——————————————-
What river are you talking about? I live in Missouri obviously and I can tell you some rivers are rather warm and tend to match the air temperature to a large extent, while others stay around the same temperature year round…the physics is not really relevant with rivers as they flow quicky enough and are a small enough body that their temperature is mostly depended on the source of the water. The physics is more important in the ocean interaction since that is such a large portion of our Earth, and although rivers react very similar to the oceans (larger rivers that is) the effect is so miniscule that its not even worth noting inside of an energy budget. You are better off just calculating the oceans and estimating the difference between fresh and salt water then anything else.
The factors in the temperature of rivers include snow melt *percentage of river’s source, spring fed or not, and how much of the river is spring fed and where is the source – distance and time taken make a huge difference in River Temperature, and of course ambient temperature. That is quite a mouthful, but its a rather small part of the energy budget being discussed. Its rather not important for the Earth’s climate as a whole. But for individual eco-systems, the river systems can make quite a difference.
Willis
“Nope, not possible, not unless you have an explanation for what keeps the ocean liquid. We know the ocean is losing 400 w/m2 of energy through radiation. We know it’s only getting about 170 w/m2 from the sun … what makes up the difference?”
Maybe your figures are just warmist fiction. LWR radiation does not heat the planet. Its time to move on from this nonsense.
Willis Eschenbach says:
August 16, 2011 at 8:05 pm
We know the ocean is losing 400 w/m2 of energy through radiation. We know it’s only getting about 170 w/m2 from the sun … what makes up the difference?
DLR makes up the difference Willis.
>I say DLR, there’s no other energy source around to do it. So no, it’s not possible that the warming is negligible.
This is known as non-sequiteur. The second part doesn’t logically follow from the first. DLR is absorbed in the first few nm of the ocean surface. Because a large number of Watts of energy get concentrated into such a thin layer, significant evaporation takes place. Evaporation is a process which soaks up energy and leaves the surface of the body it has evaporated from cooler rather than warmer.
Absorbing energy doesn’t necessarily result in things getting warmer. Especially if the thing is a body of water. Rocks are different of course.
In the case of the DLR being absorbed in the ocean surface, we have numbers coming out of Trenberth’s models, and numbers coming out of NASA’s real empirical measurements which show convective processes including evaporation to be more significant than they are in the Trenberth model, as Dave Springer has elucidated.
Normally, I’d expect Willis to go with real numbers derived from real empirical tests. In this case however, he prefers the numbers coming out of Trenberth’s model.
Very strange.
Tinthetoolman
So does this mean DLR heats the ocean? Yes, but not directly. It is the sun that heated the ocean. The DLR ONLY slows that energy from escaping.
Not yes. the correct answer is no. LWR does NOT heat either the land or ocean. It may reduce the rate of cooling by a fraction.
The sun and only the sun heats the surface
“Argument 4 “Without the heating from the DLR, there’s not enough heating to explain the current liquid state of the ocean.”
Is also close to being correct in the sense ”
It is not correct. You say the heating is caused by the sun. So if this is correct (and it is) then this statement can not be correct
Willis Eschenbach @ur momisugly August 16, 2011 at 6:49 pm
Willis, the problem is that although you may not have mentioned the word HEAT, you have seemingly generally been treating EMR as if it were HEAT, whereas they are actually two different forms of energy with clearly defined different behaviours. Maybe the confusion arises from them both generally being measured in the same units, (they need not be), and from a good few climate scientists apparently not understanding (or “denying“?) the differences.
When you speak of warming, presumably you mean that the temperature of the affected matter has increased as a consequence of heating. Temperature of matter can only be increased by the (non quantum transient) addition of HEAT. (and of course vice versa for cooling). Whilst it is true that EMR can be converted to HEAT, EMR itself cannot be added to matter. What can happen is that certain molecules in matter can be excited by absorption of the photon stream duality in EMR at some wavelengths. When this happens, EMR is converted to HEAT. (it is no longer EMR). There is also other quantum stuff, such as molecular collisions, and other forms of HEAT transfer, but let’s keep it simple.
ALL types of energy transfer require a Potential Difference, including simple stuff like hydraulic energy, where H1 – H2 gives a PD as the difference in height of the liquid, H2 being the gravitationally lower.
In the case of radiative heat transfer, the PD is generally considered as the difference in power of two opposing sources, OR as proportional to T1^4 – T2^4. (in a naive two-body case)
As I pointed out earlier, it doesn’t matter how much EMR is flying around; unless there is a PD, there is ZERO HEAT transfer. This is nicely demonstrated in any elemental layer of air in a discreet parcel, wherein most of the radiation as a consequence of its temperature is horizontally opposed in all directions. Consequence = nothing.
The 400 W/m^2 that you imply as HEAT leaving the surface, is NOT HEAT, but a different form of energy described as EMR, which does not in itself cool the surface.
Do you have any problems with this NASA Energy Budget Diagram?
http://science-edu.larc.nasa.gov/EDDOCS/images/Erb/components2.gif
TimTheToolMan says:
August 16, 2011 at 8:29 pm
I haven’t changed my understanding since then.
Oh, please, I’m not “pleading” for anything, I don’t do pleading, that’s called “projection” on your part. You make it sound like you’re doing me a favor, rather than trying to establish your own claims.
I didn’t want to get into an argument about whether it is absorbed in 10 or 50 micrometres, so I just said it is absorbed in the first millimetre, which avoids the discussion and also happens to be true.
OK, so at least we can see what we agree on. We agree that the DLR is getting absorbed by the ocean. Now, when DLR is absorbed in water, however many micro-metres that takes, what form is that energy converted to?
It is converted to thermal energy. So we are getting somewhere. You agree, for starters, that DLR a) is absorbed by the ocean, and that b) when it hits it is converted to thermal energy, leaving the ocean warmer than it would be otherwise. We also agree that the surface is slightly cooler in the top mm.
What I don’t understand why “conduction cannot happen”. Conduction is always happening, both down and upwards in the water column depending on local temperatures. Convection is also always happening.
As you point out, the actual skin surface of the ocean is almost always slightly cooler than the water immediately below. This is because the surface is cooled by evaporation, conduction to the atmosphere, and radiation.
As a result, the skin almost always runs a bit cooler than the water underneath it, with the predictable result—the very surface skin water is always radiating, cooling and sinking a mm or so, then warming from the warm waters below, and rising again. The very surface is constantly being replaced by slightly warmer water from underneath in a very thin skin-based circulation layer. In this way the heat of the ocean makes it to the surface to be evaporated away.
With this constant interchange, with water surfacing, radiating, sinking a mm or so, warming, and rising again to the skin of the ocean, the DLR striking the surface has the same effect it has at night. It slows the thermal circulation, this time the thin vertical circulation at the very surface. Again it slows the motion of the bulk heat to the surface to cool. As a result, the bulk ocean is warmer than it would be without the DLR.
During the day, sunlight striking the ocean is absorbed most at the surface. If the DLR is warming the skin itself, that absorbed solar energy can’t be moved as easily to the skin and radiated/evaporated away. This warms the layer directly below the skin. So again, despite the fact that it is absorbed at the surface it affects the lower layers and the bulk itself.
I don’t see that. Between the day and the night the top of the earth varies between warmer and colder than the land below it. So at dawn, despite what you would describe as the “top of the earth being the coldest place” the sun still warms the earth surface and thence the earth below.
I would agree except for the “immediately”, it suggests that it is re-radiated. It is not re-radiated in any sense. It is absorbed. By and large it is turned into heat, although it may turn into the physical energy needed to dislodge a water molecule from the surface.
After the radiation is turned into thermal energy in the ocean, it is radiated back up, indistinguishable from any other thermal radiation from the ocean. That’s what happens when radiation hits the ocean. And I think we’ve already agreed that the radiation hitting the ocean mostly turns into thermal energy. Yes, some of it goes into evaporation, as you go on to point out:
You’re making my argument. You agree that the DLR is absorbed by the ocean, that it turns into thermal energy and is added to the thermal radiation (w/m2), or goes into evaporation.
Yes, I agree, and I see that as just naming. The ocean is much warmer than it would be if there were no DLR. You can call it what you want, warming, or slowing the cooling, I don’t understand the difference. All I know is that the bulk of the upper ocean with the DLR is warmer than it would be without DLR. I call that DLR warming the bulk of the ocean, but YMMV.
First, you are correct. I simplified the situation. Normally, the actual skin itself and down a millimetre or so is slightly cooler than the water below it.
I said that the DLR slows the night-time overturning, and leaves the bulk of the ocean warmer than it would otherwise be … how was that wrong? My intention was to refute the argument that DLR can’t affect the bulk temperature of the ocean. I think I did so.
Interesting. We get to the end, and you agree that without DLR there’s not enough warming to explain the liquid state of the ocean. Your issue is that I haven’t described the specifics of how that works in enough detail, I haven’t talked about the funny little “hook” in the temperature versus depth chart at the last millimetre with the actual skin slightly cooler than below. Guilty as charged, I didn’t discuss it.
I keep returning to the question of known losses from the ocean. These are ~ 390 w/m2 radiation, ~ 80 w/m2 evaporation, ~ 20 w/m2 sensible heat, total ~ 490 w/m2.
Sun hitting the ocean surface is about 170 w/m2. Since the ocean is basically in balance, that means it’s getting about 320 w/m2 from somewhere.
I say that 320 w/m2 comes from DLR. Most of the loss is in the form of thermal radiation, meaning that the DLR has hit the ocean and been converted to thermal energy.
You can call that “warming” or “slowing the cooling”. Either way, most of the DLR has hit the ocean and been converted to thermal energy. And no matter what name you give it, the ocean is much warmer with DLR than it would be without it. The choice of names for that situation is yours.
Thank you for taking the time to actually address my questions, Tim, much appreciated.
w.
Perhaps we can just consider this in simple terms – it suits my simple mind!
During the day sunlight warms the sea, which has an enormous capability to store this heat via the specific heat of water and its mass. At night the heating from the sun stops. At this point, the sea will be radiating energy at a rate controlled by its surface temperature and also losing some heat by convection and evaportion. Immediately above its surface is an atmosphere whose vapour content (ie vapour pressure) depends on the temperature of the sea surface and which will be radiating energy towards the sea at a rate determined by its temperature(DLR) and also losing energy by radiation and conduction upwards.
There is no source of heat to provide additional energy, so that the sea will be losing energy at a rate determined by the properties of this atmosphere and will cool. However the sea has a vast store of energy held at a temperature determined by its mass and its specific heat. The cooler water will sink and be replaced by the slightly lower sub-surface temperature in the process, (overturning). In this respect, the DLR from the atmosphere close to the sea surface returns some of the radiated energy and slows the rate of heat loss and thus the rate of sea-surface temperature loss.
Next morning, the sun driven heating starts all over again. The same processes of DLR, evaporation,conduction and convection occur, but in this case the downward HF from the sun dominates theheating process.
This process allows the sea to lose energy at a rate determined by its surface temperature but to maintain a relatively high bulk temperature. It is essentially a “flywheel effect” My slight acquaintance with shallow lakes, where the mass of water is small relative to its surface area suggests that the “flywheel” is much smaller also, i.e. they cool relatively rapidly at night.
In essence the near surface atmosphere is acting to provide the same observable effect as an insulating blanket performs on an initially hot, non heat generating body, after the source of heat has been removed eg a hot water bottle placed in a bed, although the principle method of heat loss from the bottle is by conduction.
If the above explanation is acceptable, it demonstrates, yet again, the remarkable combination of physical properties of H2O, to which we mortals owe a rather large debt of gratitude!
kuhnkat says:
August 16, 2011 at 8:02 pm
Myrrh,
“The ‘missing heat’ is Thermal Infrared direct from the Sun…”
In case no one else has answered, that was one of my issues until I found the data. The earth and sun radiation levels cross in the 4-5 micron range. The near IR from 4 microns down is actually included in the visible absorbed numbers I believe. That is where the sun substantially exceeds the earth. From 5 up it is very small and absorbed in the atmosphere. Of course, if they don’t… I still haven’t had anyone explicitly state what the IPCC uses. Probably will have to read the one section to find out for sure. I don’t really believe they are trying to ignore almost 50% of the sun’s output. That is just a bit more than the DLR.
You should have stuck with it being an issue – the data you found is obviously from the AGWScience ficition propaganda department.
Bob_FJ says:
August 16, 2011 at 6:27 pm
Myrrh @ur momisugly August 16, 2011 at 5:02 pm
“…Downwelling Solar 170 W/m^2 is not heating the Earth. Visible Light, UV and Nr IR are not thermal energies – they cannot be heating the land and oceans to raise the temperature by the amount claimed nor can they therefore create that much Infrared upwelling from the Earth…”
Sorry Myrrh, but the term “thermal radiation” is sometimes confused and misused. It is really a misnomer for EMR, (electromagnetic radiation) which includes visible light which does indeed heat matter when its photons are absorbed. Try here at Wikipedia:
http://en.wikipedia.org/wiki/Thermal_radiation
Do you know how much thermal infrared is given off by the incandescent bulb it gives as an example in the second parargraph? 95%
The 5% visible light doesn’t heat anything.
The first paragraph is what is screwing with your heads in this. “All matter with a temperature greater than absolute zero emits thermal radiation.”
I don’t put my dinner in the fridge to cook. Near infrared is not thermal radiation.
I don’t know how much clearer I can make this – I’ve given the tradition physics and given a page where NASA used to teach this, to children, that the heat we feel from the Sun is thermal infrared and that near infrared isn’t hot at all, it’s not a thermal energy. This is basic primary school level physics. And, I’ve given a page where they are spouting another variation from the AGWScience fiction propaganda department that infrared doesn’t even reach the Earth!
Visible light and and the two shortwave energies either side of UV and Nr Infrared are not thermal energies, that means they do not heat things, that means they can’t heat land and oceans. That means the ‘energy’ imput from the Sun from these wavelengths has nothing to do with heating the Earth, they have to be taken out of your calculations.
That’s why everything being argued about here is unadulterated gobbledegook! You don’t know how insane you all sound saying Light heats the Earth. You’ve been brainwashed.
The italics should stop end of para 4:
http://wattsupwiththat.com/2011/08/15/radiating-the-ocean/#comment-720340
I’ve put the comparison out again in http://wattsupwiththat.com/2011/08/15/radiating-the-ocean/#comment-720489
There are countless real world applications in use created out of the knowing there is a difference between Light energies and Heat energies. As the NASA page for children used to teach, thermal infrared is used in cooking food. You can’t cook food by shining Blue Visible Light on it!
From the real world example:
And, I’ve given the history of that page from NASA she quotes – at the moment someone has managed to keep it up as a live link. There’s a fight going on over there..
All of you posting here who claim that the Solar of Visible and the two non-thermal either side heat the land and oceans NEED to prove it. This is a science blog. I am getting fed up with asking for proof and being ignored.
If you just continue discussing this as if my post doesn’t matter then you’re just a bunch of dreamers arguing about the fictional worlds you’re creating here. You’re not scientists in any bloody shape or form.
I repeat:
Visible light and and the two shortwave energies either side of UV and Nr Infrared are not thermal energies, that means they do not heat things, that means they can’t heat land and oceans. That means the ‘energy’ imput from the Sun from these wavelengths has nothing to do with heating the Earth, they have to be taken out of your calculations.
If you just continue discussing this as if my post doesn’t matter then you’re just a bunch of dreamers arguing about the fictional worlds you’re creating here. You’re not scientists in any bloody shape or form.
Tim Folkerts @ur momisugly August 16, 2011 at 7:09 pm
Well as I indicated, I don’t like doing analogies because none can be perfect. I’m not comfortable with your “better analogy”. Please explain more what you mean by a ‘net current’ from two separated electrical circuits.