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.
Bob_FJ,
1) Myrrh is quite sure of his position and has been for months. Trying to convince him otherwise is futile.
2) I understand your point, but I am not confused about the difference between “heat” and “energy” and “EMR”. I was specifically talking energy flows. Upward IR does indeed carry more energy than evaporation. Downward IR carries quite a bit of energy, too, but in the opposite direction.
Heat is the net flow of energy due to temperature differences. By this definition, there is no reason to only lump the two IR energy flows together, as you are suggesting. ALL the energy transfers due to temperatures differences should be lumped together to calculate the heat. THE heat to the surface would then be + 168 + 324 – 390 – 24 – 78 = 0 (using the old Trenberth numbers).
We could group these in a variety of ways. Your suggestion of grouping by type has much merit — ie combining the +324 – 390 = -66 (presumably the “15% listed above). This highlights types of energy flows.
We could also group them by direction of flow: 492 in and 492 out. This highlights the net balance.
We could subdivide the -390 by where it is going: -350 to the atmosphere and – 40 to space.
My point is that there are many legitimate ways to look at the energy flows. There are many legitimate subsets to look at. Different subsets are interesting and useful in different situations.
PS — I just noticed that the wording in the diagram and your own post use “EMR” and “heat” inconsistently. The third line should be “NET radiation absorbed by atmosphere”. The atmosphere DOES absorb ~ 350 W/m^2 of EMR from the ground, which is a little over 100% of the sun’s rate. The atmosphere does indeed emit large amounts of EMR. It is only the NET EMR (which we could call “EMR heat between ground and atmosphere”) that is ~ 15%.
“Distilled water is transparent to visible light and has a remarkable diamond like clarity, even compared to tap water.”
The transparency of water depends on the thickness of the sample – the thicker it is the more light is absorbed. Obviously.
Here
http://en.wikipedia.org/wiki/File:Water_absorption_spectrum.png
is a graph of absorbency versus frequency for pure liquid water. Note that the frequency is given as a log scale. Note the dimensions of the y-axis. The amount of light transmitted falls off exponentially. Thus if the absorption coefficient 1 and the sample is 1 cm thick then the intensity will be reduced by a factor of 1/e where e=2.78 i.e it is reduced to about 36% of its starting intensity. If you look at the values then the absorption coefficient is ~100 in the infra-red. So here it takes a few millimetres to absorb the light. In the visible the coefficient is ~1/1000 to ~1/10000 so it takes a few metres to absorb the light. But the important point is – the coefficient is NEVER zero, and with sufficient depth ALL the light is absorbed, which means ALL the energy is absorbed, and since it is not re-emitted as visible light, ALL that energy is retained as heat (at least until it is emitted as LWIR from the surface)
Now could people please stop talking nonsense and claiming that visible light is not absorbed by water.
Keith Minto says:
August 17, 2011 at 9:19 pm (Edit)
Responding to an earlier comment:
….
Visible light is only PARTIALLY transmitted through water, a fact which is obvious if you ask why is is completely dark below a certain depth.
Distilled water is transparent to visible light and has a remarkable diamond like clarity, even compared to tap water.
OK. You’ve ID’ed part of the problem being discussed.
The IR is absorbed high – at the very top of the (perfectly calm) water column of 100 meters. Up there, the IR-induced heat increases evaporation, and causes a (partial) loss of the heat energy being shined downed from the sun.
A little lower, the visible light penetrates, and some up it turns into plant energy (by the planton and smaller veggies up there) which gets by larger things which get eaten by larger things and …… and eventually they decay on the bottom of the ocean.
The remainder of the visible light turns into ??? (Heat obviously). The wind-swept currents and upper-surface turmoil mix up that mythical first few microns that do absorb the IR and store that IR heat (top 10 cm’s of water ) 1-3 meters down.
It is this moderate-depth absorbed light energy and the real-world mixing of real-world ocean waves and wind that is not (often) discussed above.
My earnest question to Mr. Mosher (or other knowledge persona’s) is what are the latitude by longitude actual heat radiation values “assumed” by the CGM’s to be received at each longitude and latitude on the earth.
If they (the CAGW propagandists who wish to control the world’s life) begin with nothing more accurate than a average world-wide year-wide basis of 100 km x 100 km squares from the equator to the poles, then they are attempting to re-create the pyramids by assuming grains of sand were found randomly spread across the desert. And then proving that the grains of sand cannot move uphill to form the pyramids.
Myrhh,
Your own quote says “” ….a recirculating water jacket that absorbs and removes non-photosynthetic energy”. Seriously, do you have any idea what energy is and how it is converted between radiation, kinetic energy, heat energy, that it is conserved…???
You might also consider that, although the exterior of a spacecraft has no temperature it is also the biggest vacuum thermos possible?? Handling heat has to be an important issue in the design. You don’t radiate extra heat into your environment that has to be removed by the expenditure of more energy. The plants only need certain wavelengths for photosynthesis. Why give them the whole spectrum?? Why use WATER to remove that radiation if it can’t absorb it???
http://www.botany.uwc.ac.za/ecotree/photosynthesis/spectrum.htm
Shows that the Infrared band is not used by photosynthesis. Guess what you are screaming about as the heat band?? Guess what water absorbs really well?? Not that it doesn’t absorb visible light, just not much or it couldn’t penetrate to 100 meters depth. In other words, most of the infrared will be absorbed by that thin layer of water while very little of the desired visible bands will be absorbed. That water is heated so can be circulated past a transparent window or near the surface of the craft to RADIATE away that heat if they don’t use it elsewhere!!
The reason you FEEL infrared is that it excites the molecules of h2o in your skin similar to a microwave!!! It actually carries less energy but more of it is absorbed!!
Oh, and if you don’t think water absorbs visible light, you need to remember that all those plants and debris in water does. Why it gets really black in the deep oceans. Notice in this spectra that water absorption is LOW in the visible, but, it DOES absorb.
http://en.wikipedia.org/wiki/File:Water_absorption_spectrum.png
Tim Folkerts @ur momisugly August 17, 2011 at 9:46 pm
Yes Tim, I’ve now come to that same conclusion too, although I didn’t know that he/she has been making such gobsmacking assertions for months. If Myrrh cannot accept that sunlight fades to nothing from around 100m in seawater and what that means, or the principle of conservation of energy, then he would seem to be beyond salvation.
It reminds me of some Christadelphians I encountered in Adelaide (Oz) that were unmovedly convinced that the Grand Canyon was created just a few thousand years ago in the great Biblical flood, and that dinosaurs like T-Rex existed alongside humans, despite that they are not mentioned in the Bible whereas the frequently mentioned king of beasts; the lion, is. Similar stuff I saw on TV docos, like an interview with a Grand Canyon helicopter tour guide, saying it‘s all in the Bible.
Actually, I prefer an hypothesis that was put to me that the Grand Canyon was created when a Scotsman dropped a penny in the area and then futilely attempted to recover it.
Your other points; and thanks for your interest; I’ll respond to separately, possibly in a combined comment to Willis.
IR Heat Radiation Fallacy
As objects become warmer, their peak radiation wavelength becomes ever shorter. We can use the peak radiation energy to measure temperature. Just like the infrared band, light is electromagnetic energy. The equations are the same. As the wavelengths get shorter, we do not get into a new area of behavior until the individual photons become so energetic that they can rip molecules apart. A monochromatic optical laser beam is hot. You can get a nasty burn if you focus an image of the sun on your hand with a large magnifying glass. [Hint: never leave such a glass in a position where it may accidently focus sunlight on paper]
The only reason that you might think of light being cool with respect to infrared is that indoor lighting levels are usually not more than 2 percent of the intensity of natural sunlight. If a stove got white hot, you would not want to be anywhere near; it would be blinding hot–literally.
Yes, infrared light carries heat. Optical light does as well and requires fewer photons for the same amount of heat.
http://en.wikipedia.org/wiki/Black_body
Visible light is only PARTIALLY transmitted through water, a fact which is obvious if you ask why is is completely dark below a certain depth
Because energy from the Sun isn’t eternal. Because matter slows down light. Water is matter, the deeper you go the greater the pressure. When you switch off your table lamp, where does the light go?
Get real with your scales, none of you could measure your way out of a paper bag.
You don’t take into consideration the difference in properties. What’s the difference in size between the near infrared and longwave infrared? See the NASA page for children. Short wave works on the scale of electrons. Tiny. Gets bashed about even by the electrons of the molecules of nitrogen and oxygen in the atmosphere – that’s what reflection and scattering is. That’s why we have a blue sky. It’s weak compared with thermal infrared which works on a molecular scale, actually moving molecules to higher energy states, which is what temperature is. But in water, the molecules don’t even let the visible in to their dance. They can’t move the molecules to higher energy states. They do not convert water to heat. They are transmitted through unchanged.
It takes the more powerful heat energy of thermal infrared to move molecules of water to heat. Water is a great absorber of thermal infrared. That’s why the water cooled light to leave only visible which is not hot and which the plants use for photosynthesis which is a chemical change in the use of visible light energy – it does not create heat. It creates sugars which then create heat when they are burned for energy.
Don’t come back with more nitpicking gibberish here. Your energy budget says Visible light raises the temperature of land and oceans to heat. If you can’t appreciate how utterly stupid that concept is, it’s not my fault. You haven’t been paying attention.
Water is transparent to visible light, it is not absorbed, it is transmitted through unchanged. It does not heat water. You have to take the AGWScience fiction claim that you’ve all been brainwashed into believing out of your energy budget. Your arguments are nonsense.
This includes the nonsense that longwave thermal infrared direct from the Sun does not heat the oceans. Either because you’re saying that longwave infrared doesn’t reach the surface of the earth and only back-radiated thermal is in play, or as above, you think visible light is thermal, capable of heating water, and thermal infrared isn’t absorbed by the oceans. You’re in a complete muddle.
Water is a great absorber of thermal infrared, longwave. That’s how your bodies get warmed up internally from the Sun, you’re mostly water. UV light doesn’t make it past the first layer of the epidermis, visible light can penetrate fractionally deeper, then it gets reflected out, that’s why you cast shadows. The shorter near infrared is shorter and so more reflective like visible light, but it penetrates deeper still before being reflected out. That’s how near infrared cameras work in the dark and in getting through clouds to see what is behind them in cosmic photography. This is a different process to thermal imaging which measures the heat radiated from a body. You don’t understand differences in processes because you have zilch understanding of differences in properties. That AGWScience fiction mantra that all electromagnetic energy is the same and all energy creates heat has trapped you in a one dimensional world without scale or volume. You won’t understand what I’ve just written until you step out of it and into the real world this side of the mirror. Until you do, you’re stuck in an impossible world with Alice where you argue among yourselves about your fictional concepts of matter without properties and where you adjust physical laws to suit your make-believe worlds. Water has a great capacity to store heat, it takes longer to warm up and it takes longer to cool down. That’s what’s happening in our oceans. In the real world.
Do not think about the following until you have understood the above.
Good bye.
Well Myrrh,
since I am so stupid or deluded you still need to explain why the bottom of the oceans are black.
Oh Myrrh,
While you are straightening me out, how does UV stopped by the skin damage DNA?
Where does all that solar-far infrared that heats us come from at night??
Why don’t plants use far-infrared to drive photosynthesis which is energy intensive?
How does far-infrared absorbed by the surface of the water heat at depth with no reverse convection?
How does that weak visible light when magnified by a magnifying glass burn paper? (oh, sorry, that’s far-infrared isn’t it)
Are you really saying that science has been corrupted as far back as Stefan-Boltzman, Gustav Kirchoff and all the rest of those old guys who gave us those neat equations to compute stuff?
Myrrh, I gotta admit, you do live in a magical world.
jimmi_the_dalek says:
August 17, 2011 at 4:52 pm
Looking at all this, I am puzzled by something. There is a lot of discussion of cooling of the ocean surface by evaporation, but where is the opposite vector included? ie. where is condensation? All that evaporated water must eventually condense, exactly reversing the latent heat transfer, fall as rain, and eventually must get back into the ocean – not necessarily the same part of the ocean, but that does not matter. So when people quote a figure of X watts/sq m for the cooling effect, is that net of the condensation? or just the flow in one direction?
Hi Jimmi,
The ‘opposite vector’ would exist if the raindrops were warmer than the ocean by the time they hit it.
In general, they’re not.
Rainfall further cools the ocean.
The Sun warms the ocean, the ocean warms the air, the air loses energy to space. In the middle of this process, the air radiates some energy gained from the ocean back down to the ocean, plus some energy gained directly from the Sun. These are very much second order effects. Heat rises.
Tim Folkerts,
I knew you would have to get around to it. Most of the energy came from the ground which came from the sun.
Got another question for you Myrrh, (do you know Frankencense?)
Since heat generates light why does it generate infrared when it is cooler, but can’t generate visible, UV, and shorter wavelengths until it gets a LOT hotter??
Myrrh,
I just remembered another gentleman who occasionally posts needs your help. Y’see, he uses a heat gun to try and heat this bucket of water. Seems no matter how long he holds that gun above the surface of the water the bucket just doesn’t warm up. He wants to know why it doesn’t warm up but his pool does in the sun, yeah, he could fry an egg on that heat gun, but, it would be messy.
richard verney says:
August 17, 2011 at 10:56 am
I have pointed out a number of times how radiation on the top skin layer of the ocean can affect the bulk temperature of the ocean, regardless of the temperature of the skin surface. It does so by slowing the cooling of the ocean, which increases the temperature of the bulk ocean. It also does so without the need for the DLR to heat the whole.
If you have trouble with that concept, consider a room in a cold climate with a stove in it and an open door. Your claim is equivalent to saying “the door only changes the situation at the very outer edge of the room, so closing it can’t affect the bulk temperature of the room.”
But anything that affects the heat loss of a system changes the bulk temperature of the entire system. DLR absorbed within the upper mm of the ocean slows the heat loss from the ocean. As a result, the bulk temperature of the upper layer of the ocean increases throughout, it all becomes warmer than it would have been in the absence of the DLR.
Until you grasp that nettle, I fear that you won’t understand how DLR does affect all of the upper ocean even though it only penetrates less than a millimetre.
w.
Here’s a little info that might move the discussion forward.
The thermal conductivity of water is ~ 0.6 W / m*K
The top of the ocean is about 0.2 K cooler than it is 1 mm down.
This leads to a flow of about 0.6 W/m*K * 0.2 K / 0.001m = 120 W/m^2 by conduction from the “deeper layer” 1 mm down up to the surface.
Note that this is highly uncertain, since the 1 mm and 0.2 K are fairly rough estimates. If the surface was indeed 0.3 K cooler, the value jumps to ~170 W/m^2. Different wind or humidity would play a big role. Also, since the top is cooler, this would lead to some convection in the top mm, increasing the flow of energy. Bottom line — the energy flow up from the ocean thru the surface could easily be pretty much anywhere in the range of roughly 50 – 300 W/m^2.
Note also that this includes the “typical” solar energy into the surface of 170 W/m^2. This is good because it provides a mechanism to remove the solar energy from the ocean so that it is not continually warming. In fact, you could easily argue that the magnitude of this temperature gradient is “self-tuned” so that the upward thermal energy flux roughly matches the average downward solar energy flux, regulating the temperature of the ocean.
And here is an interesting conjecture. Suppose that DLR increases. This would deposit more energy in skin layer of the ocean, raising the temperature slightly. One effect would be to increase the evaporation rate (warm water evaporates faster), which would moderate the amount the surface temperature increases. A second effect would be to decrease the thermal gradient and hence decrease the thermal conduction up from the lower parts of the ocean. And of course, anything that limits the flow of energy from the ocean will necessarily increase the temperature of the ocean.
The logical conclusion from this conjecture — the more DLR, the warmer the oceans will get.
Links for my previous comment:
The thermal conductivity of water is ~ 0.6 W / m*K
[http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html]
The top of the ocean is about 0.2 K cooler than it is 1 mm down.
[http://ghrsst-pp.metoffice.com/pages/sst_definitions/]
tallbloke says:
August 17, 2011 at 11:54 am
Tallbloke, that’s a lovely theory. Evaporated water molecules form an “invisible mist” above the surface. I’ve never heard of an “invisible mist” above the surface of the ocean … so surely you have some photos or some observations of this “invisible mist”, or at least a claim that someone has actually detected or measured the “invisible mist” …
Perhaps that works with your friends, Roger, that you wave your hands and say that the dance of the photons is what keeps DLR from warming the ocean, and that the photons are dancing because of an invisible mist above the water … around here we need a bit more than that.
If something is warmer because “X” is happening, we say that “X” is warming the something. You claim that X isn’t warming anything at all … but if so, why is the something warmer?
I don’t see “distinct processes” being conflated. In my example, “X” is sending mysterious rays to an object. When those rays strike the object, it is converted to thermal energy, and the object ends up warmer than it would be if it had not absorbed the mystery rays. We call the rays “thermal radiation”.
What is the second “distinct process” that the DLR is doing that I’m conflating with DLR hitting something and warming it?
That’s because you refuse to see that when something “slows down the cooling of the ocean”, the bulk of the ocean ends up warmer. We call that “warming the ocean”, and yes, it occurs simply by slowing the cooling.
You’re looking at this backwards. In a system in which the surface is maintained at a slightly lower temperature than the bulk … what happens if you forcibly warm the surface? Think it through all the way, Roger. The very surface warms … until it’s slightly warmer than the bulk … which then heats up slightly, until the surface is slightly cooler than the bulk, and the previous condition (cooler surface) is restored.
Unless your claim is that such a system can’t be heated from the top … but I don’t think that’s your claim.
Have you ever seen the ocean? There’s turbulence there that will pull down a swimmer, much less fingernail sized pieces of paper. Wind plus ocean equals turbulence that sinks ships, so I haven’t a clue what your claim means, or what designing pumps has to do with it.
TB, because the ocean can only lose energy through the top, the top is always slightly cooler than the layer below.
What seems to have escaped you is that this setup, cooler water on top of warmer water, is inherently unstable because the cooler water is denser than the warmer, and it wants to sink, and does so. The cooler surface is kept in existence by water moving to the surface, cooling, sinking a mm or so, rewarming, rising to the surface, cooling, sinking a mm or so, and so on.
So rather than being thermally isolated from the bulk below as you seem to be claiming, the cooler skin surface is constantly exchanging energy and water molecules with the bulk ocean below. And of course, because of that, any radiation absorbed by the skin surface affects the heat loss (and perforce the temperature) of the bulk of the upper ocean.
In other words, the DLR doesn’t need to penetrate to the depths in order to warm the depths.
w.
O H Dahlsveen says:
August 17, 2011 at 11:56 am
If you think the issue is whether CO2 adds heat to the system, you’re definitely in the wrong discussion. CO2 doesn’t add and can’t add heat to the system.
What it can do is slow the rate at which the system cools. This leaves the system warmer than if there were no CO2.
Despite the system being warmer than it would be without CO2, some people object to calling it “warming”. I don’t know why, since the physical end result is identical no matter what we call it—the system is warmer than it otherwise would be.
w.
Willis said:
“The very surface warms … until it’s slightly warmer than the bulk … which then heats up slightly, until the surface is slightly cooler than the bulk, and the previous condition (cooler surface) is restored.”
I’m not aware of the ocean skin (as opposed to the interacting zone at the very surface) EVER getting warmer than the bulk globally on average. Locally and temporarily maybe but never globally or long term.
A few surface molecules in the interacting zone warm up but then evaporate earlier than they otherwise would have done which uses up any DLR left over after increased evaporation, convection and radiation from the individual molecules have taken their respective slices.
There are 3 layers not two. The molecules in the interactive zone that do warm up until they evaporate. The ocean skin itself up to 1mm deep which appears NOT to warm up and the ocean bulk which shows no sign of warming up either.
The only logical conclusion is that events in the interacting zone are bufferred from the ocean bulk by the cooler ocean skin.
Still waiting to hear why a IR-transparent greenhouse isn’t any hotter in Atlanta than in Phoenix (same elevation and latitude) on a hot summer day, given that there should be WAY more backradiation in Atlanta (from all the water vapor).
Further to my previous post we need actual evidence that more DLR actually DECREASES the thermal gradient across the interface between the ocean skin and the ocean bulk below.
I have found no evidence that it actually does so on a global basis. The 1mm deep cooler layer seems to be global and permanent.
I am aware of some efforts being made to design experiments and/or sensors that would resolve the issue but we are not there yet.
The cooling power of evaporation is such that it seems unlikely to me that the thermal gradient would decrease.
In fact one would think that in view of the power of evaporative cooling more DLR should actually deepen that cooler layer and INCREASE the gradient. However I don’t think it can because once the DLR has been used up the process is self limiting.
This entire thread boils down to that simple issue.
Willis Eschenbach says:
August 18, 2011 at 10:47 am
Perhaps that works with your friends, Roger, that you wave your hands and say that the dance of the photons is what keeps DLR from warming the ocean, and that the photons are dancing because of an invisible mist above the water … around here we need a bit more than that.
Hi Willis, the tone setting and hand waving you did earlier in this thread seemed to work for you. However I don’t see too many of the back slappers and me-toos left here defending the physically untenable. I’ll come to that.
Perhaps you think sea fogs appear out of thin air?
I think they happen when sub-visible water vapour already present in the air above the sea surface cools and condenses. You can prove this one for yourself in a kitchen experiment. A pan of water which has the heat under it reduced suddenly will get a mist of visible steam suddenly appear on its surface. This isn’t happeneing because more water is evaporated when the heat is reduced WIllis. It’s happeneing because the sub-visible water vapour molecules condense and agglomerate due to the reduction in available energy.
What is the second “distinct process” that the DLR is doing that I’m conflating with DLR hitting something and warming it?
The longwave flux keeps the air warmer than it would otherwise be by thermalising water vapour and co2. This reduces the temperature differential between the sea surface and the air. That slows down the cooling of the ocean. Not by very much, but is is a real physical effect.
TB-“I don’t think DLR striking the surface can heat the bulk of the ocean, and neither does Tim, for all the reasons we’ve rehearsed several times on this thread and many others.”
That’s because you refuse to see that when something “slows down the cooling of the ocean”, the bulk of the ocean ends up warmer. We call that “warming the ocean”, and yes, it occurs simply by slowing the cooling.
That is the effect of the physically distinct process outlined above. Thanks for agreeing that we are talking about ‘slowing the cooling’ rather than ‘heating’.
TB-“LW Radiation only penetrates a few nm.
Conduction can’t go downwards because the surface is cooler than the subsurface.”
You’re looking at this backwards. In a system in which the surface is maintained at a slightly lower temperature than the bulk … what happens if you forcibly warm the surface? Think it through all the way, Roger. The very surface warms … until it’s slightly warmer than the bulk … which then heats up slightly, until the surface is slightly cooler than the bulk, and the previous condition (cooler surface) is restored.
I think this is handwaving for which there is plenty of refuting observational evidence in the literature. It’s more imaginitive than your earlier effort though.
Unless your claim is that such a system can’t be heated from the top … but I don’t think that’s your claim.
On the rare occasions the air is warmer than the water, it can be heated from above to a very limited extent by conduction.
TB-“Turbulent convection isn’t significant because if the eddies aren’t strong enough to pull down fingernail sized pieces of saturated toilet paper then they’re not strong enough to survive destructive interference beyond a few inches. Take it from someone who has designed centrifugal pumps.”
Have you ever seen the ocean? There’s turbulence there that will pull down a swimmer, much less fingernail sized pieces of paper. Wind plus ocean equals turbulence that sinks ships, so I haven’t a clue what your claim means, or what designing pumps has to do with it.
I lived on a sea going boat I restored for seven years. I have done a lot of swimming in it, and I’ve never been sucked under in the open sea. The eddies you are talking about take place in tidal rips and down channels between land masses. There’s a lot more open ocean than coastal places where such mayhem can occur. Ship sinking waves on the open sea do occur, but winds that strong and freak waves are rare. I specified the conditions of my experiment and they hold good for the majority of conditions short of breaking wave tops in the open sea. When designing the involute curve of a centrifugal pump casing, you match the velocity of the water flow to the radius it travels round to minimise cavitation and vorticity which forms eddies. This is because eddies interfere with each other and make the flow turbulent, reducing velocity, promoting wear and requiring more power to shift the fluid. I understand the way water moves under various kinds of impelling forces. Turbulent convection at the ocean surface in open water under non-white-top conditions is negligible in terms of forcing warmer packets of water down into cooler.
TB, because the ocean can only lose energy through the top, the top is always slightly cooler than the layer below.
What seems to have escaped you is that this setup, cooler water on top of warmer water, is inherently unstable because the cooler water is denser than the warmer, and it wants to sink, and does so. The cooler surface is kept in existence by water moving to the surface, cooling, sinking a mm or so, rewarming, rising to the surface, cooling, sinking a mm or so, and so on.
I agree that natural convection is continually taking place. It doesn’t help your contention that heat moves downwards from the surface though, because what you have just described is heat moving upwards.
So rather than being thermally isolated from the bulk below as you seem to be claiming, the cooler skin surface is constantly exchanging energy and water molecules with the bulk ocean below. And of course, because of that, any radiation absorbed by the skin surface affects the heat loss (and perforce the temperature) of the bulk of the upper ocean.
I haven’t claimed anything of the sort. Energy is constantly being exchanged, upwards. You are correct that radiation absorbed by the skin surface affects the heat loss, and in combination with the upward long wave radiation, the flux leads to a cooling of the surface by around 66-70W/m^2. However, there are other factors which also maintain the skin temperature and subsurface gradient which are larger in sum than radiation effects.
In other words, the DLR doesn’t need to penetrate to the depths in order to warm the depths.
It can’t penetrate to the depths and it can’t warm the depths through direct interaction with the ocean any more than negligibly. As part of the long wave flux in the air, a change in the amount of DLR relative to ULR can cause the ocean to cool marginally more slowly, though the size of the effect will be small compared to convective and albedo changing processes.
Cheers
TB
[blockquote] Willis Eschenbach says:
August 18, 2011 at 10:24 am
I have pointed out a number of times how radiation on the top skin layer of the ocean can affect the bulk temperature of the ocean, regardless of the temperature of the skin surface. It does so by slowing the cooling of the ocean, which increases the temperature of the bulk ocean.[/blockquote]
Sorry, but “slowing the cooling” is not “increasing the temperature “. The temperature is still going *down*, whereas an increase in temperature is in the opposite direction.
RE: Myrrh: (August 18, 2011 at 2:11 am)
“‘Visible light is only PARTIALLY transmitted through water, a fact which is obvious if you ask why is is completely dark below a certain depth’
“Because energy from the Sun isn’t eternal. Because matter slows down light. Water is matter, the deeper you go the greater the pressure. When you switch off your table lamp, where does the light go?”
It appears that you are suggesting that photons after going so far through the water just get tired and wink themselves out of existence. Not quite–conservation of energy applies.
Even though the water is transparent, the chance of photon making it through any given length is always less than 100 percent. Eventually that photon is going to be captured in the water or on the bottom. That will make the capturing molecule warmer by an amount proportional to the frequency of the photon. That ‘lucky’ molecule will then share the energy of its ‘catch’ with all its neighbors.
The only exception to this will be those lucky photons that strike a reflecting surface and make it all the way back up out of the water. In deep water there is very little hope of this.
“Sorry, but “slowing the cooling” is not “increasing the temperature “. The temperature is still going *down*, whereas an increase in temperature is in the opposite direction.”
“slowing the cooling” can lead to a temperature increase in cases where there is a continuous input of energy. To use one of those analogies which plague this area, consider a dam which has a steady inflow of water, but there are several leaks in the dam. Now plug one of the leaks (slowing the leaking), and what happens – the water level rises, increasing the amount stored, until it finds a new leak. In terms of heat/temperature , if you have a continuous input of energy, and you slow the rate of departure a bit, then one of the heat sinks in the system will fill up a bit (warm), until a new equilibrium is reached. So the two ideas, “warming” versus “slowing cooling” are not as disjoint as it appears.