Discussion > Can Back Radiation Warm the Oceans
Can there be any other way for the heat supposedly created by back radiation to warm the ocean depths?
Obviously direct solar heating by short wave radiation and long existing natural convection currents are not part of process.
Jun 1, 2013 at 2:30 PM RKS
I think the concept of "back radiation" warming things came from Climate Scientists who either did not understand physics or at least were not good at explaining it.
As a result, enormous effort has been soaked up in discussing whether or nor back radiation warming things is physically possible.
In the simple GHE model (Earth = black body enclosed by a thin shell of gg close to the surface) the setup can be analysed without the need to invoke the idea of backradiation warming anything. If you start the analysis with a cold Earth and the Sun is switched on at t = 0, the Earth warms until it reaches equilibrium. After that, everything is at constant temperature, so nothing is then being warmed any further In analysing the transient situation prior to reaching equilibrium, all of the warming is done by incoming short wave radiation. In equilibrium, with everything at constant temperature, although the back radiation is there, rattling back and forward, it's not doing any warming.
I don't know if this makes sense as I've explained it. I hope it does.
If it does, can your question be reposed without using the concept of back radiation which I think would lead to all sorts of inconclusive argument.
[Personally I think the idea of the GHE warming the deep ocean without first warming the surface is total nonsense, since the GHE is exists so that (according to the simple model) the surface can radiate a total power equal to the incoming power. It's utter bollocks - to give my scientific assessment - to talk about the deep ocean getting warmed while the surface stays a bit chilly.]
Martin A
Thanks for both of parts of that Martin. We shouldn't be using 'back radiation' as a phrase any more. And 'the GHE warming the deep ocean without first warming the surface is total nonsense' sums the situation up from where I stand.
Richard Drake
If it does, can your question be reposed without using the concept of back radiation which I think would lead to all sorts of inconclusive argument.
[Personally I think the idea of the GHE warming the deep ocean without first warming the surface is total nonsense, since the GHE is exists so that (according to the simple model) the surface can radiate a total power equal to the incoming power. It's utter bollocks - to give my scientific assessment - to talk about the deep ocean getting warmed while the surface stays a bit chilly.]
Jun 1, 2013 at 3:00 PM | Martin A>>>>>>>>>>>>
I'm in agreement with you.
You'll notice I used the term "Can there be any other way for the heat supposedly created by back radiation to warm the ocean depths?" as the "supposed" heating of the oceans is by the properties of man made CO2, which is "supposed" to heat the surface, whether land or sea, by back radiation.
As with you I find the supposed heating of the oceans by back radiation to be utter bollocks, but I'm interested in any argument to back up the [nonsensical] proposal that heat, supposedly caused by man made CO2, is somehow penetrating the oceans to a depth way beyond even that of the Argo buoys.
RKS
Any chance of mothballing this discussion and beginning one that doesn't mention back radiation then, RKS?
Richard Drake
Any chance of mothballing this discussion and beginning one that doesn't mention back radiation then, RKS?
Jun 1, 2013 at 3:28 PM | Richard Drake>>>>>
OK
I must somehow make reference to the AGW advocates case though as the supposed heating is supposed, by them, to be by man made CO2.
RKS
Thanks, much appreciated. I've seen no credible explanation of this so perhaps no responses to Does man made CO2 cause ocean warming - well, apart from "Very, very little" - would be the right result. :)
Richard Drake
WUWT has carried out a couple of kitchen-sink experiments on "back-radiation" - entertaining stuff:
http://wattsupwiththat.com/2013/05/28/slaying-the-slayers-with-watts-part-2/
mikeh
Thanks Mike, I'd missed that (like so much else) - tremendous.
Richard Drake
RKS,
I find the easiest approach is just to consider the path-length of IR (thermal) radiation. In water, especially sea water, it is tiny. It barely breaks the surface (Visible and UV go further, but that is sunlight).
In the unlikely event that Trenberth's missing heat is hiding deeper in the oceans, it certainly didn't get there by thermal-radiative means, sneaking past the Argo buoys. That would indeed be bllx in my opinion.
michael hart
I thought I read somewhere that a proposed mechanism for deep ocean heating was some sort of thermal plunging effect where surface water is propelled to depth by some mechanical means. Sounds clutching to me (wouldn't the hotter water cool as it went down, transferring its heat to the surrounding colder water which would then rise?) but I think that was one proposed mechanism.
I've always thought the "hiding in deep water" explanation was just putting it in the place we find hardest to measure - i.e. if heaven isn't above the clouds, it must be in space, or another dimension.
TheBigYinJames
As a complete aside on a thread that I asked to be mothballed, TBYJ, I recommend CS Lewis on metaphor ancient and modern on 'heaven above the clouds'. Bottom line (so to speak): ancients that wrote like this would not have been phased by something as crude as a physical spacecraft not locating or arriving in heaven. A deep matter. And you're right about the deep water. Though of course Leviathan is there, spatio-temporal chaos personified. :)
Richard Drake
AGW fanatics are becoming ever more shrill in their argument that the 'missing heat' as they put it MUST be somewhere in the oceans.
Unless I'm informed wrongly, the Argo buoys show otherwise but my problem with their proposal is simply that infra red back radiation from man made CO2, the supposed reason for AGW, cannot penetrate more than a few microns beneath the surface of the water and any heat generated would be immediately evaporated with, or without, the aid of winds.
Can there be any other way for the heat supposedly created by back radiation to warm the ocean depths?
Obviously direct solar heating by short wave radiation and long existing natural convection currents are not part of process.