There has been some progress in the greenhouse. On the ‘toy planet’ thread, physicist Tim Folkerts now agrees with me that longwave infra-red radiated from the air towards the surface doesn’t directly heat the ocean but makes it harder for the ocean to cool. In my view this is due to IR radiation from the ocean making the air warm, reducing the temperature differential between ocean and air, slowing the rate of the Sun warmed ocean’s heat loss. Tim says:
LWIR is indeed incapable of “heating” the oceans in the strict sense of the word (net transfer of thermal energy). The best it can do is aid in making it “a far more difficult task escaping” for the energy.
But it’s hard for him to let go of ingrained notions, so his next comment is full of ambiguities, which I have tried to deal with in my followup comment:
Tim Folkerts: The DWIR DOES amount to ~ 330 W/m^2.
Fine, no problem.
This energy DOES get absorbed by the ocean.
In the top few microns, and is soon re-emitted along with an additional ~60W/m^2 IR, upwards.
The ocean IS warmer than it would be without this DWIR from the atmosphere.
But not because it is absorbed and re-emitted from the top few microns of ocean. The thermalisation of IR in the bulk air helps keep the air warm and that warm air slows the sun warmed ocean’s heat loss.
But the reason the air is warm is because the ocean warms it with the energy it emits into it which is absorbed and re-emitted, or conducted to the O2 and N2 in the air, by water vapour (from the ocean) and co2 (mostly from the ocean). Air has very little heat capacity of its own, and is nearly transparent to incoming solar short wave radiation. And this ocean warmed air is usually convecting upwards.