Can longwave radiation heat the oceans?

[Bystander]

Are you only interested in the direct warming by IR?

The "interest" is in seeing/finding/determining the "state of the art" regarding energy balances and uncertainties in the various radiation energy exchange/transfer mechanisms among surface, atmosphere, and oceans.

 

[FactChecker]

Bystander - I found the following passage on a CAGW skeptic's website (http://climaterealists.com/index.php?id=4245)
"However the effect of downwelling infrared is always to use up all the infrared in increasing the temperature of the ocean surface molecules whilst leaving nothing in reserve to provide the extra energy required (the latent heat of evaporation) when the change of state occurs from water to vapour. That extra energy requirement is taken from the medium (water or air) in which it is most readily available. If the water is warmer then most will come from the water. If the air is warmer then most will come from the air. However over the Earth as a whole the water is nearly always warmer than the air (due to solar input) so inevitably the average global energy flow is from oceans to air via that latent heat of evaporation in the air and the energy needed is taken from the water. This leads to a thin (1mm deep) layer of cooler water over the oceans worldwide and below the evaporative region that is some 0.3C cooler than the ocean bulk below."
The last sentence does seem to be validated with this paper: http://www.nature.com/nature/journal/v358/n6389/abs/358738a0.html
But is the rest fair?

I think this analysis must be close to the answer. The latent heat of evaporation must be a big player in this. If the surface temperature consistently remains below the lower temperature, that implies that light frequencies which can penetrate to lower levels are enough to maintain a steady heat transfer up to the surface. But clearly the IR warming the surface must reduce the rate of heat transfer. So IR indirectly allows the lower layers to stay warmer than otherwise.

 

[Bystander]

must be close to the answer

Possibly. It would be a more compelling argument with some actual numbers. As it stands, it's difficult to distinguish from a variety of perpetual motion schemes that run the energy around in circles with qualitative explanations to the point that no energy balance is possible.

 

[FactChecker]

Possibly. It would be a more compelling argument with some actual numbers. As it stands, it's difficult to distinguish from a variety of perpetual motion schemes that run the energy around in circles with qualitative explanations to the point that no energy balance is possible.

"perpetual motion schemes"? What are you referring to?

 

[Bystander]

"perpetual motion schemes"?

IR evaporates surface film, warming atmosphere, which emits IR, which evaporates surface film ... ? Bothers me.

 

[Loudzoo]

Bystander - many thanks for your time on this. I too have been hunting for some actual data but am yet to find much. What little I have found (such as this: http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-11-00262.1) suggests to me that the additional 1 watt / m^2 downward longwave radiation at sea level that doubling CO2 atmospheric concentrations would generate cannot be easily traced within the context of +/- 10 watts / m^2 errors in measurements. Furthermore, an additional 1 watt / m^2 in the context of an average of 350 watts / m^2 is unlikely to affect long term warming rates of the ocean even if you could measure to that level of accuracy . . .

 

[Bystander]

Comparing total insolation (1363 ± 0.05 to ± 0.08% variation over 11 year solar cycle) to GMT isn't getting me anywhere either. Should be a 10 -15 mK "scallop" showing up in GMT, GISS other temperature records with ~ 11 year period, and if it's there, it's not obvious. May be too far below the noise level of the original measurements.

 

[PeterDonis]

the additional 1 watt / m^2 downward longwave radiation at sea level that doubling CO2 atmospheric concentrations would generate cannot be easily traced within the context of +/- 10 watts / m^2 errors in measurements.

This is an issue with many key measurements of the climate: the effect that is supposedly there is smaller (sometimes much smaller) than the error in the measurements.

 

[Bystander]

the effect that is supposedly there is smaller (sometimes much smaller) than the error in the measurements.

At which point we've about exhausted this discussion? And should give up and lock it?