Edward O. Hulburt
worked out a pioneering example of such a "radiative-convective" model in 1931.
Hulburt, a senior physicist at the Naval Research Laboratory, had a general interest in the structure of the upper atmosphere through his professional work on radio propagation and the ionosphere.
Taking a brief excursion away from matters that interested the U.S. Navy
carried out a one-dimensional calculation, using data on the absorption bands of CO 2 and water far better than what was known in Arrhenius's time.
first attempt, Hulburt
came up with an unreasonably high surface temperature.
realized that this was because he
had considered only the transfer of radiation up through the atmosphere.
If the lower atmosphere were actually so hot it would be unstable - the hot air would rise.
put in a crude measure for transfer of heat by convection.
got a figure that agreed with Arrhenius's rough estimate that doubling or halving the amount of CO 2 in the atmosphere would raise or lower the Earth's surface temperature several degrees
Unaware of the modern data that Hulburt
had used, they believed that laboratory measurements at the turn of the century had proved that the CO 2 and water vapor in the atmosphere already blocked infrared radiation so thoroughly that adding more gas would make no difference.
Critics also pointed out that Callendar, like both Arrhenius and Hulburt
, had not considered how a warmer and moister planet might have more clouds, which could reflect sunlight and maintain a cooler temperature.
had attempted to work through this, but even if the experts had noticed his
publication they would have found it too primitive to prove anything.
Möller's model, and all the earlier calculations back to Arrhenius (aside from Hulburt's
overlooked paper), had been flawed because they failed to take proper account of this basic process.(15*)
Whereas Arrehnius had left out convection, Hulburt
left out water-vapor feedback, and neither had good absorption data.
My thanks to S. Manabe for comments on this.
As late as 1967, when Manabe carried through the correct convection calculation, he
was unaware of Hulburt's work: personal communication, Jan. 28, 2008.
Arrhenius further had inadequate data for water vapor absorption, while Callendar and Plass as well as Hulburt
left out the water vapor feedback altogether.
(1931) . BACK