Direct Absorption of Solar Radiation by Atmospheric Water Vapor, Carbon Dioxide and Molecular Oxygen

Abstract

Based mainly on Howard, Burch and Williams' laboratory absorption data for the near infrared H2O and CO2, bands, and on the solar absorption data for the red and near infrared O2 bands, the direct absorption of solar radiation in near infrared atmospheric bands has been estimated. The estimated absorptivities of the H2O bands in the interval from 0.7 to 2.1 ? are in fair agreement with MeDonald's estimates which are based on Fowle's absorption data. However the absorptivities of the H2O bands from 0.7 to 6.3 ? are larger than McDonald's values. CO2 and O2 absorptions become increasingly important in the upper troposphere and in the stratosphere. Average heating (deg C day?1) was also estimated for London's model atmospheres for clear sky conditions, and compared with the similar estimate made by Roach. For the atmosphere above 300 mb the heating estimated in this paper exceeds that estimated by Roach. Conceivable causes of this discrepancy are pointed out.