| Description |
The long wave thermal radiation flux density leaving the planet earth is determined for varoius meteorological air masses. Emission of infrared radiation by the surface of the earth as modified by eater vapor, carbon dioxide, and ozone is calculated by means of Elsasser radiation charts. The meteorological data used are those given by Petterssen, which do not represent climatological means, by certain typical situations. Lacking exact descriptions of the water vapor structure of the stratosphere, flux densities are calculated for two variant conditions, a dry and a moist stratosphere. Little difference results. It is assumed that all air masses, except those of distinctly dry character, might include clouds whose tops are found at one of the following levels: 800 mb, 700 mb, 500 mb, 300mb, and 200 mb. Hence flux densities are calculated for clear and clouded sky, with the result that cloudtop data are found to be extremely important. Since the soundings contain only shelter temperatures, whereas soil temperatures are needed, seven different temperatures for the ground are assumed for each individual case. Ground temperature is shown to be very important. |
