TIROS III RADIATION MEASUREMENTS AND SOME DlABATlC PROPERTIES OF THE ATMOSPHERE*

Abstract

A basic objective of this study was to evaluate the applicability of medium-resolution satellite radiation measurements to assessments of the diabatic heating and cooling within the atmosphere. Data from portions of TIROS III orbital passes in mid-July 1961 and concurrent conventional data were examined over a 4-by-4-degree grid scale. Computations, appropriate to analyzed cloud conditions for each grid block, included the outgoing long-wave flux, the infrared radiational cooling, the total radiational cooling (including solar absorption in the atmosphere), and the total potential energy. In addition, simple relative estimates were made of the latent heat released and the average boundary heat flux into the atmosphere. Results show that, for nadir angles less than about 45 deg., the unaltered Channel 2 temperature is proportional to the computed outgoing long-wave flux and is related to the average cloudiness in each grid block. The Channel 2 temperature has a higher positive correlation with the total radiational cooling (long-wave and short-wave) in the atmosphere than with the long-wave cooling alone. The relative heating from the distributions of net radiation and precipitation are correlated in the same sense to the Channel 2 temperature, but the relative boundary heat flux is correlated in the opposite sense. Unaltered Channel 3 fluxes show a general relationship to atmospheric solar absorption rates and to a cloudiness parameter for the grid scale. Some slight generation of eddy potential energy was suggested by the analyses of the differential diabatic cooling.