Methods of Estimating Infrared Flux and Surface Temperature from Meteorological Satellites

Abstract

Abstract The TIROS II meteorological satellite carried a multiple channel radiometer of medium resolution (about 5 deg). Two of the channels were designed to measure the upward radiation in the “window” at 8–12 microns, and over the broad spectral region of 7–30 microns. To deduce surface temperatures and total upward flux values from the measurements in these two channels, additional operations must be carried out on the data. As a basis for these transformations, the specific spectral intensity over the entire infrared region was calculated at five zenith angles for each of 106 atmospheric models. In the 7–30 micron channel, an empirical relation was found to transform measured values to total intensity; and, from the limb-darkening exhibited by the 106 individual models, a method of calculating flux was formulated; in this case, the results contain inaccuracies of only about two per cent attributable to the method used. In the 8–12 micron channel, the influence of ozone and water vapor was determined f...