Atmospheric water vapor measurements at 6–7 microns from a satellite

Abstract

Measurements from an artificial satellite of the long wavelength (terrestrial) radiation emitted and reflected from the earth and its atmosphere should offer some insight on the vertical distribution of temperatures and on the strati~cation of the radiating gases”). The intensity of the total spectrum from about 5 to more than 100~ will not be very useful for his purpose. It is necessary to separate narrow spectral bands by means of filters or even spectrometers. As a partial problem, we will investigate the kind of information yielded by a measurement within the water vapor spectrum-either in the ~6.3~ band or somewhere in the rotation band. We will not enter here into inst~men~l details but simply assume that we have at our disposal a device to measure the radiation between 6 and 7,~ Then the radiation shall be computed which within this wavelength band is emitted by the atmosphere to a suitable radiation receiver outside the atmosphere. The atmosphere is considered to be horizontally stratified in parallel and plane layers. The curvature of the earth’s surface as well as of the radiation beams is neglected. In this spectral region only the water vapor must be taken into consideration as a radiating gas. The water vapor mass may be defined by