Remote Sensing of Cirrus Cloud Compositions from Satellites.
UTAH UNIV SALT LAKE CITY DEPT OF METEOROLOGY
Pagination or Media Count:
Comprehensive description of the discrete-ordinate method for the transfer of infrared radiation in an isothermal cloud layer is presented. Applications of such a method to non-isothermal, inhomogeneous atmospheres containing cirrus clouds are carried out and a listing of the computational code of the infrared radiation program is given in the Appendix of this report. On the basis of this radiation program which allows non-isothermal as well as non-homogeneous structures of clouds, radiative properties of cirrus clouds are investigated in the 10 micrometers window region. Effects of non-isothermal structure of cirrus are shown to be important when its thickness is greater than about 3 km. In addition, we also find that it seems inappropriate to define an emissivity of a non-isothermal cloud. Utilizing the concept of transmissivity derived from radiative transfer analyses, a retrieval technique is developed for the determination of the surface temperature, the cirrus cloud thickness and its transmissivity at a reference wavenumber and the fraction of cirrus cloudiness. Error analyses employing climatological data reveal that independent random errors in temperature and humidity profiles introduce insignificant errors in the four resulting parameters. Based on the retrieval procedures we illustrate that the vertical ice content may be estimated assuming that ice particles are randomly oriented in a horizontal plane. Author
- Infrared Detection and Detectors