EMISSIVITIES OF NATURAL SURFACES AND SURFACE TEMPERATURE

A simple method of determining emissivity of surface using Eppley pyrgeometer in situ is presented to evaluate surface temperature exactly.The indicated temperature of radiometer needs corrections for actual sky thermal radiance and for true surface emissivities.Comparisons between radiation temperature and surface mercury-thermometer temperature at Nagqu,northern Tibet during December 1985-January 1986 have shown that their differences are mostly within 2-4℃.