Abstract
This paper discusses the climate-dependency of three coefficients in general long wave radiation equations and the validity of the cloudiness factor in general equations, based on data at 18 high accuracy stations for long wave radiation fluxes. The following became apparent: (1) two coefficients of Brunt's formula for the air humidity correction factor under clear-sky conditions have a correlation coefficient of −0.98; (2) the coefficient of the Brunt's formula has a correlation with annual mean vapor pressure and is assumed to be climate-dependent; (3) the coefficient of the original cloudiness factor which is a linear function of a rate of short wave radiation under a clear sky to actual short wave radiation have a correlation with annual mean vapor pressure and annual mean air temperature and is also climate-dependent; (4) the cloudiness factor in general equations is considered as the fitting parameter which considers not only cloud radiation but the temperature difference between air and surface.
