Vol. 17, issue 11, article # 7

Abstract:

This paper describes the statistical algorithms for calculation of solar spectral fluxes in the atmosphere under clear-sky and overcast conditions, as well as for the case of broken clouds. These algorithms are based on the representation of the transmission function of atmospheric gases in the form of an exponential series (k-distribution method). Molecular absorption coefficients are calculated using the HITRAN-2000 database with the allowance made for instrumental functions of the measurement facilities used, real meteorological parameters of the atmosphere, and gas concentration profiles. To test these algorithms, we compare our results with the reference data of line-by-line calculations of the up and downwelling fluxes for the clear sky and to the data of field measurements under overcast conditions. It is shown that the algorithms proposed are highly accurate and easy in computer realization.