Accounting for the Overlap of Molecular Absorption Spectra of Different Gases in the Approximation of Transmission Function by a Series of Exponents

A new method is proposed for accounting for the overlap of absorption bands of different gases in the approximation of the transmission by a series of exponents. The method takes additively into account the effective molecular absorption coefficients of various gases. It is shown that this method makes it possible to obtain short exponential series (small number of parameters), that ensures high speed of the calculation of radiative transfer in the Earth’s atmosphere. The developed method is applicable to the radiative transfer simulation in both the longwave and shortwave spectral regions, including cases of multiple scattering by aerosol and cloud particles.