Parameterization of transmission functions in problems of radiative transfer in the Earth's atmosphere

ABSTRACT This paper generalizes the results of development of few-parameter models of transmittance, which provide both the needed accuracy close to that given by the LBL method and the high computational speed. Particular emphasis is placed on the latest advances connected with the Laplace transformation and presentation of the transmission function as exponential series.Keywords: absorption, transmission, radiative transfer, atmosphere, line by line, k-distribution, longwave radiation 1. INTRODUCTION Radiative processes play an important part in the global climate. They are connected with such factors as variations of thesolar constant, transformation of surface properties, changes of the gas and aerosol composition of the atmosphere, and soon [1]. The global climate change is now associated with greenhouse gases C02, CH4, N20, and freons, the doubling ofwhose concentration changes the outgoing thermal radiation flux by about 1 %. These data give a general idea on whataccuracy of solution of the transfer equation is required in the problems of climate simulation. On the other hand, thecharacter of the problems of general atmospheric circulation imposes strict requirements on the computation speed of