A new approach to solve correlated k-distribution function

The resorting profile of absorption coefficient is fitted with Voigt function by employing the similarity between it and a single mixed broadened Voigt line type. In this way, simple mathematical fitting formulae are obtained to solve k-distribution (k-D) function at any pressure and temperature. Thus, a new correlated k-D method is proposed on the basis of it. Finally, taking mid-latitude summer atmosphere as an example, longwave cooling rates are calculated for three major gases by the new method, and then compared with the corresponding results by line-by-line integration.