Modeling of the radiative process in an atmospheric general circulation model

A new radiation scheme has been developed for dynamic general-circulation modeling. An automatic determination of k-distribution parameters and a treatment of solar-terrestrial radiation interacting with gaseous and particulate matter are incorporated into the scheme by a technique that combines discrete ordinate and matrix operator methods. An accelerated scheme for cloud overlap is developed and tested. The resultant accuracy of the scheme is ?0.5 K/day to a 70-km height in clear sky better than that of the line-by-line calculation method.