Impacts of the cloudiness formula in weather and climate prediction

Clouds are important elements affecting the climate system. In particular, accurate parameterization of clouds and their radiative properties are essential in order to produce realistic illustrations of the current climate and credible predictions of possible future climates. Many efforts have been made to improve the cloud-radiation interaction in general circulation models (GCMs); these including improving the cloudiness parameterization itself, and producing a better representation of cloud microphysical processes related to the cloud-radiation properties in a GCM. However, it is still unclear which process is a major factor responsible for the large-scale motion associated with convective processes. The purpose of this study is to investigate the effects of the fractional cloudiness formula in a GCM on a simulated climate. This study attempts to develop new parameterization method to the cloud-radiation processes within the framework of traditional approach, and addresses the investigation of its impact on the cloud-radiation processes.