Implementation of the Ferrier cloud microphysics scheme in the NCEP GFS

Masayuki Nakagawa
JMA Visiting Scientist


The Ferrier cloud microphysics scheme used in NAM (Ferrier et al. 2002) was tested for GFS with the intent to replace the scheme of Zhao and Carr (1997) currently used in GFS. It is necessary to introduce consideration of fractional cloud coverage in a grid box for use in GFS, since the Ferrier scheme is designed for use in high-resolution mesoscale model and do not consider partial cloud explicitly.

We have performed data assimilation experiments of the scheme for a two-month summer season of 2008 and for a two-month winter season of 2010. We will present the details of the treatment of partial cloud in the Ferrier scheme and the results of the evaluation.