Convective Parameterization for Mesoscale Models: The Kain-Fritsch Scheme

Abstract

The Kain-Fritsch (KF) convective parameterization scheme (CPS) is based on the same fundamental closure assumption as the Fritsch-Chappell (FC) (1980) scheme—convective effects are assumed to remove convective available potential energy in a grid element within an advective time period. Its development was motivated by ongoing observational and numerical investigations of mesoscale convective systems that have revealed the potentially significant impact of certain physical processes that were not represented in the FC scheme. For example, in the FC scheme, detrainment from convective clouds to their environment occurs over a limited vertical depth near cloud top. Yet, it has become evident from diagnostic studies (e.g., Leary and Houze 1980; Gamache and Houze 1983) that midlevel detrainment of mass and moisture from deep convective clouds plays an important role in the development of some mesoscale convective systems.