A forced gravity wave model of self-organizing convection

Abstract

A two-dimensional, hydrostatic, nonrotating numerical model with a cumulus parameterization is developed to study the early stages of mesoscale convective systems. Amplifying, forced gravity waves occur when penetrative downdrafts are present. Updraft heating by itself is unable to cause convective systems to intensify. Propagation speeds are in rough agreement with those observed in midlatitude mesoscale convective systems. The conditionality of the convection and the horizontal advection of precipitation by the relative wind produce lags between lifting and convection that are not found in conventional wave-CISK models. These lags show the growth and reduce the propagation speeds of forced gravity waves. -from Author