On the equivalence of two schemes for convective momentum transport

Abstract

The Gregory-Kershaw-Inness (GKI) parameterization of convective momentum transport, which has a tunable parameter C, is shown to be identical to a parameterization with no pressure gradient force and a mass flux smaller by a factor of 1 2 C. Usingcloud-resolving simulations, the transilient matrix for momentum is diagnosed for deep convection in radiative-convective equilibrium. Using this transilient matrix, it is shown that the GKI scheme underestimates the compensating subsidence of momentumby a factor of 1 2 C, as predicted. This result is confirmed using a large-eddy simulation.©2012 American Meteorological Society.