Large-eddy simulation and parametrization of the effects of shear on shallow cumulus convection

Large-eddy simulations are performed of ensembles of shallow convective clo uds under varying shear. The scalar transports are shown to be largely unaf fected by shear, while the momentum transport is strongly affected. The par ametrization of the momentum fluxes is discussed. The cross-cloud pressure gradient, commonly neglected in shallow cumulus parametrizations, is shown to be a dominant term in the in-cloud momentum budget. The performance of t wo possible representations of this pressure gradient, each previously prop osed for use in deep convection parametrizations, is assessed.