Analysis of variability in divergence and turn-over induced by three idealized convective systems with a 3D cloud resolving model

Abstract. The sensitivity of upper tropospheric and lower stratospheric convective outflows and related divergence fields is analysed using an ensemble of cloud resolving model (CM1) simulations in LES-mode including various physically manipulated simulations for three different convective systems initialized with an idealized trigger. The main goal of this study is to assess to what extend the divergence field depends on cloud microphysical processes, the mode of convection and on the processes of convective momentum transport and moist static energy redistribution. We find that latent heat release (representing the microphysical uncertainty) plays an essential role by explaining much of magnitude of the divergence field that will be formed. Convective organisation explains another important fraction of the variability in the divergence field that is formed by a convective system and behaves non-linearly, likely partly via condensation and subsequent (re-)evaporation/sublimation. The detrainment of stratospheric air also shows large sensitivity among the experiments.