Convective cumulus clouds with vigorous updrafts and downdrafts form thunderstorms. Severe thunderstorms consist of multiple thunderclouds at different stages, and the storm itself has a longer lifetime than individual cells. As the convective clouds grow larger, the negative charge accumulates in their lower region, and the positive charge in the upper level forms a dipole. When the charge...
Cold pools are essential for organizing and initiating convection. In a recent investigation, we identified several sensitivities of cold pool driven convective initiation to model resolution within hectometer simulations. In particular, a causal graph analysis has revealed that the dominant impact of model resolution on convective initiation is a direct consequence of weak...
The organization of convective clouds has been argued to have a significant impact on the atmospheric humidity and circulation, as well as precipitation and cloud radiative feedback, yet global models do not include a parameterization of unresolved subgrid cloud structure. In this study, we investigate the necessity of including subgrid scale cloud structure in the model and whether it...
About 15 years ago, Cohen and Craig (2006, CC06) proposed a general theory describing the fluctuations of the properties characterising a convective cloud ensemble developing under fixed external forcing. This theory later served as the basis of the Plant-Craig stochastic convection scheme which has been in particular implemented in the ICON model operated by the German weather service....
In observations of (sub)hourly precipitation, it is often found that the extremes display a dependency on (dew point) temperature exceeding the Clausius-Clapeyron (CC) relation. Such super CC behaviour is commonly explained by dynamical feedback mechanisms in convective clouds whereby enhanced latent heating (and cooling due to evaporation) could produce more vigorous, or more organised...
Cold pools formed by convective downdraughts can feed back onto the organisation and diurnal cycle of convection. This presentation describes a parametrisation of cold pools, C-POOL, recently developed within the Met Office Unified Model (UM). The parametrisation includes forcing by downdraughts, dissipation, and various pathways for influencing parametrised convection in the UM. It also...
