Convective processes profoundly affect the global water and energy balance ofour planet but remain a challenge for global climate modeling. Here wedevelop and investigate the suitability of a unified convection scheme,capable of handling both shallow and deep convection, to simulate cases oftropical oceanic convection, mid-latitude continental convection, andmaritime shallow convection. To that aim, we employ large-eddy simulations(LES) as a benchmark to test and refine a unified convection schemeimplemented in the Single-column Community Atmosphere Model (SCAM). Ourapproach is motivated by previous cloud-resolving modeling studies, whichhave documented the gradual transition between shallow and deep convectionand its possible importance for the simulated precipitation diurnal cycle.Analysis of the LES reveals that differences between shallow and deepconvection, regarding cloud-base properties as well asentrainment/detrainment rates, can be related to the evaporation ofprecipitation. Parameterizing such effects and accordingly modifying theUniversity of Washington shallow convection scheme, it is found that the newunified scheme can represent both shallow and deep convection as well astropical and mid-latitude continental convection. Compared to the defaultSCAM version, the new scheme especially improves relative humidity, cloudcover and mass flux profiles. The new unified scheme also removes thewell-known too early onset and peak of convective precipitation overmid-latitude continental areas.
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