Large-eddy simulation of spatial transitions of stratocumulus- to cumulus-topped boundary layers

Abstract:

The cloud–circulation feedback in global circulation models is the one of the largest sources of uncertainty in climate projections. The accurate prediction of the shallow clouds response in a warming climate remains elusive with significant implications for future projections and mitigation plans. The interplay between the large-scale circulation dynamics and convection is typically manifested in studies of cloud-regime transitions. For instance, stratocumulus transitioning into cumulus. Using a series of large-eddy simulations the spatial cloud transition from stratocumulus to cumulus is studies. Budgets of mass and energy are used to elucidate the state of the boundary as it advects and transitions over warmer sea surface temperature. The impact of the horizontal turbulent transport is also assessed. Horizontal turbulent transport is not present in Lagrangian modeling setups and neglected in convection parameterizations.