Counter-Gradient Momentum Transport Through Subtropical Shallow Convection in ICON-LEM Simulations.

ABSTRACT: It is well known that subtropical shallow convection transports heat and water vapor upwards from the surface. It is less clear if it also transports horizontal momentum upwards to significantly affect the trade winds in which it is embedded. We utilize unique multiday large-eddy simulations run over the tropical Atlantic with ICON-LEM to investigate the character of shallow convective momentum transport (CMT). For a typical trade-wind profile during boreal winter, CMT acts as an apparent friction to decelerate the north-easterly flow. This effect maximizes below the cloud base while in the cloud layer, friction is very small, although present over a relatively deep layer. In the cloud layer, the zonal component of the momentum flux is counter-gradient and penetrates deeper than reported i

SUBMITTER: Dixit V 

PROVIDER: S-EPMC8244060 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature