Venus boundary layer dynamics: eolian transport and convective vortex

TL;DR

This study uses a turbulent-resolving model to analyze Venus's boundary layer dynamics, revealing diurnal cycles, convective vortices, and surface wind effects on dust lifting and dune formation for the first time.

Contribution

First application of a turbulent-resolving model to Venus's boundary layer, demonstrating diurnal effects, convective vortices, and surface wind impacts on surface features.

Findings

Diurnal cycle causes convective layers up to 7 km high.

Surface winds at noon can lift dust particles.

Convective vortices are observed for the first time on Venus.

Abstract

Few spacecraft have studied the dynamics of Venus' deep atmosphere, which is needed to understand the interactions between the surface and atmosphere. Recent global simulations suggest a strong effect of the diurnal cycle of surface winds on the depth of the planetary boundary layer. We propose to use a turbulent-resolving model to characterize the Venus boundary layer and the impact of surface winds for the first time. Simulations were performed in the low plain and high terrain at the Equator and noon and midnight. A strong diurnal cycle is resolved in the high terrain, with a convective layer reaching 7 km above the local surface and vertical wind of 1.3 m/s. The boundary layer depth in the low plain is consistent with the observed wavelength of the dune fields. At noon, the resolved surface wind field for both locations is strong enough to lift dust particles and engender micro-dunes. Convective vortices are resolved for the first time on Venus.