The Radiative Effect of Dust on the Convective Boundary Layer of Mars

Abstract

Mars has an abundant amount of dust in its atmosphere that can have significant effects on the structure and dynamics of the Convective Boundary Layer (CBL). In this study, we employ a Large Eddy Simulation (LES) configuration of the Mars Weather Research and Forecasting (MarsWRF) model to investigate the radiative effects of dust on the Martian CBL. Our results reveal that while dust reduces the amount of solar radiation reaching the ground surface, it also absorbs and re-emits the radiation energy, leading to a warming effect in the CBL. We find that the increase in dust concentration may enhance turbulence near the top of the CBL while suppressing mixing in the lower layers. This process leads to the development of a deep but stable and stratified boundary layer, which turns out to affect the transport and distribution of dust. In addition, our results indicate that evaluating the boundary layer depth with the bulk Richardson number could be inappropriate in dusty conditions. The radiative heating of dust may reduce the vertical gradient in the Richardson number, so it is less effective to determine the true boundary layer height with the conventional threshold-based methods.