Importance of the Numerical Representation of Shallow and Deep Convection for Simulations of Dust Transport over a Desert Region

Abstract

This study examines the representations of shallow and deep convection under two distinct stability conditions over a desert region with the use of the numerical outputs from large-eddy simulations at the 100 m horizontal resolution. The numerical experiments were set up under idealized conditions of a horizontally uniform basic state over a homogeneous and flat surface, which was aimed at representing fair-weather convective situations over the Gobi Desert. Spatial spectra were used in order to examine how small scales are reproduced and how representative scales appear at various heights. From the results of the spectral analyses, a grid scale required to properly represent shallow and deep convection in convection-resolving simulations is identified. It is indicated that the adequate representations of shallow and deep convection are critically important in simulating the transport of dust aerosols under convective conditions.