Dust radiative feedback on Saharan boundary layer dynamics and dust mobilization

Abstract

Mineral dust radiative effectsand feedbacks upon Saharan boundary layer meteorology are estimated by means of regional dust simulations for a one-week period in May 2006. The regional dust modelsystem LM-MUSCAT is used, which allows online interaction of the computed dust load with the solar and thermal radiation and consequently with the model dynamics. For the Bodélé depression, a mechanism is proposed that describes positive and negative dust radiative feedbacks on surface wind speeds and dust emission in dependence on atmospheric stratification, dust-induced stabilization, and baroclinity. These effects are attributed to the formation and breakdown of the low-level jet (LLJ), which is a common phenomenon in the Bodélé. However, such processes are likely also relevant for other Saharan regions. Copyright 2008 by the American Geophysical Union.