Development of a physically based dust emission module within the Weather Research and Forecasting (WRF) model: Assessment of dust emission parameterizations and input parameters for source regions in Central and East Asia

Significant problems with modeling dust emission are highlighted. Not only do dust emission schemes rely on various assumptions, but also their implementation within a regional or global model presents challenges. This paper provides an in-depth comparative analysis of two different physically based schemes that were originally developed by Marticorena and Bergametti (1995) and Shao et al. (1996) with some recent improvements. Both schemes were implemented in a dust module (DuMo) and coupled with the Weather Research and Forecasting (WRF) model. Here we examine the physical parameterizations employed by these schemes, identify the key input parameters, and establish linkages between them by developing a new data set for dust sources in Central and East Asia. The relative importance of the input parameters is assessed through partial derivatives. The major issues involved in implementing the physically based schemes within a regional model are also discussed. Consistent implementation of two state-of-the-art dust schemes within the same regional model enables us to bracket inherent uncertainties in simulated dust emission. The results of a case study based on WRF-DuMo simulations are presented to demonstrate associated biases in the magnitude and spatial patterns of emitted dust vertical fluxes. Also, recommendations on the selection of input parameters, including land and meteorological variables, to achieve an improved modeling of dust emission in Central and East Asia are provided.