Dust storm analysis in Northern China during the March 2002 episode

Dust storm formation is closely related with local and large-scale climate variability and anomalies. The mineral dust aerosol injected into the atmosphere may modify the direct radiative forcing, the cloud evolution and dynamics, the marine biochemistry, the air quality with consequence on human health and visibility. Large amount of mineral dust, originating from the desert regions in East Asia, is annually transported to the Asian continent and Pacific Ocean. In these regions, dust storms occur usually in Spring, in the extensive area between 110 and 117 degrees east, around 38 degrees north. Numerical models are of primary importance in the description of the processes of emission, transport and deposition of dust from desert zone, reconstructing the dust spatial and temporal distributions. For this aim, a model-chain is developed and applied to the case study of March 2002, when an intense dust storm affects Beijing and surrounding regions. This model-chain is based on three different modules: RAMS model provides the input meteorological data for the other modules; DUSTEM model, specifically developed for this aim, simulates the dust emission from the desert; CAMx model takes the meteorological inputs from RAMS and the emission rate from DUSTEM, providing the dynamical transport and deposition of the dust particles. Numerical results are compared to in-situ measurements obtained from other studies on this important dust storm episode, in order to evaluate the effectiveness of the model-chain.