Modeling a severe wintertime Asian dust event observed in the East Asia region: Sensitivity of the WRF-Chem dust emission schemes

Abstract

This study investigates the capability of the Weather Research and Forecasting-Chemistry (WRF-Chem) model in modeling a severe wintertime Asian dust event, which originated from the East Asia dust source region during 20–22 February 2015. The WRF-Chem simulations were conducted changing with the five embedded dust emission schemes of the UC01, UC04, UC11, GO01, and GA19 schemes. The model reasonably simulated meteorological fields, capturing the characteristic meteorological features over the dust source regions during the severe wintertime Asian dust event. A good meteorological comparison led to the reasonable simulation of the occurrence and transport of the Asian dust plumes, comparing well with the surface dust occurrence reports and the satellite-detected dust signals of aerosol optical depth (AOD) and extinction coefficient. However, considerable (approximately fivefold) differences existed in the dust emission amounts simulated by the different dust emission schemes. From the model-measurement comparison of surface PM10 concentration, it was found that the UC01 and UC04 schemes could simulate the severe wintertime Asian dust plumes in the dust source regions, capturing the dust occurrence timing and the concentration level reasonably. However, the performance of the schemes significantly depended on near-surface wind speed and soil moisture amount. On the contrary, the UC11, GO01, and GA19 schemes failed to simulate the dust plumes, revealing intrinsic limitations for severe wintertime dust plume simulation. Furthermore, this study suggests the realistic representation of the Asian dust source region and the inclusion of frozen soil parameterization in the WRF-Chem model to predict severe wintertime Asian dust events realistically.