Investigating WRF-Chem Dust Emission Performance During an Extreme Dust Storm in India

Airborne dust is an essential component of climatological and biogeochemical processes. Blowing dust can also adversely affect agriculture, transportation, air quality, sensor performance, and human health. As a result, the accurate characterization and forecasting of dust events is a priority for air quality researchers and operational weather centers. In mid-June 2018, a major multi-day dust storm originating in the Thar Desert struck the Indo-Gangetic Plain and its many major population centers. This event lasted six days and brought visibilities down to half a kilometer at times in multiple cities, creating dangerous conditions and poor air quality. This storm occurred during a particularly dusty pre-monsoonal season and was driven by a strong thermal surface low that developed along the Indian/Pakistani border. We used WRF-Chem version 4.6.0 to examine the evolution of the dust event with MERRA-2 reanalysis to provide initial and boundary conditions for the aerosol and chemical fields. We tested the five currently available dust emission and transport module configurations and examined their performance relative to surface observations and remotely sensed data for this extreme case.

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