Anatomy of a Severe Dust Storm in the Middle East: Impacts on Aerosol Optical Properties and Radiation Budget

Abstract

Particulate matter levels in large urban environments of the Middle East are affected by both anthropogenic and natural sources including frequent dust events which result in considerably enhanced aerosol concentrations with significant human health concerns. In this work, an integrated analysis is conducted of one of the most severe dust storms of the last 20 years in the Middle East. Using WRF-Chem simulations along with satellite data, particulate matter surface measurements and AERONET observations, we study the impact of this event on optical properties and surface radiation. At the peak of the dust storm in Doha, Qatar, both the surface data and the model predictions showed PM₁₀ concentrations in excess of 7,000 µg m^–3. A 2-week simulation over the whole peninsula revealed the extent of the event and showed that the model was able to capture the temporal and spatial evolution of the dust storm and the associated variations in aerosol optical properties. The simulations and remotely sensed measurements showed good correlation for the aerosol optical depth parameter, which reached a value of 3.0 on 2 April 2015 in the region. In agreement with satellite-derived estimates, the model predicted a significant storm-induced reduction in the shortwave radiation (150 to 300 W m^–2) reaching the eastern Arabian Peninsula, and the Gulf waters, and a considerable drop in the precipitable water (by a factor of 6) between 01 and 03 of April 2015. The domain-integrated maximum daily dust deposition rate that the model predicted was 27.5 Tg day^–1 mostly over the eastern part of Arabian Peninsula. The performance of the model is encouraging for further use in operational forecasting of dust storms in the region.