Transport of a severe dust storm from Middle East to Indian region and its impact on surrounding environment

The present work focuses on the long-range transport of dust particles emanated after a severe dust storm hit the Middle East during 18–22 March 2012. The effect of dust-induced aerosol particles on short- and long-wave radiation over the region and positive feedback on oceanic primary productivity have been investigated. For this purpose, we have carried out simulations of dust storm using WRF-Chem and evaluated the results with respect to the in situ and remotely sensed observations using descriptive statistical analysis. It is noted that the dust transport pathway has been nicely captured by the WRF-Chem model. Model simulated higher aerosol optical depth (AOD) values (> 2.0) are found over a large part of North and North-western India on 20 March 2012. A considerable drop of 50 W m−2 in short-wave radiation was noticed over the Northern India region due to the considerably high dust loading in the atmosphere. Model simulated AOD revealed significant correlation (at 99% confidence interval) with the AERONET observations (r = 0.92 for Meziara, r = 0.85 for KAUST campus and r = 0.62 for Jaipur stations) along the dust transport path. Substantial decrease in sea surface temperature from 20 to 7 °C is noted over the Arabian Sea during dusty days. A significant increase in the chlorophyll-a concentration from 4 to 14 mg/m3 is also observed with a time lag of 4 days subsequent to the increase in AOD over the central Arabian Sea. Results obtained here indicate a positive feedback mechanism of dust deposition on enhanced primary productivity.