Publications

Sharma, D; Kulshrestha, U (2017). Dust storms and their influence on optical and chemical properties of aerosols along north-western Indo-Gangetic Plains. JOURNAL OF INDIAN GEOPHYSICAL UNION, 21(6), 526-534.

Abstract
Dust storms are an important climatic phenomenon in the Indian subcontinent affecting air quality in the pre monsoon season. In this study, the variation in the optical and the chemical properties of mineral dust aerosols along the north-western Indo Gangetic Plains (IGP) is recorded during major dust storm events during April to June, 2015. Dustfall fluxes were measured at five sites lying on the downwind trajectory of the long-transported dust plume. The sites were -Bikaner (BK), Jaipur (JP), Hisar (HS), Delhi (DL) and Agra (AG). Five major dust storm events were identified based on the aerosol optical depth (AOD) values derived from the MODIS and OMI instruments and corroborated by the ground monitored dust fall flux measurements. An analysis of the optical properties reveals the dominance of coarse mode particles during all the events with MODIS Angstrom Exponent (AE) values lying in the range of 0.40-0.03 for dust events observed at the sites located in the close proximity of Thar desert. Chemical characterization of the samples showed that Ca2+ was the most dominating cation with flux in the range of 106.7 mg/m(2)/day (at BK) to 7.4 mg/m(2)/day (at DL), indicating the dominance of crustal sources in the dust aerosols. Among anions, highest flux was recorded for SO42- and NO3-. NO3- flux was observed to increase downwind towards the sites (DL and HS) with high anthropogenic emissions. The flux Na+ and Cl- was also high during major dust events. However, it was seen to decrease downwind indicating the influence of sea salt fraction in the dust plume transported from the Arabian sea.

DOI:

ISSN:
0257-7968