Long-range transport of dust aerosols over the Arabian Sea and Indian region — A case study using satellite data and ground-based measurements

The present study addresses an intense dust storm event over the Persian Gulf and the Arabian Sea (AS) region and its transport over the Indian subcontinent using multi-satellite observations and ground-based measurements. A time series of Indian geostationary satellite KALPANA-1 Very High Resolution Radiometer (VHRR) together with ground observations are used to analyze the temporal variation of the dust event that occurred from 19 to 24 February 2008 with the strongest intensity on 22 February. The Ozone Monitoring Instrument (OMI) Aerosol Index (AI) is also examined to provide an independent assessment of dust presence and plume location. During the dust event drastic increase in Terra/Aqua MODIS AOD550 (> 1.0) and AURA-OMI-AI is observed. Vertically-resolved attenuated backscatter during daytime and nighttime from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) is also used as an additional tool to monitor the dust vertical distribution. The main dust layer is observed to be situated between 3 and 5 km in altitude, while the CALIPSO observations on vertical profile of aerosols are in qualitative agreement with values of MODIS-AOD550 and OMI-AI. Ground-based measurements show significant reduction in solar irradiance on the dust-laden day (22 February 2008) over Hyderabad, while sun photometer derived AODs from six AERONET sites in south Asia verify the presence of dust and its transport from west to east.