Optical exploration of biomass burning aerosols over a high-altitude station by combining ground-based and satellite data

Biomass burning activity captured the attention of the scientific community because of its significant impact on global climate change. In this paper, we present the results of a study of variations in aerosol optical, microphysical and radiative properties during biomass burning at an high-altitude rural station, Sinhagad (18°21U+05F3N, 73°45U+05F3E, 1450m AMSL), employing ground-based observations of MICROTOPS-II and short-wave (SW) Pyranometer, as well as satellite (MODIS) measurements of AOD during 28 April 2011-06 May 2011. Vertically resolved feature mask images from CALIPSO during night-time on available days are utilized as an additional tool to monitor the smoke/dust vertical distributions. A prominent smoke/dust layer is observed between 2 and 4km altitude, whereas the CALIPSO observations of the vertical profile of aerosols are in qualitative agreement with the values of MODIS-AOD550nm. During the smoke/dust event, a drastic increase (~0.9) in Terra/Aqua MODIS AOD550nm is observed. Satellite data indicate a long-range transport of aerosol particles from Indo-Gangetic Plains (IGP) over large regions. The observed short-wave solar flux at the bottom of the atmosphere (BOA) is found to decrease due to aerosol extinction and was found to be -25 and -16Wm-2 for the aerosol-laden days and normal days, respectively. In addition, the transport of a widespread forest fire plume is observed across the country as evidenced by the MODIS imagery and HYSPLIT back trajectories. The observed features are also explained on the basis of the results from the NCEP/NCAR and ECMWF re-analysis data