HR: 1340h
AN: A33A-0875    [Abstracts]
TI: Effect of Pre-monsoon Dust Storms During 2001 - 2005 on the Aerosol Properties Over the Indo-Gangetic Basin
AU: * Prasad, A K
EM: akprasad@iitk.ac.in
AF: Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur, UP 208016 India
AU: Chauhan, S S
EM: sssc@iitk.ac.in
AF: Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur, UP 208016 India
AU: Singh, R P
EM: ramesh@iitk.ac.in
AF: Department of Civil Engineering, Indian Institute of Technology Kanpur, Kanpur, UP 208016 India
AU: Holben, B
EM: bholben@pop900.gsfc.nasa.gov
AF: NASA Goddard Space Flight Center, (GSFC), Greenbelt, MD 20771 United States
AB: The Indo-Gangetic (IG) basin is characterized by the higher aerosol optical depth (AOD) (>0.4) throughout the year. During summer season (pre-monsoon season), aerosol loading is found to be maximum and over same period a number of dust events have been observed. Significant increase in AOD during summer season has been observed over the IG basin using Moderate Resolution Imaging Spectroradiometer (MODIS) data. Here, we present detailed characterization of aerosol parameters during dust storms (summer season, 2001-2005). We have used ground (Kanpur AERONET, Central Pollution Control Board) and multi-sensor and multi-level data from MODIS, National Centers for Environmental Prediction/ Climate Prediction Center (NCEP/CPC) infra-red (IR) data to characterize dust storms in terms of aerosol optical depth (AOD), angstrom exponent, single scattering albedo (SSA), aerosol size distribution (ASD), real and imaginary parts of the refractive index (RI) and brightness temperature (spatial extent). During summer season, a diurnal variation of 0.1-0.2 in AOD is found primarily due to local dust originating from vast fallow agricultural fields in the IG basin. A radical change is observed in aerosol parameters associated with dust storms based on AERONET and MODIS data. AOD values becomes very high (>0.9 with high standard deviation) with maximum value of ASD in the range 1-8 microm. Variations in SSA and RI clearly show dust and non-dust events. Spectral characteristics of AOD provide information about the dust events associated with desert areas. Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) transport and dispersion model have been used to trace origin and path of each of these major dust events (5 days back-trajectory). Hourly NCEP/CPC IR (2005) and daily or eight days MODIS overpass data have been used to trace total area affected by dust storms along its path and spatial characteristics of dust tracked since beginning of event from the western side and its arrival in Kanpur, an industrial city of the IG basin. The impact of dust storms on the radiative forcing will be discussed in the present paper.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0368 Troposphere: constituent transport and chemistry
DE: 1610 Atmosphere (0315, 0325)
DE: 3322 Land/atmosphere interactions (1218, 1631, 1843)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005