Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5431062 | Journal of Quantitative Spectroscopy and Radiative Transfer | 2006 | 9 Pages |
Aerosols affect the radiative energy budget on both the regional and global scales. The wavelength-dependent aerosol optical depth (AOD) is a fundamental determinant of the amount by which extra-terrestrial incoming sunlight and outgoing terrestrial radiation are being attenuated in the atmosphere. The present study addresses the influence of local waste burning on aerosol characteristics, black carbon (BC) aerosol mass concentration and spectral solar irradiance using ground-based measurements over the tropical urban environment of Hyderabad, India. AOD has been observed to be maximum during burning days compared to normal days. Aerosol size spectra suggest bimodal distributions during pre-and post-burning periods and trimodal distributions during burning periods. Angstrom wavelength exponent estimated from spectral variation of AOD suggested dominance of accumulation mode particle loading during burning days compared to normal days. Diurnal variation of BC on normal days showed a broad nocturnal peak during â¼20:00 to â¼24:00 h with a maximum value of BC aerosol concentration of â¼14,000 ng mâ3 whereas on local waste burning days enormous increases in BC concentrations have been observed with a peak at â¼60,000 ng mâ3. Relative attenuation of global solar irradiance during burning days has been found to be of the order of 30% in the visible and 28% in the near-infrared regions. The results are discussed in detail in this paper.