Association of aerosol optical depth with near surface aerosol properties in urban environment

Abstract

Changes of near surface aerosol properties and their association with aerosol optical depth studied over tropical urban environment in Hyderabad during January-May, 2003 corresponding to winter and summer seasons have been presented. Aerosol Optical Depth (AOD) has been studied using MICROTOPS-II sunphotometer and aerosol size distribution has been studied using Quartz Crystal Microbalance Particle analyzer. Results from the study suggest that the temporal variation of near surface sub-micron aerosol mass concentration and columnar aerosol optical depth at 500 nm are well correlated. Aerosol size index as well as Angstrom wavelength exponent has been found to be high during February, indicating relative dominance accumulation mode particles. During summer season Angstrom exponent values have been found to be low indicating relative dominance of coarse mode particles.