Studies on Lower Tropospheric Aerosols over New Delhi,India Using Lidar

This study reports the altitude distribution of physical and optical properties of aerosols in the lower troposphere over the urban tropical region Delhi measured using an UV (355 nm) lidar which is capable of operating in both day and night time. It is observed that there is strong seasonal variation in the altitude (from 0.4 to 4 km) distribution of aerosols during the observation period from July 2009 to May 2010. The aerosol extinction coefficient and depolarization values range from 0.02 to 0.6 km^?1 and 0.02 to 0.05 respectively during the observation period. Relatively high aerosol extinction coefficient values were observed below 1.5 km altitude during the autumn season may be due the festivals and bio-mass burning activities. In all the seasons except winter, the aerosol loading from 0.4 km to 4 km range contributes more than 38% to the atmospheric column optical depth.