Laser radar study of the middle atmosphere over Ahmedabad

Abstract

An Nd: YAG backscatter lidar is built at the Physical Research Laboratory, Ahmedabad (23°N, 72.5°E) to study the vertical distribution of aerosols in the troposphere and stratosphere, and atmospheric density and temperature in the 30-50 km altitude region. The system is operational during nighttimes since April 1992. This paper presents the system details and analyses of different types of noises encountered in a lidar system. The applicability of the Klett algorithm in solving the lidar equation is discussed. Results on the Pinatubo volcanic aerosol layer and its decay observed over Ahmedabad are presented and discussed. With higher integration time vertical profiles of number density of air molecules and temperature profiles are obtained in the 30-50 km region which are compared with standard atmospheric models. The future augmentation of the system and planed activities are also outlined.