Some results of lidar aerosol measurements and their relationship with meteorological parameters

Vertical profile measurements of aerosol number density remotely in the lower atmosphere during night-time using a bistatic, continuous wave Argon ion laser radar (lidar) system have been in progress at the Indian Institute of Tropical Meteorology, Pune, India since September 1986. The observational programme includes the measurement of a minimum two and maximum seven vertical profiles of atmospheric aerosols in each month. This paper deals with the results of the analysis of lidar aerosol data archived for a period of one year (October 1986–September 1987) and presents the monthly variations in the height distribution of aerosol number density along with their deviations from the annual mean distribution. Also, presented in this paper are the results of (i) the temporal changes in the aerosol concentration at 30 m AGL and its relationship with surface wind and relative humidity, and (ii) the comparison of the aerosol profiles on some selected days with the near-simultaneously obtained vertical profiles of wind, temperature and relative humidity. The results suggest that variations of aerosol concentration exhibit a certain relationship with those of meteorological parameters, and the atmospheric stability conditions associate with the vertical gradients of concentration at the top of the aerosol layer.