INTERCOMPARISON OF NOCTURNAL LOWER-ATMOSPHERIC STRUCTURE OBSERVED WITH LIDAR AND SODAR TECHNIQUES AT PUNE, INDIA

Coordinated experiments to study the nocturnal lower atmosphere were c onducted on selected nights during April-August 1991 using an argon io n lidar and a Doppler sodar at the Indian Institute of Tropical Meteor ology, Pune (18 degrees 32'N, 73 degrees 51'E, 559 m MSL), India. The lidar and the sodar have been operated simultaneously so as to detect the nocturnal atmospheric structure in the common air volume sampled b y both the techniques. By analyzing the thermal and aerosol structures in the vertical profiles of the sodar and the lidar signal intensity, the nocturnal mixed-layer height or ground-based inversion height and the stably stratified or multiple elevated layers aloft have been det ermined. The top of the nocturnal ground-based inversion observed in t he sodar records is taken as the height above the ground where the neg ative vertical gradient in aerosol concentration first reaches a maxim um in the lidar records. The results of the study indicate an agreemen t between the lidar-derived mixing depth and the sodar-derived heights of the ground-based inversion and the low-level wind maximum.