Assembling a High Energy Pulse Lidar (HEPL) System: Preliminary Results from an Astronomical Site in the Central Himalayan Region

An indigenously designed High Energy Pulse LIDAR (HEPL) system was re-integrated and installed at ARIES, Nainital, for probing the atmosphere and to analyse the Mie scatterers. After the characterization of the Photomultiplier tube and Discriminator, about 50 quality checked valid measurements were investigated. Reasonably good signals were obtained upto ~2.5 km for 30 m altitude resolution, ~5 km for 150 m, and ~8 km for 300 m resolutions in the vertical, which were utilized to investigate the aerosol and cloud profiles. The system was able to capture the clouds at various altitudes under different atmospheric conditions. Elevated aerosol layers were also detected at about 3 and 3.5 km over the observation site. Such unique measurements from the data void complex Himalayan terrain highlight the need for continuous monitoring of the aerosol loading caused by transport of pollutants from continental locations and far-off distances that affect the air quality and Himalayan glaciers as well.