An integrated analysis of lidar observations in association with optical properties of aerosols from a high altitude location in central Himalayas

Abstract

In order to study the aerosol backscatter profiles, a portable micro pulse lidar (MPL) system was installed in the year 2006 at Manora Peak, (29◦ 22 N, 79◦ 27 E, ∼1960 m amsl) Nainital, a high altitude location in the central Himalayas. In the present study the results of observed lidar profiles, columnar aerosol optical depths (AOD) and prevailing meteorology during May 2006 to June 2007 are presented. Although the lidar was operated from a sparsely inhabited free tropospheric site, nevertheless the height distribution of aerosol layers are found to be extended up to the summit of ∼2 km above the ground level (AGL). The backscatter ratio (BSR) varies from ∼10 to ∼20 having lowest values during post-monsoon and highest during pre-monsoon period. The observed boundary layer height during the post monsoon was shallower to the pre-monsoon period. Occasionally the lidar profiles reveal the presence of cirrus clouds at an altitude of 8–10 km AGL. The extended lidar observations over Manora Peak not only provided the profiles of aerosol extinction coefficient but also significantly substantiate the elevated aerosol layers and clouds, which are important in the study of climate modelling.