Preliminary Report on the Vertical Distribution of Aerosol Particles over the Nepal Himalayas

Glaciological Expedition of Nepal, Contribution No. 74

Abstract

Aircraft observation of aerosol particles was carried out for the first time in the atmosphere over the Nepal Himalayas on October 22, 1978. The sampling of aerosols was done at the ground (1320 m, al), 2000 m, 3000 m and 5600 m (asl) above Kathmandu, and 5600 m and 7800 m (asl) above Langtang Valley. Morphological studies of the collected particles by an electron microscope show that particles similar to the shape of sulfuric acid dominated above 5600 m, while ammonium sulfate particles dominated below 3000 m. On the basis of upper air sounding and cloud conditions, convective activities of the air can be considered to occur to the level of 5000 m corresponding to the change of aerosol types. Aerosols considered to be combustion products were superimposed at the ground in Kathmandu.