Results on aerosol measurements from balloons

Abstract

A balloon-borne sun-tracking spectroradiometer was designed and developed at the Physical Research Laboratory, Ahmedabad, to make measurements of the direct solar radiation and the angular distribution of the scattered radiation intensities at tropospheric and stratospheric altitude levels. Measurements are made at six different wavelength bands from UV to IR region so as to obtain information on the vertical distribution of aerosol concentration and the size distribution function. The experiments are realized under the Indian Middle Atmosphere Programme. Results of the four successful measurements made since 1984 are presented. Results on aerosol number density and size distribution, first of its kind over the Indian subcontinent, reveal many interesting features such as altitude variation of aerosol size distribution parameter and their dependence on volcanic eruptions at stratospheric altitudes, and variations in aerosol number densities at tropospheric altitudes before and after the Indian monsoon.