This research is focused on using a newly developed balloon borne sensor for evaluating the long term global atmospheric effects of the recent Mt. Pinatubo volcanic eruption, especially in regard to its influence on global and polar ozone depletion, global optical depth changes, atmospheric temperature variations, and the possible influence on global tropospheric aerosols. The research will also help characterize the global volcanic cloud so that it can be put in proper perspective for comparison with past volcanic eruptions. Systematic balloon sounding of aerosol and ozone will be made at a mid-latitude station in both the northern and southern hemisphere where other supporting measurements are also being made. As an additional opportunity, variations of tropospheric aerosols and ozone will also be systematically investigated. It is believed that such variations can be traced to biomass burning episodes and are highly significant in regard to tropospheric chemistry on a world scale.