MID-LATITUDE SUMMERTIME MEASUREMENTS OF STRATOSPHERIC NO2

The vertical distribution of stratospheric nitrogen dioxide was measured during the Atmospheric Environment Service STRATOPROBE projects in August of 1975 and 1976. Vertical profiles of NO//2 are determined by measuring the NO//2 adsorption of sunlight from a balloon platform during sunrise and sunset and inverting the absorption curves. A total of four sunrise/sunset pairs of observations were obtained from balloon flights of August 10 and 17, 1975 and Aug 19 and 28, 1976. The measurements show significant stability of the NO//2 profile from flight to flight with variations of less than 15% between individual profiles. The average NO//2 concentration at sunset was found to increase from about 0. 3 ppbv at 10 km to 10 ppbv at 35 km. At sunrise the concentrations increase form 0. 2 ppbv at 10 km to 5 ppbv at 35 km.