IN-SITU MEASUREMENTS OF NITRIC-OXIDE, OZONE, AND AEROSOLS IN THE SCANDINAVIAN ARCTIC STRATOSPHERE IN JANUARY 1992

During the European Arctic Stratospheric Ozone Experiment (EASOE) the Arctic stratosphere was investigated with a set of instruments flown o n a CNES high altitude balloon from ESRANGE, northern Sweden (67-degre es 52'N, 21-degrees 4'E) on January 22, 1992. The vertical profiles to an altitude of 30 km are presented for ozone, nitric oxide, aerosols, and the temperature. The ozone mixing ratio was less than 0.1 ppmv be low 13km, and increased significantly only above the 18.5 km level. Th e aerosol concentration profile shows a large peak between 13 km and 2 1km, centered at 18.5 km, reaching as high as about 10 particles/cm3. Above 24 km the aerosols were absent. Below 22 km, the NO mixing ratio was lower than 50 pptv; however it increased rapidly from 23 km with a sharp peak at 27 km. The rapid increase in NO occurs just at the alt itude where the aerosol concentration falls below the detection limit : on this day, NO was present only in the absence of aerosols.