During the EASOE campaign ground-based FTIR measurements have been performed in March 1992 at Ny-¿lesund (Spitsbergen, 79¿N, 12¿E) to derive column amounts of several trace gases. For the first part of the measurement campaign Ny-¿lesund was situated inside the polar vortex.

The obtained concentrations of N2O, CH4, and HF inside the vortex are consistent with subsidence. The ratio of HClstrat/HF varied from about 2.0 inside to about 2.8 outside the vortex. Inside the vortex low values for NO2 and high values for HNO3 were found. The O3 concentrations inside the vortex are slightly lower than what was observed outside the vortex. ¿ American Geophysical Union 1994