MILLIMETER-WAVE MEASUREMENTS OF CHLORINE MONOXIDE AT THE JUNGFRAUJOCHALPINE STATION

During the European Arctic Stratospheric Ozone Experiment (EASOE) in w inter 91/92, first measurements with a new 204GHz radiometer were perf ormed at the Jungfraujoch Alpine Station (7-degrees 59'E 46-degrees 33 'N) in the Swiss Alps. The altitude of this site (3570m) allows detect ion of weak spectral lines like the ones of the chlorine monoxide J 11 /2-->9/2 rotational transition. At the end of January 1992, a large am ount of ClO in the lower stratosphere was measured, indicting that hig hly airmasses had been transported towards mid latitudes. The maximum value of the ClO volume mixing ratio was about 1ppbv +/- 0.4 ppbv in h eights of 15-25km.