Continuous observations of NO2 and O-3 total columns at Terra Nova Bay station (Antarctica)

During the last few years UV-VIS spectrometers were developed at the ISAO Institute and are used for application of Differential Optical Absorption Spectroscopy (DOAS) methodology to detect some stratospheric trace gases playing an important role in pi,lar atmospheric chemistry, such as NO2, O-3, OCIO, BrO (Crutzen, 1970: Johnston, 1971; Johnston and Podolske, 1978; Brasseur and Solomon, 1984). After several tests both in the laboratory and in the Antarctic region, one of the spectrometers, called GASCOD 3/3, was modified for unattended and continuous measurement in extreme high-latitude environment. The instrument was installed in December 1995 at the Italian Station at Terra Nova Bay (TNB). The GASCOD is still working to study the denitrification processes during the formation of the so-called ozone hole over the Antarctic region. The results of nitrogen dioxide measurement are presented and discussed.