Five Years Of Total Ozone Measurements At Belgrano2 Antarctic Station

The survey of stratospheric Ozone in Antarctica by PNRA (National Research Program in Antarctica) of Italy had a start in 1988-1989 at New Zealand Scott base (discontinued in1996), then on January 1992 a second Brewer was installed in the antarctic Argentine base Belgrano 2 (77° 52' S, 34° 38' W) in the southermost tip of the Weddel sea. The station, managed by the Argentine Antarctic Program, is situated on the nunatak Bertraub at about 10 nautical miles from the coast at an elevation of 255 metres from sea level. The operator, who is in charge of the Brewer program, usually has previous training on an identical instrument which is in operation at the Ushuaia (Tierra del Fuego) station. The climatic conditions of the site are rather severe, with temperatures during the winter that stay below -20°C for long periods of time. Winds also affect the instrument and it's use, in particular, frequent catabatic episodes due to the presence of the Antarctic plateau, south of the site. Finally, the lack of direct sunlight during the period of March to September is a limitation. During that time interval it is preferred to bring the instrument inside the laboratory because the amount of effort to obtain few Zenith Sky or Moon measurements does not compensate for the risk due to the adverse climatic conditions. The behaviour of total ozone and some statistics for the years 1992 to 1997, with the exception of 1994 (when the ship could not get to the station) will be presented together with some comparison with complementary data taken at the Marambio (Argentine Meteorological Service ) and Halley Bay (UK British Antarctic Survey) stations, where two Dobson are in service. Finally some Brewer-Umkehr profiles of Belgrano station will be shown providing evidence of the Ozone Hole phenomenon.