Low-latitude total ozone measurements in the Brazilian sector

Regular measurements of the atmospheric ozone in the Brazilian sector were started at Cachoeira Paulista (22.7°S, 45.0°W), and Natal (5.8°S, 35.2°W) in May 1974 and November 1978, respectively. The results of the total ozone measurements carried out at these two stations up to 1981 are presented in this communication and compared with other low-and mid-latitude stations. Although Natal is an equatorial station, it presents a prominent annual variation, and the average total ozone content is high compared to satellite measurements. During 1977–78, abnormally low values of total ozone were observed at Cachoeira Paulista. Some preliminary results about the QBO 9quasi-biennial oscillation) during 1974–81 are also presented.