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 (782KB)
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186,576,000 Yen (FY1998; 63,492,000 Yen)
Temperature lower than PSCs threshold was observed in the Arctic polar vortices in three winter seasons since 1995. In order to clarify the effects of the ozone depletion in the Arctic polar vortex on the mid-latitude region, we carried out following observation and analyses: Ozone sonde measurements at Yakutsk in Eastern Siberia in Russia and at Moshiri in Hokkaido Island in Japan, visible spectrometer measurements at Moshiri and Rikubetsu in Hokkaido Island, FTIR measurements at Moshiri and Rikubetsu, millimeter radiometer measurements of ozone at Rikubetsu and Tsukuba, lidar measurements at Rikubetsu. The observed data are analyzed together with meteorological data such as ECMWF. Intensive observations were carried out based on the Arctic vortex information or "MATCH" information based on the ECMWF data in the framework of European Ozone Projects such as SESAME and THESEO. Especially, in the case of April 1996 campaign in Hokkaido, we predicted the polar vortex events over Hokkaido and carried out intensive ozone sonde and FTIR measurements. The estimated ozone depletion in the vortex air was approximately 60 % comparing with the similar case observed in 1972. The FTIR data also gave evidences of the effects of the heterogeneous process on PSCs in the Arctic polar vortex. These results were consistent with the estimation given by the MATCH result. Such phenomena were also observed in May 1997. The degree of ozone depletion was consistent with the MATCH results, the ozone depletion estimated based on the Yakutsk ozone sonde and the ILAS MATCH. As this result indicates the importance of more frequent and more comprehensive measurements of parameters and species in the stratosphere, we developed a millimeter radiometer and temperature laser radar to be installed at Rikubetsu.
Ozone depletion in the northern high- and mid-latitude, polar vortex, PSCs, vorticity analysis, FTIR, millimeter radiometer, laser radar, ozone sonde