A Study of Chemical Processes Leading to Ozone Losses in the Midlatitude Stratosphere

点击翻译按钮获取中文摘要

Vertical column amounts of the stratospheric trace species have been observed using a Fourier transform spectrometer at Rikubetsu (43.5ﾟN,143.8ﾟE), Hokkaido, Japan since July, 1995. The spectrometer used is Bruker 120 M with the highest spectral resolution of 0.0035 cm^<-1>. Solar spectra between 500 and 4400 cm^<-1> have been measured to derive column amounts of HCl, HF,ClONO_2, and O_3 in the stratosphere.Long term O_3 decrease observed in Japan is the largest in Sapporo (43ﾟN). In addition, the O_3 changes associated with the Pinatubo eruption was much larger in Sapporo than at lower latitudes [Kondo et al., 1995]. Occasionally, air masses inside the vortex are transported over Rikubetsu in spring. Because the latitude of Rikubetsu is close to Sapporo, measurements of these species will give us an improved understanding the mechanism of the large O_3 changes observed at 43ﾟN.The temporal variations of HCl and HF vertical column amounts have been observed since July 1995. Both species show seasonal variation increasing from autumn to winter. It has been found that the day-to-day variations of these two species are well correlated. Changes in the tropopause height are also well correlated with the changes of these species. We plan to obtain column amounts of HCl, HF,ClONO_2 and O_3 observed during a whole year period and make analysis of these values in terms of chemical and transport processes.Reference : Kondo et al., Stratospheric ozone changes at 43ﾟN and 36ﾟN over Japan between 1991 and 1994, Geophys. Res.Lett, 22,3223-3226,1995.