NISHI Noriyuki Kyoto University, Department of Geophysics, Research Associate, 大学院・理学研究科, 助手 (00222183)
HASEBE Fumio Hokkaido University, Graduate School of Environmental Earth Science, Professor, 大学院・地球環境科学研究科, 教授 (00261735)
YAMAZAKI Koji Hokkaido University, Graduate School of Environmental Earth Science, Professor, 大学院・地球環境科学研究科, 教授 (70270791)
This research program was intended to investigate the stratosphere-troposphere exchange processes based on complementary use of the global and station data, and numerical model output. Special attention was paid to the ozone and water vapor distributions in the tropical tropopause region where dynamical, radiative and chemical interactions of these minor species on the climate is crucial. In addition, we have performed 18 campaign observations of ozone and water vapor sondes in the eastern, central and western Pacific to fill the gap of data sparse regions around the equator. At the same time we had been testing and improving a commercial chilled-mirror hygrometer, so called "Snow White", in collaboration with foreign investigators. The main part of our research activity is summarized in the following.
1) Our water vapor sonde observations first revealed the seasonally and locality of water vapor profiles in the tropical tropopause region (Voemel et al., 2002).
2) It is suggested using water vapor observations in the eastern Pacific that the equatorial Kelvin wave may control a water vapor entry value into the stratosphere (Fujiwara et al., 2001).
3) On the basis of the global analysis data and general circulation model output the ENSO-related signals in temperature and upward velocity in the equatorial tropopause were detected and discussed (Hatsushika and Yamazaki, 2001).
4) We have conducted ozonesonde observations on board the research vessel "Shoyo-Maru" and found several characteristic features in the equatorial eastern Pacific (Shiotani et al., 2002).
5) We have made several intercomparison campaigns with other water vapor sensors and evaluated their performance (Fujiwara et al., 2003 ; Voemel et al., 2003).