Gravity waves generation around the polar vortex in the stratosphere
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Kaoru Sato
Department of Earth and Planetary Science, Graduate School of Science, The 
University of Tokyo
Email: kaoru@eps.s.u-tokyo.ac.jp
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It is considered that gravity waves are excited mostly in the troposphere. 
However, results of a hodograph analysis for small vertical-scale wind and 
temperature fluctuations observed in the polar stratosphere by radiosondes 
indicate that several tens percent of gravity waves propagate energy 
downward. This means that there exist gravity wave sources in the polar 
winter stratosphere (Yoshiki and Sato, 1999).
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We made intensive radiosonde observations with time intervals of 3 hours 
over ten days of each season at Syowa Station in the Antarctic in 2002. 
Moreover, we performed a simulation using an aqua-planet model with 
sufficient high resolution to resolve gravity waves explicitly. Through the
 
analysis of these observation and model data in detail, the mechanism of 
gravity wave generation around the polar vortex in the stratosphere is 
discussed.