[A-AS10] 成層圏・対流圏 (大気圏) 過程とその気候への影響

[AAS10-P05] スーパープレッシャー気球とPANSYレーダーによる近慣性重力波の同時観測

*冨川 喜弘¹、村田 功²、高麗 正史³、佐藤 薫³ (1.国立極地研究所、2.東北大学、3.東京大学)

キーワード：慣性重力波、南極、スーパープレッシャー気球、PANSYレーダー

Simultaneous observations using a long-duration balloon and a large aperture atmospheric radar, PANSY, were performed at Syowa Station, Antarctica, from January to February 2022. They captured near-inertial gravity waves (NIGWs) in the lower stratosphere. The analysis using both datasets revealed that the NIGWs with an upward group velocity, a vertical wavelength of 2.4 km, and a ground-based period of about 10 hours propagated eastward above Syowa Station. Comparison with the latest reanalysis ERA5 showed that although the NIGWs over Syowa Station were qualitatively represented, their amplitudes were underestimated in ERA5. In addition, as the NIGWs propagated eastward, they were no longer captured even qualitatively by ERA5. This suggests that as the NIGWs propagated eastward, they approached the critical level and could no longer be represented by ERA5 because the vertical wavelengths became shorter. This result implies the difficulty to explicitly represent the behavior of NIGWs near the critical level even in the high-resolution simulation.