Preliminary Results of Two-day Consecutive Aircraft Observations in Typhoon Neoguri (2025)Satoki TSUJINO1, Kazuhisa TSUBOKI2, Sachie KANADA2, Soichiro HIRANO3, Takuya TAKAHASHI1, Munehiko YAMAGUCHI1, Masaya KATO2, Taro SHINODA2, Udai SHIMADA1, Yasuhiro KAWABATA1, and Akiyoshi WADA1
1: Meteorological Research Institute, Japan Meteorological Agency
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| The Meteorological Research Institute started a new field observation experiment with dropsondes from an aircraft for typhoons and atmospheric rivers from 2025. For the typhoon mission, we observed the inner core of Typhoon NEOGURI for two consecutive days during a period from the mature to the rapid weakening phases in collaboration with the T-PARCII project of Nagoya University. This presentation showed an overview of the observations and the preliminary results. On the first day in the mature stage, the well-developed low-level warm air with the strong temperature inversion layer at a height of 2 km was observed by dropsondes near the center, corresponding to the central pressure of 930 hPa near the sea surface. Moreover, the maximum tangential wind was found around 500 m altitude, suggesting a thin boundary layer. Near the maximum wind radius, a weak vertical shear of the tangential wind indicates an approximately equivalent barotropic vortex structure, while in the eye, a strong vertical shear of the tangential wind is observed in a layer of 2-3 km. The tangential wind shear in the eye is consistent with the low-level warm air through the thermal wind balance. The structure of the strong (weak) shear in the eye (eyewall) suggests a potential-vorticity bridge. On the second day in the rapid-weakening stage, the profile of equivalent potential temperature near the eye was similar to that at the radius of the maximum wind speed, suggesting that significant mixing between the eye and eyewall had progressed. Hindcast experiments of NEOGURI using the Japan Meteorological Agency operational mesoscale atmospheric model reproduced the flow field of the inner core similar to the observation. On the other hand, the simulated central pressure during the mature stage was higher than the observation. |