[U18-05] Typhoon observations using an aircraft from the upper troposphere in the T-PARCII project
Keywords:Aircraft observation, typhoon, dropsonde
We utilized a commercial jet aircraft Gulfstream-II (G-II) of Diamond Air Service (DAS). In 2017, we penetrated 3 times into the inner core region (eye) of the intense typhoon Lan (T201721). In 2018, we penetrated 6 time into the eye of the intense typhoon Trami (T201824). Total 9 times penetration into the eye safely without severe turbulence and approximately 90 times dropsonde observations are conducted at the center of the eye and its surrounding region from a height of 13.8 km. Central pressure of typhoons is observed by dropsondes and compared with the estimated value by the JMA (Dovolak method). In the case of the Lan, the observed central pressure slightly increases from 926 hPa on October 21 to 928 hPa on 22. On the other hand, the JMA best-track data indicated that the central pressure decreases from 935 hPa on October 21 to 915 hPa on 22. The observations also shows a significant double warm core structure in the eye. In the case of the Trami, significant weakening of its intensity from September 25 to 26 with a large change of eye diameter from 60 km to 200 km. The thermodynamic structure in the eye of the Trami is quite different from that of the Lan.