[A-AS02] Advances in Tropical Cyclone Research: Past, Present, and Future

[AAS02-02] Two-day Consecutive Typhoon Aircraft Observations Capturing Development and Phase Transition to an Extratropical Cyclone

*Sachie Kanada¹, Kazuhisa Tsuboki¹, Masaya Kato¹, Soichiro Hirano², Satoki Tsujino³, Munehiko Yamaguchi³ (1.Nagoya University, 2.Kyoto University, 3.Meteorological Research Institute)

Keywords:Toropical cyclone, Aircraft observation, Dropsonde, Typhoon

Tropical cyclones (TCs) are hazardous weather systems. With recent increase in sea surface temperature (SST) in a higher-latitude, understanding how a TC develops in midlatitude is important because TC activity intensifies over warmer sea. Our 5-min interval observations by novel meteorological sondes launched from an aircraft flying at an altitude of 13,000 m for two consecutive days captured a TC development in warming mid-latitude and rapid structural changes due to the northern baroclinic zone over steeply decreasing SST. On October 9, over warm sea, Typhoon Barijat (2024) near 30^oN developed a group of tall, vigorous, and upright meso-gamma convection commonly termed the vortical hot tower (VHT) in northeastern side near the storm center. The VHT with positive vorticity developed to the tropopause, warming and moistening the deep layers. On October 10, in contrast, a cold and dry mid-level descending jet intruded from the west crossing the storm core-region. Our vertically high-resolution 5-min interval observations indicated that the descending jet enhanced mid-to-low level warm core by adiabatic heating, however, it eroded the VTH and led the TC to transit to an extratropical cyclone.