报告简介：

The balanced contribution to the intensification of a tropical cyclone simulated in the three-dimensional, nonhydrostatic, full-physics model TCM4, in particular the spin-up of the outer core circulation, is investigated by solving the Sawyer-Eliassen equation and by computing terms in the azimuthal-mean tangential wind tendency equation. Results demonstrate that the azimuthal-mean secondary circulation and the spin-up of the mid-tropospheric outer core circulation in the simulated tropical cyclone are well captured by balance dynamics. The mid-tropospheric inflow develops in response to diabatic heating in mid-upper tropospheric stratiform (anvil) clouds outside the eyewall in active spiral rainbands and transports absolute angular momentum inward to spin up the outer core circulation. Although the azimuthal-mean diabatic heating rate in the eyewall is the largest, its contribution to radial winds and thus the spin-up of outer core circulation in the mid-troposphere is rather weak. This is because the high inertial stability in the inner core region resists the radial inflow in the mid-troposphere, limiting the inward transport of absolute angular momentum. The result thus suggests that diabatic heating in spiral rainbands is the key to the continued growth of the storm scale circulation.

主讲人简介：

Prof. Hironori Fudeyasu earned his Ph.D. in Earth and Planetary Sciences from the Graduate School of Science at Kyoto University in 2003. He currently serves as the Director of the Typhoon Science and Technology Research Center (TRC) at the Institute for Multidisciplinary Sciences and as a Professor in the Graduate School of Education at Yokohama National University (YNU). His research focuses on various aspects of tropical cyclone (TC) dynamics, including TC intensity, rapid intensification, eyewall formation, TC-ocean interaction, and TC-terrain interaction.

Prof. Fudeyasu became the inaugural Director of TRC, which was established in 2021 at YNU, leading a team of over 50 typhoon researchers from various universities and research institutions across Japan. Notably, Prof. Fudeyasu has contributed to the establishment of the Moonshot project, which began in 2022 supported by The Japan Science and Technology Agency. Prof. Fudeyasu currently serves as the Program Manager for the core research, overseeing a team of 120 researchers. Prof. Fudeyasu has published over 50 peer-reviewed papers in SCI journals. In 2019, Prof. Fudeyasu received the Academic Award from YNU. In 2020, he was honored with the Grand Prize, the highest accolade of the 29th Earth Environment Award organized by the Fuji Sankei Group in Japan.