講演情報
[U15-P07]Aircraft observation of tropical cyclones in T-PARCII★Invited Papers
*伊藤 耕介1,3、坪木 和久2,3 (1.京都大学防災研究所、2.名古屋大学宇宙地球環境研究所、3.横浜国立大学台風科学技術研究センター)
Accurate intensity estimation of violent tropical cyclones (TCs) in the western North Pacific has long been limited by the lack of in situ observations, resulting in significant discrepancies among best-track datasets after the termination of U.S. aircraft reconnaissance. The Tropical Cyclones-Pacific Asian Research Campaign for the Improvement of Intensity Estimations/Forecasts (T-PARCII), initiated in 2016, introduced a new strategy for upper-tropospheric eyewall-penetrating aircraft missions using a Gulfstream-II and Gulfstream-IV equipped with a newly developed dropsonde system. Flights were conducted at approximately 14 km altitude to directly observe the inner-core structure of intense typhoons.
During missions targeting TCs Lan (2017), Trami (2018), Mindulle (2021), Nanmadol (2022), Balijat (2024), and Neoguri (2025) multiple eyewall penetrations and over 100 dropsondes were deployed. Observations revealed detailed inner-core thermodynamic structures, including a double warm-core configuration in Lan and short-lived deep convective clouds within the eye of Trami. Dropsonde-derived minimum sea level pressures showed discrepancies of 10–15 hPa compared to Dvorak-based estimates, highlighting uncertainties in operational intensity analyses. Assimilation of dropsonde data using a 4DVar system improved track forecasts and heavy rainfall prediction. Coupled atmosphere–ocean modeling further demonstrated the importance of air–sea interaction in intensity evolution. These results demonstrate the critical role of direct aircraft observations in improving TC intensity estimation, forecast skill, and physical understanding of inner-core dynamics.
During missions targeting TCs Lan (2017), Trami (2018), Mindulle (2021), Nanmadol (2022), Balijat (2024), and Neoguri (2025) multiple eyewall penetrations and over 100 dropsondes were deployed. Observations revealed detailed inner-core thermodynamic structures, including a double warm-core configuration in Lan and short-lived deep convective clouds within the eye of Trami. Dropsonde-derived minimum sea level pressures showed discrepancies of 10–15 hPa compared to Dvorak-based estimates, highlighting uncertainties in operational intensity analyses. Assimilation of dropsonde data using a 4DVar system improved track forecasts and heavy rainfall prediction. Coupled atmosphere–ocean modeling further demonstrated the importance of air–sea interaction in intensity evolution. These results demonstrate the critical role of direct aircraft observations in improving TC intensity estimation, forecast skill, and physical understanding of inner-core dynamics.