Year: 2024
Type: article
Abstract: Typhoon Chanthu (2021) underwent a unique rapid intensification (RI) when it moved northward offshore east of Taiwan under a northerly vertical wind shear. The recirculating flow of Chanthu’s outer circulation around south Taiwan led to the observed stronger convection at the offshore side of the typhoon. A multi-resolution simulation of MPAS has successfully captured the RI of Chanthu and indicated no RI in the absence of Taiwan terrain. Sensitivity tests help to explore the role of terrain-induced recirculating flow in the induced RI. Based on the solution of the extended Sawyer–Eliassen (SE) equation, diabatic heating contributes the most to the lower-tropospheric eyewall spinup in the nonlinear simulation. Asymmetric convection is enhanced in downshear left quadrant by the strong convergence between the recirculating flow and the typhoon’s inner vortex, resulting in a stronger contribution to the spinup than in the other three quadrants. Such asymmetric convection configured at the offshore side of the inner typhoon provides the dynamic mechanism of Chanthu’s RI.
Source: Geoscience Letters
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,340
OpenAlex ID: W4404563251