Determining the Impact of Boundary Layer Schemes on the Secondary Circulation of Typhoon Faxai Using Radar Observations in the Gray Zone

• DOI: 10.1175/jas-d-22-0169.1
• Publication Date: 2022-12-22T15:22:01Z
• Authors: Yasutaka Ikuta; Masahiro Sawada; Masaki Satoh
• Keywords: Typhoon; Inflow

Abstract Using detailed radar observation data for Typhoon Faxai, which made landfall in the Tokyo metropolitan area 2019, a sensitivity test of boundary layer (BL) schemes numerical weather prediction (NWP) model was conducted gray-zone simulations with grid spacing 250 m. We compared results our using an NWP observations that captured BL and secondary circulation structures Faxai. used three based on Reynolds-averaged model, large-eddy simulation (LES) model: Mellor–Yamada–Nakanishi–Niino level 3 (MYNN3) scheme, Anisotropic Deardorff Model (ADM) (DDF) respectively. The turbulence kinetic energy smallest, inflow near Earth’s surface strongest, DDF scheme. This also produced values thickness were closest to reproduced horizontal roll whose scale larger than observation. Neither experiment MYNN3 scheme or ADM rolls, but parameterized seemed estimate effects rolls. However, their heights higher observed, suggesting are not appropriate m present case. These confirmed against LES 50 is used. In summary, this study provides insights into interpretation properties gray zone.