Evolution of convective characteristics during tropical cyclogenesis
Evolution of convective characteristics during tropical cyclogenesis
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DOI：
10.1002/qj.4011
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发表时间：
2021-02
影响因子：
8.9
通讯作者：
G. Kilroy
中科院分区：
文献类型：
--
作者：
G. Kilroy
四个理想化的高分辨率（500 M水平网格间距），数值模拟用于研究热带气旋期间对流结构的演变。无论实验设置如何云量占主导地位。内核中细胞中产生的反气旋涡度。对流和旋风涡度在低中间水平上占主导地位。 ·S -1）。在整个创世纪期间产生的涡旋偶极子。
Four idealized, high‐resolution (500 m horizontal grid spacing), numerical simulations are used to investigate the evolution of convective structures during tropical cyclogenesis. The simulations all begin with a weak initial axisymmetric cloud‐free vortex in a quiescent environment, but differ in the moisture level of the initial sounding and whether or not ice microphysical processes are considered. Irrespective of experimental setup, there is only a short period where shallow or congestus clouds dominate. The shallow cloud phase is slightly extended with the drier initial environmental sounding. The composite structure of the convective elements sampled changes markedly throughout the genesis period. For much of the genesis phase, vertical profiles of the mean convective cell show significant amounts of anticyclonic vorticity produced in cells in the inner core. Towards the end of the genesis phase, there is a large increase in the production of cyclonic vertical vorticity in inner‐core convection, and cyclonic vorticity becomes dominant at low‐mid levels. The evolution from roughly equal strength vertical profiles of cyclonic/anticyclonic vorticity at low‐mid levels to profiles where cyclonic vorticity dominates occurs at relatively low system wind speeds (Vmax less than 10 m·s−1). This finding indicates a change in the structure of vortical convection prior to rapid intensification. In outer‐core convection, there are roughly equal strength vertical vorticity dipoles produced throughout the genesis period.