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标题：Shock‐like structures in the tropical cyclone boundary layer
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作者：Gabriel J. Williams ; Richard K. Taft ; Brian D. McNoldy 等
期刊名称：Journal of Advances in Modeling Earth Systems
电子版ISSN：1942-2466
出版年度：2013
卷号：5
期号：2
页码：1-16
DOI：10.1002/jame.20028
出版社：John Wiley & Sons, Ltd.
摘要：This paper presents high horizontal resolution solutions of an axisymmetric, constant depth, slab boundary layer model designed to simulate the radial inflow and boundary layer pumping of a hurricane. Shock‐like structures of increasing intensity appear for category 1–5 hurricanes. For example, in the category 3 case, the term in the radial equation of motion produces a shock‐like structure in the radial wind, i.e., near the radius of maximum tangential wind the boundary layer radial inflow decreases from approximately 22 m s−1 to zero over a radial distance of a few kilometers. Associated with this large convergence is a spike in the radial distribution of boundary layer pumping, with updrafts larger than 22 m s−1 at a height of 1000 m. Based on these model results, it is argued that observed hurricane updrafts of this magnitude so close to the ocean surface are attributable to the dry dynamics of the frictional boundary layer rather than moist convective dynamics. The shock‐like structure in the boundary layer radial wind also has important consequences for the evolution of the tangential wind and the vertical component of vorticity. On the inner side of the shock the tangential wind tendency is essentially zero, while on the outer side of the shock the tangential wind tendency is large due to the large radial inflow there. The result is the development of a U‐shaped tangential wind profile and the development of a thin region of large vorticity. In many respects, the model solutions resemble the remarkable structures observed in the boundary layer of Hurricane Hugo (1989).
关键词：shocks;tropical cyclone;hurricane eyewall;boundary layer