Abstract The supergradient winds that may have severe implications on the wind design of high-rise buildings have been commonly observed in the hurricane boundary layer. However, the widely-used log-law or power-law wind profile excludes the supergradient-wind region in which the tangential winds are larger than the gradient winds. Although high-fidelity, nonlinear hurricane wind models may well capture the supergradient winds, high computational demand is needed for each simulation. Recently developed linear, height-resolving hurricane wind models, while can efficiently consider the existence of supergradient winds, significantly underestimate them due essentially to the ignorance of vertical advection term in the governing equations. A number of studies have actually demonstrated that the vertical advection is a major contributor to the transfer of horizontal momentum to the supergradient region. To this end, a refined analytical model that simultaneously integrates the horizontal advection, vertical advection and vertical diffusion terms into the governing equations is developed for accurately and efficiently estimating the hurricane supergradient winds. The important role of the vertical wind speed in determining the horizontal wind speeds (including supergradient winds) in the hurricane boundary layer is highlighted. Since the horizontal and vertical wind components are mutually dependent, the iteration technique is utilized to solve the proposed analytical model. The consideration of the vertical advection results in intensified supergradient winds that are consistent with the observations. Furthermore, a strong outflow region in the vicinity of the radius of maximum winds due to the supergradient winds can be obtained. Due to its simplicity and computational efficiency, the developed analytical model can be easily implemented in the Monte Carlo simulations for the rapid assessment of hurricane wind risk to coastal structures, especially to high-rise buildings.

中文翻译：

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一种快速估计飓风超梯度风的分析模型

摘要 在飓风边界层普遍观察到可能对高层建筑的风设计产生严重影响的超梯度风。然而，广泛使用的对数定律或幂律风廓线排除了切向风大于梯度风的超梯度风区。尽管高保真、非线性飓风风模型可以很好地捕捉超梯度风，但每次模拟都需要很高的计算需求。最近开发的线性、高度分辨飓风风模型虽然可以有效地考虑超梯度风的存在，但主要由于控制方程中垂直平流项的无知而大大低估了它们。许多研究实际上表明，垂直平流是水平动量向超梯度区域转移的主要贡献者。为此，开发了一个精炼的分析模型，同时将水平平流、垂直平流和垂直扩散项整合到控制方程中，以准确有效地估计飓风超梯度风。突出了垂直风速在确定飓风边界层水平风速（包括超梯度风）中的重要作用。由于水平和垂直风分量相互依赖，因此利用迭代技术来求解所提出的分析模型。对垂直平流的考虑导致与观测结果一致的增强的超梯度风。此外，由于超梯度风，可以获得在最大风半径附近的强流出区域。由于其简单性和计算效率，开发的分析模型可以很容易地在蒙特卡罗模拟中实施，以快速评估飓风对沿海结构，尤其是高层建筑的风险。