Effects of horizontal resolution and air–sea flux parameterization on the intensity and structure of simulated Typhoon Haiyan (2013)
Effects of horizontal resolution and air–sea flux parameterization on the intensity and structure of simulated Typhoon Haiyan (2013)
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DOI：
10.5194/nhess-19-1509-2019
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发表时间：
2019-07
影响因子：
4.6
通讯作者：
M. Kueh;Wen-Mei Chen;Yang-Fan Sheng;Simon C. Lin;Tso-Ren Wu;E. Yen;Y. Tsai;Chuan-Yao Lin
中科院分区：
文献类型：
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作者：
M. Kueh;Wen-Mei Chen;Yang-Fan Sheng;Simon C. Lin;Tso-Ren Wu;E. Yen;Y. Tsai;Chuan-Yao Lin
抽象的。本文以超强台风“海燕”(2013)为例，研究了水平分辨率和地面通量公式对台风强度和结构模拟的影响。天气研究和预报模式中的三套地表通量公式在网格间距分别为1、3和6公里的情况下进行了检验。提高分辨率和更合理的地面通量公式都可以改善台风强度模拟，但它们对风暴结构的影响不同。动量转移系数的减少和热焓转移系数的增加相结合，有更大的可能产生更强的风暴。当适当减小网格间距以产生密集和收缩的眼壁结构时，更合理的表面通量公式的这种积极作用可以有效地增强。随着分辨率的提高，眼壁变得更加竖直，向内收缩。眼壁上升气流中心尺寸缩小，下沉气流区域增大，上升气流和下沉气流都变得更加强烈。因此，眼壁内的增强对流核心是由相当小一部分空间区域内的更强烈的上升气流驱动的。眼壁的这种收缩与高层变暖过程有关，这可能部分归因于从强烈对流中心排出的空气。上升气流空间尺度的这种分辨率依赖于由网格间距决定的模式有效分辨率。
Abstract. This study investigates the effects of horizontal resolution and surface flux formulas on typhoon intensity and structure simulations through the case study of the Super Typhoon Haiyan (2013). Three sets of surface flux formulas in the Weather Research and Forecasting Model were tested using grid spacings of 1, 3, and 6 km. Increased resolution and more reasonable surface flux formulas can both improve typhoon intensity simulation, but their effects on storm structures differ. A combination of a decrease in momentum transfer coefficient and an increase in enthalpy transfer coefficients has greater potential to yield a stronger storm. This positive effect of more reasonable surface flux formulas can be efficiently enhanced when the grid spacing is appropriately reduced to yield an intense and contracted eyewall structure. As the resolution increases, the eyewall becomes more upright and contracts inward. The size of updraft cores in the eyewall shrinks, and the region of downdraft increases; both updraft and downdraft become more intense. As a result, the enhanced convective cores within the eyewall are driven by more intense updrafts within a rather small fraction of the spatial area. This contraction of the eyewall is associated with an upper-level warming process, which may be partly attributed to air detrained from the intense convective cores. This resolution dependence of spatial scale of updrafts is related to the model effective resolution as determined by grid spacing.