This study investigated the representation of surface winds in complex terrain during the passage of Typhoon Sondga (2004) in downscaling simulations with the horizontal grid spacing of 200 m. The mountainous areas in Hokkaido where forest damages occurred in the typhoon event were chosen for the present analysis. The 200 m grid simulations were compared with the simulations with the grid spacing of 1 km. The 200 m grid simulations clearly indicated more enhanced and more frequent extremes both in the stronger and weaker ranges of surface winds than the 1 km grid case. Both in the 200 m grid and 1 km grid cases, the mean and maximum winds in the analysis areas during the simulated time period increase with the increase in the terrain slope angle, but in the 200 m grid case, the relationships of the mean and maximum winds against the terrain slope angle includes wide scatter. In this way, the response of the wind representations to the grid spacing appears differently between the 200 m and 1 km grid cases. A parameter characterized subgrid-scale orography was used to quantify the influences of the terrain complexity on surface winds, demonstrating that the area-maxima and spatial variance of surface winds are more enhanced with the increase in the subgrid-scale orography in the higher-resolution case. It is suggested that the high-resolution simulations at the 200 m grid highlight the fluctuating nature of surface winds in complex terrain, because of the better representation of the model terrain at 200 m. Benefits of the representation of surface winds in simulations at the resolution on the order of 100 m are due to the better representation of complex terrain, which enables to quantitatively assess the impacts of strong winds on forest and natural vegetation in complex terrain.

中文翻译：

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高分辨率降尺度实验对评估复杂地形中局部尺度的强风危害的益处：台风松达（2004年）的案例研究

这项研究调查了台风桑德加（2004）通过的降尺度模拟中水平地面网格间距为200 m时复杂地形中表面风的表示。本次分析选择了在台风事件中发生森林破坏的北海道山区。将200 m网格模拟与网格间距为1 km的模拟进行了比较。200 m网格模拟清楚地表明，与1 km网格情况相比，在强风和弱风范围内，地面风的增强程度和频度更高。在200 m网格和1 km网格的情况下，模拟时间段内分析区域的平均风和最大风都随着地形坡度角的增加而增加，但是在200 m网格的情况下，平均风和最大风与地形坡度角的关系包括较大的散射。这样，在200 m和1 km的网格情况下，风表示对网格间距的响应出现了不同。使用参数化的次网格规模地形来量化地形复杂性对地表风的影响，表明随着子网格规模地形的增加，地表风的面积最大值和空间变化会随着分辨率的提高而增强。案件。建议在200 m网格上进行高分辨率模拟，因为在200 m上可以更好地表示模型地形，因此可以显示复杂地形中表面风的波动性质。