Preliminary study of an intense rainfall episode in Corsica, 14 September 2006
Preliminary study of an intense rainfall episode in Corsica, 14 September 2006
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对 2006 年 9 月 14 日科西嘉岛强降雨事件的初步研究
DOI：
10.5194/adgeo-16-125-2008
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发表时间：
2008
影响因子：
--
通讯作者：
S. Argence
中科院分区：
文献类型：
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作者：
D. Lambert;S. Argence
摘要。本文介绍了2006年9月14日科西嘉岛强降雨事件的初步研究。采用两组初始场和耦合场对法国非流体静力中尺度模式MESO-NH进行了运行。使用了三个交互式双向嵌套域，网格点分别为150×120、150×150和125×200，网格尺寸分别为50公里、10公里和2公里。定义了50个垂直层次。从地面到2000 m，垂直分辨率为60 m，而在600 m以上。对流对粗域和中间域进行参数化，并假设对2 km网格进行显式解析。在大尺度上，两种模拟都很好地代表了这种情况，但在精细尺度上，它们表现出显著的差异。与观测值的比较不允许对两个模拟进行区分。尽管通常与暴雨相关的主要高层动力成分在两个模拟中都存在，但它们的精细尺度演变并没有得到很好的再现。在地表附近，两种模拟之间存在显著差异。与对流现象相关的垂直运动场在最内层区域是不同的。在一个模拟中，东海岸的冷池作为暖锋与海上的主要降雨区有关，而在第二个模拟中，科西嘉山脉似乎作为屏障，导致内陆降雨。这项初步研究为未来的敏感性试验提供了前景。例如，计划对高层动力学、海温和更好地描述地形的影响进行调查。
Abstract. A preliminary study of the 14 September 2006 heavy rainfall episode in Corsica is presented. Two sets of initial and coupling fields were used to run the French non-hydrostatic mesoscale model, MESO-NH. Three interactive 2-way nested domains were used, having 150×120, 150×150 and 125×200 grid points and 50 km, 10 km and 2 km mesh sizes. 50 vertical levels were defined. From ground level to 2000 m, the vertical resolution was 60 m, whereas it was 600 m above. Convection was parameterized for the coarser and intermediate domains and assumed to be explicitly resolved for the 2 km grid. At large scale, the situation is well represented by both simulations but, at the fine scale, they present significant differences. Comparison with the observations did not allow the two simulations to be discriminated. Even though the main high-level dynamical ingredients usually associated with rain storms were present in both simulations, their fine scale evolution was not reproduced well. Near the surface, there were significant differences between the two simulations. Vertical motion fields associated with convective phenomena were different in the innermost domain. A cold pool acting as a warm front off the east coast was associated with the main rainfall area over the sea in one simulation whereas in the second one, it seemed that the Corsican mountains acted as a barrier, leading to inland rainfall. This preliminary study gives perspectives for future sensitivity tests. For example, an investigation is planned of the influence of the high level dynamics, the SST and a better description of the orography.