Impacts of Mountain Topography and Background Flow Conditions on the Predictability of Thermally Induced Thunderstorms and the Associated Error Growth
Impacts of Mountain Topography and Background Flow Conditions on the Predictability of Thermally Induced Thunderstorms and the Associated Error Growth
复制标题
山地地形和背景流条件对热诱发雷暴可预测性及相关误差增长的影响
DOI：
10.1175/jas-d-21-0331.1
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发表时间：
2023
影响因子：
3.1
通讯作者：
Takemi Tetsuya
中科院分区：
文献类型：
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作者：
Wu Pin-Ying;Takemi Tetsuya
使用天气研究和预报 (WRF) 模型在理想化配置中进行热诱发雷暴模拟，以研究相关的误差增长和可预测性。我们在不同的地形和背景风下进行了同卵双胞胎实验，以评估这些因素的影响。结果表明，山区地形抑制了对流发展早期误差的增长。这种地形效应对山脉几何形状和背景风很敏感：在山脉较高且较窄的情况下更为明显，并且在没有背景风的情况下很难看到。地形效应及其敏感性是由对流引发的不同性质造成的。然而，当湿对流持续增长并引发误差快速增长时，地形效应变得不那么明显。在对流活动达到最大之后，雷暴的可预测性就会受到限制。较小的初始误差或稍后开始模拟不会打破这种可预测性限制的时间安排。山区地形也对最大对流活动的时间和可预测性限制产生有限的影响。相反，背景流改变了对流演化和随后的可预测性。通过降雨评估的可预测性极限表明了地形效应的其他方面。在有山地的情况下，可以充分捕捉域尺度的降雨分布和强烈的累积降雨量。
Thermally induced thunderstorm simulations were conducted with the Weather Research and Forecasting (WRF) Model in an idealized configuration to investigate the associated error growth and predictability. We conducted identical twin experiments with different topography and background winds to assess the impacts of these factors. The results showed that mountain topography restrains error growth at the early stage of convection development. This topographic effect is sensitive to mountain geometry and background winds: it was more noticeable in cases with higher and narrower mountains and difficult to see without background wind. The topographic effect and its sensitivity resulted from the different natures of convection initiation. However, the topographic effect became less apparent when moist convection continued growing and triggered rapid error growth. The predictability of thunderstorms is then limited at the timing after the convective activity reached its maximum. A smaller initial error or starting a simulation at a later time did not break this timing of predictability limit. Mountain topography also limitedly affected the timing of the maximum convective activity and the predictability limit. In contrast, background flows changed the convection evolution and the following predictability. The predictability limit assessed by rainfall suggested other aspects of the topographic effect. The domain-scale rainfall distribution and the intense accumulated rainfall can be adequately captured in the presence of mountains.