The 21st century decline in damaging European windstorms
The 21st century decline in damaging European windstorms
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DOI：
10.5194/nhess-16-1999-2016
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发表时间：
2016-08-29
影响因子：
4.6
通讯作者：
Maisey, Paul E.
中科院分区：
文献类型：
--
作者：
Dawkins, Laura C.;Stephenson, David B.;Maisey, Paul E.
欧洲破坏性风暴的减少导致 21 世纪的保险损失减少。通过识别具有破坏性的风暴特征并调查近年来该特征如何以及为何发生变化来探索这种下降。这项新颖的探索基于 6103 个高分辨率模型生成的历史足迹（1979-2014），代表整个欧洲领域。风暴的足迹被定义为风暴持续时间内在一组空间位置发生的最大阵风速度。陆地上超过 20 ms(-1) 的足迹面积 A(20) 被证明是风暴损害的良好预测指标。进入 21 世纪，这种破坏性特征有所减弱，原因是西北欧超过 20 ms(-1) 的风暴相对频率在统计上显着下降，但南欧的风暴频率有所增加。这是因为该区域中的位置阵风足迹风速分布的分位数下降到约 18 ms(-1) 以上。此外，在 21 世纪观察到风暴事件数量的变化有所增加。A(20) 的大部分变化可以通过北大西洋涛动 (NAO) 来解释。冬季总 A(20) 与冬季平均海平面压力之间的相关性类似于 NAO 模式，在欧洲上空向东移动，并且冬季总 A(20) 与冬季平均 NAO 之间存在很强的正相关关系（相关性为 0.715）。然而，相关模式的转变表明，其他变化模式也可能在风暴损失的变化中发挥作用。
A decline in damaging European windstorms has led to a reduction in insured losses in the 21st century. This decline is explored by identifying a damaging windstorm characteristic and investigating how and why this characteristic has changed in recent years. This novel exploration is based on 6103 high-resolution model-generated historical footprints (1979-2014), representing the whole European domain.The footprint of a windstorm is defined as the maximum wind gust speed to occur at a set of spatial locations over the duration of the storm. The area of the footprint exceeding 20 ms(-1) over land, A(20), is shown to be a good predictor of windstorm damage. This damaging characteristic has decreased in the 21st century, due to a statistically significant decrease in the relative frequency of windstorms exceeding 20 ms(-1) in north-western Europe, although an increase is observed in southern Europe. This is explained by a decrease in the quantiles of the footprint wind gust speed distribution above approximately 18 ms(-1) at locations in this region. In addition, an increased variability in the number of windstorm events is observed in the 21st century.Much of the change in A(20) is explained by the North Atlantic Oscillation (NAO). The correlation between winter total A(20) and winter-averaged mean sea-level pressure resembles the NAO pattern, shifted eastwards over Europe, and a strong positive relationship (correlation of 0.715) exists between winter total A(20) and winter-averaged NAO. The shifted correlation pattern, however, suggests that other modes of variability may also play a role in the variation in windstorm losses.