Shorter cyclone clusters modulate changes in European wintertime precipitation extremes
Shorter cyclone clusters modulate changes in European wintertime precipitation extremes
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DOI：
10.1088/1748-9326/abbde7
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发表时间：
2020-12-01
影响因子：
6.7
通讯作者：
Shepherd, Theodore G.
中科院分区：
文献类型：
--
作者：
Bevacqua, Emanuele;Zappa, Giuseppe;Shepherd, Theodore G.
冬季气旋群（即连续穿越同一地区的气旋）产生的极端降水可能导致欧洲发生洪水和破坏性的社会经济影响。以前的研究表明，这些事件的未来变化方向在气候模型中是不确定的。通过采用基于影响的累积降水极端的度量，我们表明，预测的气旋集群，而不是广泛的强大，即一致的符号，跨模型。一项新的物理诊断表明，预计整个欧洲的累积极端降水量平均仅增长+1.0%/K，尽管每个气旋的平均降水量增加+4.7%/K。这是由于与冬季风暴减少有关的集群气旋数量减少，其程度从北方到南欧各不相同，取决于未来大气环流变化的情况。忽略集群气旋数量的变化，即假设累积极端降水量将随着每个气旋的平均降水量而变化，将导致高估整个欧洲受冬季累积极端降水量增加影响的人口1.3亿至4.9亿。
Wintertime extreme precipitation from cyclone clusters, i.e. consecutive cyclones moving across the same region, can lead to flooding and devastating socio-economic impacts in Europe. Previous studies have suggested that the future direction of the changes in these events are uncertain across climate models. By employing an impact-based metric of accumulated precipitation extremes, we show that projections of cyclone clusters are instead broadly robust, i.e. consistent in sign, across models. A novel physical diagnostic shows that accumulated precipitation extremes are projected to grow by only +1.0 %/K on average across Europe, although the mean precipitation per cyclone increases by +4.7 %/K. This results from a decreased number of clustered cyclones, associated with decreased wintertime storminess, the extent of which varies from northern to southern Europe and depends on the future storyline of atmospheric circulation change. Neglecting the changes in the number of clustered cyclones, i.e. assuming that accumulated precipitation extremes would change as the mean precipitation per cyclone, would lead to overestimating the population affected by increased accumulated wintertime precipitation extremes by 130-490 million across Europe.