Larger Spatial Footprint of Wintertime Total Precipitation Extremes in a Warmer Climate
Larger Spatial Footprint of Wintertime Total Precipitation Extremes in a Warmer Climate
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DOI：
10.1029/2020gl091990
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发表时间：
2021-04-28
影响因子：
5.2
通讯作者：
Mitchell, Dann
中科院分区：
文献类型：
--
作者：
Bevacqua, Emanuele;Shepherd, Theodore G.;Mitchell, Dann
同一地区多个地点同时出现极端潮湿的冬季可能会导致大范围的洪水和相关的社会经济损失。然而，气候评估很大程度上忽视了极端降水的空间范围（即附近地点同时经历极端降水的区域）及其未来变化。采用新的数千年气候模型模拟，我们表明，在升温 2.0 摄氏度和 1.5 摄氏度的情况下，北半球温带地区（即北纬 28 度 - 78 度纬度带）的冬季总降水极端范围将增加约 80%-90%。稳定在 1.5 摄氏度而不是 2.0 摄氏度将使平均增幅减少 1.7-2 倍。根据气候模型，增加的范围是由降水强度的增加而不是事件的空间组织的变化引起的。降水强度相对较小的百分比增加（例如，增加 4%）可能会导致空间范围的增长不成比例地增加 1-2 个数量级（增加 93%）。
The simultaneous occurrence of extremely wet winters at multiple locations in the same region can contribute to widespread flooding and associated socio-economic losses. However, the spatial extent of precipitation extremes (i.e., the area in which nearby locations experience precipitation extremes simultaneously) and its future changes are largely overlooked in climate assessments. Employing new multi-thousand-year climate model simulations, we show that under both 2.0 degrees C and 1.5 degrees C warming scenarios, wintertime total precipitation extreme extents would increase over about 80%-90% of the Northern Hemisphere extratropics (i.e., of the latitude band 28 degrees-78 degrees N). Stabilizing at 1.5 degrees C rather than 2.0 degrees C would reduce the average magnitude of the increase by 1.7-2 times. According to the climate model, the increased extents are caused by increases in precipitation intensity rather than changes in the spatial organization of the events. Relatively small percentage increases in precipitation intensities (e.g., by 4%) can drive disproportionately larger, by 1-2 orders of magnitude, growth in the spatial extents (by 93%).