Amplified seasonal range in precipitation minus evaporation
Amplified seasonal range in precipitation minus evaporation
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DOI：
10.1088/1748-9326/acea36
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发表时间：
2023-09-01
影响因子：
6.7
通讯作者：
Allan, Richard P.
中科院分区：
文献类型：
--
作者：
Allan, Richard P.
气候变暖正在加剧全球水循环，包括大气和地表之间的淡水通量，这是由降水减去蒸发（P-E）决定的。淡水的过剩或不足会影响社会和生态系统，因此监测和了解P-E模式及其季节范围在地球仪上如何变化以及为什么变化是很重要的。在这里，年最大和最小P-E及其变化诊断全球陆地和海洋使用基于观测的数据集和CMIP 6气候模式实验涵盖1950-2100年。除北极、中纬度海洋和热带暖池外，地球仪大部分地区的季节性最小P-E为负值。在全球平均值中，在中等温室气体排放情景的集合平均值中，从1995-2014年到2080-2100年，P-E最大值增加，P-E最小值减少约3%-4%。在陆地上，1960-2020年的数据集之间的一致性较低，但在未来的预测中，P-E的季节范围会增加。年最大和最小P-E的未来变化模式在性质上与现今趋势相似，最大P-E在赤道带和高纬度地区增加，在副热带沉降带减少。这增加了对未来更加多变和极端的水循环预测的信心，但也突出了这种陆地响应的不确定性。
Climate warming is intensifying the global water cycle, including the rate of fresh water flux between the atmosphere and the surface, determined by precipitation minus evaporation (P-E). Surpluses or deficits of fresh water impact societies and ecosystems, so it is important to monitor and understand how and why P-E patterns and their seasonal range are changing across the globe. Here, annual maximum and minimum P-E and their changes are diagnosed globally over land and ocean using observation-based datasets and CMIP6 climate model experiments covering 1950-2100. Seasonal minimum P-E is negative across much of the globe, apart from the Arctic, mid-latitude oceans and the tropical warm pool. In the global mean, P-E maximum increases and P-E minimum decreases by around 3%-4% per C-& LCIRC; of global warming from 1995-2014 to 2080-2100 in the ensemble mean of an intermediate greenhouse gas emission scenario. Over land, there is less coherence across the 1960-2020 datasets, but an increase in the seasonal range in P-E emerges in future projections. Patterns of future changes in annual maximum and minimum P-E are qualitatively similar to present day trends with increases in maximum P-E in the equatorial belt and high-latitude regions and decreases in the subtropical subsidence zones. This adds confidence to future projections of a more variable and extreme water cycle but also highlights uncertainties in this response over land.