Global snow drought hot spots and characteristics
Global snow drought hot spots and characteristics
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DOI：
10.1073/pnas.1915921117
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发表时间：
2020-08-18
影响因子：
11.1
通讯作者：
Aghakouchak, Amir
中科院分区：
文献类型：
--
作者：
Huning, Laurie S.;Aghakouchak, Amir
雪在全球水资源、气候和地球化学过程中发挥着重要作用;然而，目前还没有全球性的雪旱评估。干旱持续时间和强度的变化会对一个地区的生态系统、粮食和水安全、农业、水电和社会经济产生重大影响。我们描述了1980年至2018年全球雪旱（雪水当量赤字）的持续时间和强度及其分布差异。我们发现，雪干旱变得更加普遍，加剧，并延长整个美国西部（WUS）。俄罗斯东部、欧洲和WUS成为雪旱的热点地区，在1980年下半年至2018年期间，雪旱持续时间分别延长了2%、16%和28%。在记录的后半部分，这些地区表现出更高的概率（相对于记录的前半部分），雪干旱超过第一阶段的平均强度3%，4%和15%。然而，兴都库什山脉和中亚、热带外安第斯山脉、大喜马拉雅山脉和巴塔哥尼亚的平均雪旱持续时间却减少了（百分比变化）（分别为-4%、-7%、-8%和-16%）。虽然我们不试图通过详细的归因分析来区分自然和人类的影响，但我们讨论了一些相关的物理过程（例如，北极放大和极涡运动），可能有助于观察到的雪干旱特征的变化。我们还展示了我们的框架工作如何通过检查两个雪赤字，在WUS（2014/2015）和阿富汗（2017/2018）构成了巨大的社会经济挑战，可以促进干旱监测和评估。
Snow plays a fundamental role in global water resources, climate, and biogeochemical processes; however, no global snow drought assessments currently exist. Changes in the duration and intensity of droughts can significantly impact ecosystems, food and water security, agriculture, hydropower, and the socioeconomics of a region. We characterize the duration and intensity of snow droughts (snow water equivalent deficits) worldwide and differences in their distributions over 1980 to 2018. We find that snow droughts became more prevalent, intensified, and lengthened across the western United States (WUS). Eastern Russia, Europe, and the WUS emerged as hot spots for snow droughts, experiencing similar to 2, 16, and 28% longer snow drought durations, respectively, in the latter half of 1980 to 2018. In this second half of the record, these regions exhibited a higher probability (relative to the first half of the record) of having a snow drought exceed the average intensity from the first period by 3, 4, and 15%. The Hindu Kush and Central Asia, extratropical Andes, greater Himalayas, and Patagonia, however, experienced decreases (percent changes) in the average snow drought duration (-4, -7, -8, and -16%, respectively). Although we do not attempt to separate natural and human influences with a detailed attribution analysis, we discuss some relevant physical processes (e.g., Arctic amplification and polar vortex movement) that likely contribute to observed changes in snow drought characteristics. We also demonstrate how our frame-work can facilitate drought monitoring and assessment by examining two snow deficits that posed large socioeconomic challenges in the WUS (2014/2015) and Afghanistan (2017/2018).