Musselman Keith N, Addor Nans, Vano Julie A, Molotch Noah P
Institute of Arctic and Alpine Research, University of Colorado Boulder, CO.
Geography, College of Life and Environmental Sciences, University of Exeter, Exeter, UK.
Nat Clim Chang. 2021;2021. doi: 10.1038/s41558-021-01014-9. Epub 2021 Apr 5.
In many mountainous regions, winter precipitation accumulates as snow that melts in spring and summer, providing water to one billion people globally. Climate warming and earlier snowmelt compromises this natural water storage. While snowpack trend analyses commonly focus on snow water equivalent (SWE), we propose that trends in accumulation season snowmelt serve as a critical indicator of hydrologic change. Here we compare long-term changes in snowmelt and SWE from snow monitoring stations in western North America and find 34% of stations exhibit increasing winter snowmelt trends (p < 0.05), a factor of three larger than the 11% showing SWE declines (p < 0.05). Snowmelt trends are highly sensitive to temperature and an underlying warming signal, while SWE trends are more sensitive to precipitation variability. Thus, continental-scale snow water resources are in steeper decline than inferred from SWE trends alone. More winter snowmelt will complicate future water resource planning and management.
在许多山区，冬季降水以积雪的形式积累，在春季和夏季融化，为全球10亿人提供水源。气候变暖和积雪提前融化危及了这种天然的水储存。虽然积雪趋势分析通常侧重于雪水当量（SWE），但我们认为积累季节的融雪趋势是水文变化的关键指标。在此，我们比较了北美西部积雪监测站融雪和雪水当量的长期变化，发现34%的站点冬季融雪趋势呈上升趋势（p < 0.05），这一比例是雪水当量下降（p < 0.05）的11%的三倍。融雪趋势对温度和潜在的变暖信号高度敏感，而雪水当量趋势对降水变率更敏感。因此，大陆尺度的雪水资源下降速度比仅从雪水当量趋势推断的要快得多。更多的冬季融雪将使未来的水资源规划和管理变得更加复杂。
