In the Great Lakes basin of North America, snow plays a critical role in the regional hydroclimate, where snow ablation events can serve both as a resource and a hazard. The frequency and magnitude of an ablation event is governed by the availability of meteorological conditions to ablate snow, and the physical presence of snow to be ablated. While the meteorological conditions leading to ablation have been well documented, examining changes in atmospheric conditions alone have been unable to completely explain observed ablation trends. As such, this study applies a gridded snow depth dataset to evaluate snow depth variability, while speaking to the implications of such variability on ablation frequency and water resources. Snow cover is present in the basin from November – April, with the more northerly regions (Lake Superior and Lake Huron basins) exhibiting a deeper and more seasonally-persistent snowpack. Seasonal basin-wide snow depth decreased by approximately 25% from 1960 to 2009, with some of the most significant decreases occurring north of Lake Superior. Surface air temperatures are negatively associated snow depth, and warming temperatures are likely contributing to snow depth declines. These regional decreases in snow depth spatially corroborate previously observed decreases in the frequency of ablation events in the basin, and highlight the importance of examining both snow cover and meteorological conditions when seeking to explain snow ablation variability. The results from this study can be applied to inform water resource management decisions in the region.

在北美的大湖流域，积雪在该地区的水文气候中起着关键作用，那里的融雪事件既可作为资源，也可作为危险。消融事件的发生频率和强度取决于消融雪的气象条件的可用性以及要消融雪的物理存在。尽管导致烧蚀的气象条件已得到充分记录，但仅检查大气条件的变化仍无法完全解释观察到的烧蚀趋势。因此，本研究应用网格化的雪深数据集来评估雪深的变异性，同时谈到这种变异性对消融频率和水资源的影响。11月至4月期间流域存在积雪，偏北地区（苏必利尔湖盆地和休伦湖盆地）则表现出更深，更持久的积雪。从1960年到2009年，整个盆地的季节性降雪深度减少了约25％，其中最明显的减少发生在苏必利尔湖以北。地表空气温度与降雪深度成负相关，而变暖的温度很可能导致降雪深度下降。这些区域性积雪深度的减少在空间上证实了先前观察到的该盆地消融事件发生频率的下降，并突出了在试图解释积雪消融变化时检查积雪和气象条件的重要性。这项研究的结果可用于为该地区的水资源管理决策提供依据。