Collaborative Research: Linking sea ice and snow cover changes to Greenland mass balance through stratospheric and tropospheric pathways

格陵兰冰盖的融化已经是海平面上升的最大单一因素，而且融化的速度还在加快。与此同时，北极作为一个整体正在经历前所未有的变化并创造新的纪录，包括北极海冰覆盖面积的减少，北半球积雪覆盖面积的减少和提前融化，以及地球上其他任何地方的总体变暖速度都超过了一倍。研究和了解北极不同组成部分(格陵兰、积雪和海冰)之间的联系机制，以及它们的变化是如何与大气相关并由大气驱动的，对于捕捉推动变化的物理过程是至关重要的。事实上，这是显著提高我们在不同变暖情景下估计北极未来演变和预测未来海平面上升的技能的关键方面之一。这项研究正在通过结合观测和建模工具来量化海冰、积雪、大气环流变化和格陵兰冰盖质量变化之间的关系。这包括对海冰复盖和积雪范围的现场观测，以及遥感产品和大气环流变化的估计以及气候模型的产出。我们还使用人工智能(例如，神经网络)来研究气候、大气模式和格陵兰变化之间的关系。最终，这项研究是在验证这样一个假设，即与海冰和积雪覆盖范围变化相关的大气环流变化通过调节降雪和表面融化来控制格陵兰冰盖的物质平衡。这项研究还为北极和中纬度之间的联系以及海冰和雪覆盖的变化如何影响北极以外的天气模式(包括美国)提供了新的见解。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Melting of the Greenland ice sheet is already the largest single contributor to sea level rise, and the rate of melt is accelerating. At the same time, the Arctic as a whole is experiencing unprecedented changes and setting new records, including the decline of Arctic sea ice cover, the decline and early snowmelt onset of Northern Hemisphere snow cover, and an overall warming at a rate more than double anywhere else on the planet. Studying and understanding the mechanisms linking the different Arctic components (Greenland, snow cover, and sea ice in the case of this research) and how, in turn, their changes are related to and driven by the atmosphere is fundamental to capture the physical processes driving the changes. This is, indeed, one of the key aspects to considerably improve our skills in estimating the future evolution of the Arctic under different warming scenarios and in projecting future sea level rise.This research is quantifying the relationships between sea ice, snow cover, atmospheric circulation changes and mass changes over the Greenland ice sheet through a combination of observational and modeling tools. These include in situ observations of sea ice cover and snow extent as well as remote sensing products and estimates of atmospheric circulation changes and outputs from climate models. We also use artificial intelligence (e.g., neural networks) to examine relationships between climate, atmospheric patterns and Greenland changes. Ultimately, this research is testing the hypothesis that atmospheric circulation changes associated with sea ice and snow cover extent variability control the mass balance of the Greenland ice sheet by modulating snowfall and surface melting. This research is also providing new insights on the linkages between the Arctic and mid-latitudes and how sea ice and snow cover changes might affect weather patterns outside the Arctic, including the United States.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.