Continuing Support of Sustainable Observations of Thermal State of Permafrost in North America and Russia: The U.S. Contribution to the Global Terrestrial Network for Permafrost

永久冻土是指连续两年以上保持在0摄氏度以下的土壤、岩石或沉积物，其覆盖范围和冰含量各不相同。当永久冻土变暖和融化时，任何埋在地下的冰都会融化。这可能导致地面塌陷、地形变化和基础设施损坏。冻土融化也会改变碳循环的动态，影响近地表水文，导致地表变得更湿或更干。为了了解永久冻土变暖的速度和位置，该项目支持在阿拉斯加，西伯利亚和加拿大北极群岛的250多个永久冻土监测点持续收集高质量的长期地面温度数据。为了改进地面变暖的检测，研究人员将在一些监测点补充传感器，以直接测量近地表永久冻土和地面之间的热通量。为了了解永久冻土变暖和地面沉降之间的关系，研究人员还将监测和绘制地貌变化沿着一条从南到北横跨亚北极和北极阿拉斯加的横断面。 该提案加强了国际多年冻土热状态观测站网络，并为全球陆地多年冻土网络和NSF北极数据中心提供了选定的多年冻土参数的一致性、代表性和高质量的标准化长期数据系列。该项目将在2019年至2023年期间继续维护和获取现有阿拉斯加和加拿大西北部永久冻土观测站网络的数据;继续在俄罗斯北极地区建立可持续的永久冻土观测站网络，并参与获取区域观测站的一套可比标准化数据;参与国际TSP项目的实施，作为美国对GTN-P的贡献;继续开发和更新阿拉斯加-俄罗斯永久冻土温度联合数据库，并向其他数据系统提供数据;并在五个地面观测点监测永久冻土退化对地貌的影响。该项目还将涉及一些本科生，培养一名博士生，指导一名博士后学者，并支持阿拉斯加和俄罗斯的K-12外展活动。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Permafrost, defined as soil, rock or sediment that remains below 0 degrees Celsius for more than two consecutive years, varies in coverage and ice content. When permafrost warms and thaws, any buried ground ice present melts. This can lead to ground surface caving, changes in terrain, and damage to infrastructure. Permafrost thaw can also change dynamics of carbon cycling and affect near-surface hydrology causing the ground surface to become wetter or drier. To understand how fast and where permafrost is warming, this project supports the ongoing collection of high-quality, long-term data on ground temperature at more than 250 permafrost monitoring sites in Alaska, Siberia, and the Canadian Arctic Archipelago. To refine detection of ground warming, the investigators will supplement some monitoring sites with sensors to directly measure the heat flux between the near-surface permafrost and ground surface. To understand the relationship between permafrost warming and ground surface subsidence, the investigators will also monitor and map geomorphological changes along a transect that runs south to north across sub-Arctic and Arctic Alaska. This proposal strengthens the International Network of Thermal State of Permafrost (TSP) Observatories and provides the Global Terrestrial Network for Permafrost (GTN-P) and the NSF Arctic Data Center with a consistent, representative, and high quality standardized long-term data series of selected permafrost parameters. This project will continue to maintain and acquire data from the existing Alaskan and Northwest Canadian network of permafrost observatories for the period 2019 to 2023; continue to develop a sustainable network of permafrost observatories in the Russian Arctic and participate in the acquisition of a comparable set of standardized data from regional observatories; participate in the implementation of the international TSP project as the US contribution to the GTN-P; continue to develop and update a joint Alaska-Russian permafrost temperature database and provide data to other data systems; and monitor the geomorphological impact of permafrost degradation at five surface observation sites. This project will also involve a number of undergraduate students, train one PhD student, mentor a postdoctoral scholar, and support K-12 outreach activities in both Alaska and Russia.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.