COLLABORATIVE RESEARCH: Ice Regime Shifts of Arctic Lakes Drive Interactions and Feedbacks with Permafrost and Climate

在北极低地地区，浅湖和池塘可能覆盖高达40%的陆地表面。传统上，这些水体中的许多在冬季会冻结成固体，从而保护了湖底永久冻土，并使土壤碳储量在深处保持不动。稍微深一点的湖泊在浮冰下保留了一些液态水，在连续的永久冻土中形成了深度解冻区。有证据表明，由于冬季变暖、多雪，冰层变薄，使许多床状冰湖变成了浮冰。如果这种状态转变在湖泊丰富的景观中变得普遍，那么永久冻土解冻以及水分和热通量的增强可能会产生正反馈，进一步放大这种状态变化。本项目考察了河床和浮冰湖与假定的永久冻土和气候的相互作用和反馈的范围和动态。遥感、实地监测和地球物理测量、实验和物理模型的结合用于分离过程、量化相互作用和项目变化。该项目的研究结果将与当地村庄的生存和石油工业的供水有关，并与全球研究永久冻土融化和北极气候变化的科学家有关。

Shallow lakes and ponds may cover up to 40 percent of the land surface in Arctic lowland regions. Many of these water bodies traditionally freeze solid during the winter, preserving sub-lake permafrost and keeping soil carbon stocks immobile at depth. Slightly deeper lakes maintain some liquid water beneath floating ice, causing deep thaw zones in otherwise continuous permafrost. Evidence suggests that thinner ice growth in response to warmer, snowier winters is pushing many bedfast ice lakes to floating ice regimes. If such a regime shift becomes pervasive across lake-rich landscapes, resulting permafrost thaw and enhanced moisture and heat flux could generate positive feedbacks, further amplifying this regime change. This project examines the extent and dynamics of bedfast and floating ice lakes in relation to hypothesized interactions and feedback with permafrost and climate. A combination of remote sensing, field monitoring and geophysical measurements, experiments and physical models are used to isolate processes, quantify interactions and project changes. Project findings will be relevant locally for native village subsistence and for water supply to the petroleum industry, and globally for scientists studying permafrost thaw and Arctic climate change.