COLLABORATIVE RESEARCH: Spatial and Temporal Influences of Thermokarst Failures on Arctic Surface Processes

最近的国际研究摘要清楚地记录了北极过去和未来气候变暖的程度。这些总结表明，在未来，气温上升将伴随着降水的增加，主要是降雨：整个北极地区的降水量增加20%，冬季和秋季沿海地区的降水量增加30%。这些气候变化将对北极系统产生重要影响。这项研究的直接利益是变暖将促进永久冻土退化和融化的可能性。以前冻结的土壤可能会因降水量增加而进一步破坏稳定，导致山坡热岩溶破坏。最近的工作证明，热岩溶故障是丰富的，似乎已经变得越来越多的图里克湖周围的北坡东部和西部的诺塔克河流域在阿拉斯加。广泛和长期增加的热岩溶故障的发生率可能会对北极河源景观的结构和功能产生重要影响。这项研究将使用系统的方法来解决如何热岩溶故障影响北极景观的结构和功能的假设。它将侧重于植被的组成、土壤养分的分布和处理，以及沉积物和养分向河流和湖泊生态系统的输出。在这个山坡规模获得的结果将被连接到在景观尺度上观察到的模式，以测试在北极山麓热岩溶故障的空间分布的假设。了解这些相互作用是很重要的，因为改变地表过程和形成热岩溶破坏的最大潜在影响可能是通过能量、水分、水和微量气体交换反馈到气候系统。本研究旨在量化气候学、山坡水文学、地貌学、冻土学、植被群落生态学、土壤养分动态学、微生物生态学、微量气体动力学和水生生态学它将采用现场实验，遥感和模拟建模相结合的方式来量化这些关系。

Recent summaries of international research clearly document the past and future extent of climate warming in the Arctic. These summaries suggest that in the future, rising temperatures will be accompanied by increased precipitation, mostly as rain: 20% more over the Arctic as a whole and up to 30% more in coastal areas during the winter and autumn. These climate changes will have important impacts on Arctic Systems. Of direct interest to this research is the likelihood that warming will promote permafrost degradation and thaw. Formerly frozen soils may be further destabilized by increased precipitation, leading to hillslope thermokarst failures. Recent work has documented that thermokarst failures are abundant and appear to have become more numerous around Toolik Lake on the eastern North Slope and in the western Noatak River basin in Alaska. A widespread and long-term increase in the incidence of thermokarst failures may have important impacts on the structure and function of arctic headwater landscapes. This research will use a systems approach to address hypotheses about how thermokarst failures influence the structure and function of the arctic landscape. It will focus on the composition of vegetation, the distribution and processing of soil nutrients, and exports of sediments and nutrients to stream and lake ecosystems. Results obtained at this hillslope scale will be linked to patterns observed at the landscape scale to test hypotheses about the spatial distribution of thermokarst failures in the arctic foothills. It is important to understand these interactions because perhaps the greatest potential impacts of changing land surface processes and formation of thermokarst failures are feedbacks to the climate system through energy, albedo, water, and trace gas exchange.This research is designed to quantify linkages among climatology, hillslope hydrology, geomorphology, geocryology, community ecology of vegetation, soil nutrient dynamics, microbial ecology, trace gas dynamics, and aquatic ecology. It will employ a combination of field experimentation, remote sensing, and simulation modeling as a means to quantify these relationships.