COLLABORATIVE RESEARCH: Spatial and Temporal Influences of Thermokarst Features

合作研究：热喀斯特特征的时空影响

• 批准号: 0806254
• 负责人: George Kling
• 金额: $ 33.6万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0806254&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; Spatial; Temporal; Influences

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.

最近的国际研究总结清楚地记录了北极气候变暖的过去和未来程度。这些总结表明，未来气温上升将伴随着降水的增加，主要是降雨：整个北极地区在冬季和秋季将增加20%，沿海地区将增加30%。这些气候变化将对北极系统产生重要影响。对这项研究直接感兴趣的是，气候变暖可能会促进永久冻土的退化和融化。以前的冻土可能会因降雨量增加而进一步不稳定，从而导致山坡热岩溶破坏。最近的研究证明，热岩溶破坏现象比比皆是，而且似乎在东部北坡的图利克湖周围和阿拉斯加西部的诺亚塔克河流域变得更加频繁。热岩溶破坏的广泛和长期增加可能会对北极源头地区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关于热岩溶失败如何影响北极景观的结构和功能的假说。它将侧重于植被的组成，土壤养分的分配和处理，以及向河流和湖泊生态系统输出沉积物和养分。在这个山坡尺度上获得的结果将与在景观尺度上观察到的模式联系起来，以检验关于北极山脚下热岩溶破坏的空间分布的假设。了解这些相互作用是很重要的，因为陆面过程的变化和热岩溶失败的形成的最大潜在影响可能是通过能量、反照率、水和微量气体交换对气候系统的反馈。这项研究旨在量化气候学、山坡水文学、地貌学、地球气象学、植被群落生态学、土壤养分动力学、微生物生态学、痕量气体动力学和水生生态之间的联系。它将采用实地试验、遥感和模拟建模相结合的方法来量化这些关系。