Heat-Transfer Processes in Discontinuous Permafrost Regions

高纬度地区气候变暖的可能性引发了人们对北极大片地区永久冻土广泛融化前景的日益担忧。然而，永久冻土融化的动力学还没有被完全理解。将传导性热传递作为主要机制的长期观点受到了新理论的挑战，新理论认为非传导性热传递在永久冻土的冻结和融化中也起着重要作用。该项目将评估这些机制和其他可能的过程对阿拉斯加中部各种环境下永久冻土动态的影响程度。将在一组成对的永久冻土和非永久冻土地点收集各种不同土壤、冰雪、温度和湿度条件的测量数据。这些数据将用于分析这些不同变量之间的关系，并测试永久冻土内热传递的不同模型。该项目将提供有关永久冻土区和非永久冻土区土壤内部和土壤上方条件的宝贵新数据，并将对有关影响永久冻土区稳定性的传热机制的相互竞争的假设进行有效测试。除了提供关于永久冻土动力学的新见解外，该项目还将通过在恶劣环境中测试新仪器的功效来做出方法上的贡献。

The possibility of climatic warming in high-latitude zones has fueled growing concern about prospects for widespread melting of permafrost across large areas of the Arctic. The dynamics by which permafrost melts are not fully understood, however. Longstanding views that held conductive heat transfer as the primary mechanism have been challenged by new theories that hold that nonconductive heat transfer also plays an important role in the freezing and thawing of permafrost. This project will assess the degree to which each of these mechanisms and other possible processes affects permafrost dynamics in a variety of settings in central Alaska. Measurements of a variety of different soil, snow and ice, temperature, and moisture conditions will be collected at a set of paired permafrost and non-permafrost sites. These data will be used to analyze relationships among these different variables and to test different models of heat transfer within permafrost. This project will provide valuable new data on conditions within and immediately above the soil in permafrost and non-permafrost regions, and it will provide an effective test of competing hypotheses regarding heat transfer mechanisms that affect the stability of permafrost. In addition to contributing to new insights about permafrost dynamics, this project also will make methodological contributions by testing the efficacy of new instruments in harsh environments.