Geothermics and Climate Change: Observatory Mode

在钻孔中测量的温度-深度剖面包含了过去地表温度（GST）变化的时间记录，并为过去几个世纪的气候变化提供了有价值的约束，这是一个超越历史气象记录的关键时期。恢复的GST的最终分辨率取决于地下温度剖面的分辨率，以及人们可以在瞬态原因（即地表温度随时间的变化）和稳态原因（即地形，地形和植被，产热和导热性非均质性，地下水运动等）之间划分温度剖面曲率的置信度。由于井中温度的精确监测和重复测井可以通过隔离温度场的瞬态分量来减少解释的模糊性，因此提出了一种研究井中温度状态及其随时间变化的方案。该项目包括：1)运行实时地面观测站（安装在钻孔现场的气象站），监测气象变量和近地表温度；2)钻孔重复测井，提高稳态温度场的分辨率；3)数据分析，计算现场边界的热物理性质；4)确定gst的时空分辨率。该项目的最终成果和意义是了解地温作为气候变化的记录，并为现有和正在进行的区域钻孔研究提供校准。* * *

97-06559 Chapman Temperature-depth profiles, measured in boreholes, contain a temporal record of past changes in ground surface temperature (GST) and provide valuable constraints on climatic variations over the last few centuries, a critical time period that extends past the historical meteorological record. Ultimate resolution of the recovered GST depends on the resolution of the subsurface temperature profile and the confidence with which one can partition curvature in the temperature profile between transient causes (i.e. changes in surface temperature with time) and steady-state causes (i.e. topography, terrain and vegetation, heat production and thermal conductivity heterogeneities, groundwater movement, etc.). Because precision monitoring and repeat logging of temperatures in wells will reduce the interpretation ambiguity by isolating the transient component of the temperature field, a program of studying borehole thermal regimes and their changes with time is proposed. This project entails 1) operation of a real-time surface observatory (weather station installed at a borehole site) to monitor meteorological variables and near-surface temperature, 2) repeat logging of boreholes to improve the resolution of the steady-state temperature field, 3) data analysis to calculate the in-situ thermal and physical properties of the boundary, and 4) determining the temporal and spatial resolution of GSTs. The final product and significance of this project is an understanding of ground temperature as a record of climatic change and a calibration for existing and ongoing regional borehole studies. ***