Borehole climatology: contributions to the understanding of climate change

钻孔温度剖面（BTP）的数据一直是一个信息来源，大大有助于我们了解百年温度变化。基于BTP的气候重建假设地表气温变化与地表温度变化耦合，并通过热传导传播到次表层。换句话说，如果我们假设地球的上地壳处于热平衡状态，那么上面几公里的温度分布由长期（>1000年）的表面温度和内部热流（在100-105年的尺度上恒定）决定。在这些条件下，对于已知的岩石热性质，温度随深度线性增加。如果地球表面的温度发生变化，那么地面将获得或损失一定量的热量;这些表面能量平衡的变化会传播并记录在地下，作为对平衡热状态的扰动。气候扰动的向下传播取决于岩石的热扩散率（约100%）。10（-6）m2/s），因此地壳表面的前几百米存储了上个千年的综合热特征。由于热传导的性质，表面扰动的幅度呈指数衰减，并且它们的相移作为它们的时间尺度的函数随深度而变化。该过程作为低通滤波器操作，使得低频变化比具有较高频率的变化传播得更深。 通常，扰动一年穿透约20米，100年穿透约150米，一千年穿透约500米，使得地表最近的能量平衡变化保持在浅层地下记录。这些地下扰动的分析提供了基础的钻孔方法来检索过去的温度变化在地面。该提案涉及这一学科面临的最重要的问题，并提出找到解决这些问题的办法，同时将通过对钻孔气候学这些关键领域的研究来培训未来的科学家。

Data from borehole temperature profiles (BTPs) have been one source of information that has significantly contributed to our understanding of centennial temperature changes. Climate reconstructions based on BTPs assume that surface air temperature changes are coupled to ground surface temperature changes and propagate to the subsurface by thermal conduction. In other words, if we assume the Earth's upper crust is at thermal equilibrium, then the temperature distribution in the upper few kilometers is determined by the long-term (>1000 years) surface temperature and the internal heat flow (constant at the 100-105 year scale). Under these conditions, for known thermal properties of the rocks, the temperature increases linearly with depth. If the temperature at the Earth's surface changes, then a quantity of heat will be gained or lost by the ground; these changes in the energy balance at the surface propagate and are recorded underground as perturbations to the equilibrium thermal regime. The downward propagation of the climate disturbance depends on the thermal diffusivity of the rock (ca. 10(-6) m2/s) so that the first few hundred meters of the surface crust store the integrated thermal signature of the last millennium. Due to the nature of heat conduction the amplitude of surface disturbances is exponentially attenuated and their phase shifted with depth as a function of their time scales. The process operates as a low pass filter such that the low-frequency variations propagate deeper than those with higher frequency. Typically, perturbations penetrate about 20 m in a year, 150 m in 100 years and about 500 m in a millennium, such that recent energy balance changes at the surface remain recorded in the shallow subsurface. Analysis of these underground perturbations provides the base of the borehole approach to retrieve past temperature changes at the ground surface. This proposal deals with the most important issues facing this discipline and proposes to find solutions to this issues and at the same time will train future scientists through research on these key areas of borehole climatology.