Borehole Climatology: Continental Energy and Climate Change

钻孔气候学：大陆能源与气候变化

• 批准号: RGPIN-2016-05156
• 负责人: Beltrami, Hugo
• 金额: $ 2.11万
• 依托单位: St. Francis Xavier University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=683020
• 关键词: Borehole; Climatology; Continental; Energy; Climate

We are witnesses to increased research about the climate system stimulated by concerns about projections of a warmer Earth. However, ascertaining climate models' projections requires that they be validated with the climate of the past. Only by properly simulating paleoclimate, will a model inspire confidence in its projections. In this avenue, underground temperature data have contributed significantly to our understanding of the climate of the last millennium. Climate reconstructions from these data assume that surface air temperatures are coupled to ground surface temperatures, and the latter propagate to the subsurface by thermal diffusion superimposing on the background steady-state geothermal field. That is, if the temperature at the Earth's surface changes, then a quantity of heat will be gained (warming) or lost (cooling) by the ground; these changes in the energy balance at the surface propagate and are recorded underground as perturbations to the background thermal regime. Analysis of these underground anomalies provides the base of the geothermal method of paleoclimate reconstruction. Climate reconstructions from borehole climatology are unique; their inferences are a measure of long-term climate, independent from meteorological records. This area of research has been the focus of my work for the last few years because of the great potential to shed light on the understanding of climatic change in its natural state. Results from the research program I propose will allow a more complete understanding of the heat transfer regime at the atmosphere-ground interface. My long-term objectives are to characterize the heat transfer regime from the atmospheric boundary layer to the first few hundred meters of the Earth's crust. Such characterization would be very useful for incorporation into climate models to study the climate system; in particular, to understanding the evolution of permafrost. Thermal data from the subsurface are fundamental to understanding the energy balance at the Earth's surface and also provide long-term boundary conditions at the ground surface for climate models. Graduate students will work on adapting the latest version of the Community Land Model - CLM4, to extend its bottom boundary placement to allow the use underground temperatures to understand the changes in the ground surface energy balance and thus the energy partition at the air-ground interface at century and millennia time scales. We intent to perform a millennium-scale ensemble simulation of a global climate model with a fully coupled continental component. In order to use the continental heat storage as a measure of performance of land surface models, we will continue gathering additional geothermal data from underrepresented continental areas of the world; for example, Chile, Argentina and Brazil. I plan to continue involving PhD and MSc students throughout all aspects of this project.

我们见证了对气候系统研究的增加，这是由于对地球变暖的预测感到担忧。然而，要确定气候模型的预测，需要用过去的气候来验证它们。只有适当地模拟古气候，模型才能激发人们对其预测的信心。在这方面，地下温度数据对我们了解上个千年的气候有很大贡献。由这些数据重建的气候假设地表气温与地面温度耦合，后者通过热扩散叠加在背景稳态地热场上传播到次表层。也就是说，如果地球表面的温度发生变化，那么地面将获得(变暖)或失去(冷却)一定量的热量；这些地表能量平衡的变化会传播，并记录在地下，作为对背景热状况的扰动。这些地下异常的分析为地热法重建古气候奠定了基础。根据钻孔气候学重建的气候是独一无二的；它们的推断是对长期气候的衡量，独立于气象记录。这一领域的研究一直是我过去几年工作的重点，因为它具有阐明气候变化在其自然状态下的巨大潜力。我提出的研究计划的结果将使我们能够更全面地了解大气-地面界面的热传递状况。我的长期目标是描述从大气边界层到地壳前几百米的热传递机制。这种特征将非常有助于纳入气候模型来研究气候系统，特别是理解永久冻土的演化。来自地下的热数据是了解地球表面能量平衡的基础，也为气候模型提供了地面的长期边界条件。研究生将致力于适应最新版本的社区陆地模式-CLM4，以扩展其底部边界位置，以允许使用地下温度来了解地面能量平衡的变化，从而了解在世纪和千年时间尺度上空中-地面界面的能量分配。我们打算执行一个具有完全耦合的大陆分量的全球气候模式的千年尺度集合模拟。为了利用大陆储热量作为衡量陆地表面模型性能的指标，我们将继续从世界上代表性较低的大陆地区，例如智利、阿根廷和巴西，收集更多的地热数据。我计划继续让博士生和硕士学生参与到这个项目的各个方面。