A Test of Borehole Paleoclimatology as a Method to Quantify Radiative Climate Forcing

该合同将测试从井眼温度-深度（T-z）剖面重建的地表温度（GST）、地表空气温度（SAT）、土壤温度和太阳辐射之间的一致性。它将解决将人为温室气体强迫与自然辐射强迫分离的关键挑战。这一挑战是困难的，因为气象和多代理温度记录中的复合温度信号不能直接分解为辐射强迫分量。然而，由于辐射加热和地面与空气之间的热交换直接控制地面温度，因此，在记录太阳辐射、土壤和空气温度的时间段内进行钻孔T-z测量的时间序列将能够将储存在地下的热能与这些量进行比较。如果能源储存、太阳辐射、GST、SAT和多代理温度数据之间的一致性可以在一到二十年的尺度上被识别出来，那么综合过去几个世纪的这些数据可能使我们能够分别确定气候变化的人为强迫和自然强迫。本项目所需资料包括：(1) 20世纪70年代至今加拿大和美国用于古气候和热流研究的钻孔的新T-z测量数据；(2)美国历史气候学网、高平原区域气候中心自动天气数据网和加拿大环境部的气象数据；(3)钻孔观测期间选定钻孔和气象站点地表覆盖状况的直接和遥感数据。该项目解决了几个相关问题：GST、SAT、土壤温度和太阳辐射之间的一致性是什么？钻孔地点和气候站的小气候变化是否影响温度趋势？如果获得了良好的相干性，那么在两次T-z测量之间的时间内，储存在地下的热能和辐射强迫之间的相干性是否可以延伸到过去的几个世纪？最后，该奖项将有助于评估北美从中纬度地区到极地地区的气候变化幅度，以确定观测到的趋势是否支持一般环流模式的预测。这是一个新兴的研究领域，具有广泛的应用前景和巨大的潜在科学回报，将现代和古气候研究相结合。本项目所需资料包括：(1) 20世纪70年代至今加拿大和美国用于古气候和热流研究的钻孔的新T-z测量数据；(2)美国历史气候学网、高平原区域气候中心自动天气数据网和加拿大环境部的气象数据；(3)钻孔观测期间选定钻孔和气象站点地表覆盖状况的直接和遥感数据。该项目解决了四个相关问题：GST、SAT、土壤温度和太阳辐射之间的一致性是什么？钻孔地点和气候站的小气候变化是否影响温度趋势？如果获得了良好的相干性，那么在两次T-z测量之间的时间内，储存在地下的热能和辐射强迫之间的相干性是否可以延伸到过去的几个世纪？最后，该奖项将评估北美从中纬度到极地地区的气候变化幅度，以确定观测到的趋势是否支持一般环流模式的预测。这是一个新兴的研究领域，具有广泛的应用前景和巨大的潜在科学回报，将现代和古气候研究相结合。

This award will test coherence between ground surface temperatures (GST) reconstructed from borehole temperature - depth (T-z) profiles, surface air temperatures (SAT), soil temperatures, and solar radiation. It will address the critical challenge of separation of forcing by anthropogenic greenhouse gases from natural radiative forcing. This challenge is difficult because the composite temperature signal in the meteorological and multi-proxy temperature records cannot be directly resolved into radiative forcing components. However, since radiative heating and heat exchange between the ground and the air directly control the ground surface temperature, a time-series of borehole T-z measurements spanning time periods when solar radiation, soil, and air temperatures have been recorded will enable comparison of the thermal energy stored in the ground to these quantities. If coherence between energy storage, solar radiation, GST, SAT and multi-proxy temperature data can be discerned for a one or two decade scale, synthesis of these data over the past several centuries may enable us to separately determine the anthropogenic and natural forcing of climate change. The data required for this project include: (1) New T-z measurements in boreholes previously used in paleoclimate and heat flow research in Canada and the United States from the 1970's to the present, (2) Meteorological data from the US Historical Climatology Network, the Automated Weather Data Network of the High Plains Regional Climate Center, and Environment Canada, and (3) Direct and remotely sensed data on surface land cover conditions at selected borehole and meteorological sites for the periods between borehole observations. The project addresses several related questions: What is the coherence between the GST, SAT, soil temperatures and solar radiation? Have microclimate changes at borehole sites and climate stations affected temperature trends? If good coherence is obtained, can the coherence between thermal energy stored in the ground and radiative forcing during the time between T-z measurements be extended several centuries into the past? Finally, this award will help assess the magnitude of climate change in North America from middle latitudes to polar regions to determine if the trends observed support the predictions of general circulation models.This research is in a new and emerging field with broad application and significant potential scientific payoff in integrating modern day and paleo-climate research. The data required for this project include: (1) New T-z measurements in boreholes previously used in paleoclimate and heat flow research in Canada and the United States from the 1970's to the present, (2) Meteorological data from the US Historical Climatology Network, the Automated Weather Data Network of the High Plains Regional Climate Center, and Environment Canada, and (3) Direct and remotely sensed data on surface land cover conditions at selected borehole and meteorological sites for the periods between borehole observations.The project addresses four related questions: What is the coherence between the GST, SAT, soil temperatures and solar radiation? Have microclimate changes at borehole sites and climate stations affected temperature trends? If good coherence is obtained, can the coherence between thermal energy stored in the ground and radiative forcing during the time between T-z measurements be extended several centuries into the past? Finally, this award will assess the magnitude of climate change in North America from middle latitudes to polar regions to determine if the trends observed support the predictions of general circulation models.This research is in a new and emerging field with broad application and significant potential scientific payoff in integrating modern day and paleo-climate research.