Collaborative Research: Remote Observations of Ice Sheet Surface Temperature: Toward Multi-Proxy Reconstruction of Antarctic Climate Variability

合作研究：冰盖表面温度的远程观测：南极气候变化的多代理重建

• 批准号: 0126161
• 负责人: Dale Winebrenner
• 金额: $ 33.26万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2005-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0126161&HistoricalAwards=false
• 关键词: Collaborative; Research; Remote; Observations; Ice

This project will develop spatially extended and statistically reliable estimates of Antarctic surface temperature variations over the past several centuries, using a multi-proxy calibration/verification approach that combines the climate signal in ice core, satellite remote sensing, and weather station data. Antarctica has been problematic from the point of view of large-scale paleoclimate reconstruction because of the paucity of long-term instrumental data, and the relatively low resolution of most ice cores. Several new developments, particularly the network of shallow (~100 meter) ice cores from the ongoing International Trans-Antarctic Scientific Expedition (ITASE) project will yield broad spatial coverage of annually resolved ice core physical properties, chemistry, and stable isotope data over more than a hundred years. Second, there are now over twenty years of microwave and infrared brightness temperatures available from satellites covering virtually all of Antarctica with seasonally resolved information that has been demonstrated to record the ice surface/near surface temperature with very reasonable precision and accuracy. Finally, higher quality microwave emission data from Advanced Microwave Scanning Radiometers (AMSR) with much finer spatial resolution and radiometric fidelity than those from previous sources will offer an improved view of longer term mean temperatures in Antarctica.The 40-year instrumental record and the shorter but spatially more comprehensive Automatic Weather Station network will be combined with seasonally-resolved 37-gigahertz satellite-based ice surface temperature estimates to reconstruct Antarctic-wide temperature patterns during the past forty years. The sparser Antarctic instrumental surface temperature data available back nearly to the beginning of the century will be added for longer-term, though quite spatially-restricted, cross-validation of these reconstructions. This cross-validation procedure has been used successfully with roughly century-long instrumental records at locations primarily in the Northern Hemisphere. The longer time scale will be approached through a cross-validation of the proxy-based pre-20th century surface temperature reconstructions using information on thermal emission from deeper in the firn that is contained in low-frequency passive microwave satellite measurements. The low-frequency estimates, supplemented by borehole thermometry, will provide important independent verification of the long-term averages of the annual surfac

该项目将利用结合冰芯、卫星遥感和气象站数据中的气候信号的多代理校准/核实方法，对过去几个世纪南极表面温度变化进行空间扩展和统计上可靠的估计。从大规模古气候重建的角度来看，南极洲一直是个问题，因为缺乏长期的仪器数据，而且大多数冰芯的分辨率相对较低。一些新的发展，特别是正在进行的国际跨南极科学考察(ITASE)项目的浅(约100米)冰芯网络，将产生100多年来每年可分辨的冰芯物理性质、化学和稳定同位素数据的广泛空间覆盖。其次，现在有超过20年的微波和红外亮度温度，卫星几乎覆盖了整个南极洲，并具有季节性分辨率的信息，已证明可以非常精确和准确地记录冰面/近表面温度。最后，来自先进微波扫描辐射计(AMSR)的更高质量的微波辐射数据具有比以前来源更精细的空间分辨率和辐射保真度，将提供更好的南极长期平均温度的视图。40年的仪器记录和较短但空间上更全面的自动气象站网络将与季节性分辨率的37千兆赫卫星冰面温度估计相结合，重建过去40年南极范围内的温度模式。几乎可以追溯到本世纪初的更稀疏的南极仪器表面温度数据将被添加到这些重建的更长期的交叉验证中，尽管空间上有很大的限制。这种交叉验证程序已经在主要位于北半球的地点成功地用于大约一个世纪的仪器记录。更长的时间尺度将通过交叉验证20世纪以前基于代理的地表温度重建，利用低频被动微波卫星测量中包含的关于积雪深处热辐射的信息来实现。低频估计加上钻孔测温，将对年地表的长期平均值提供重要的独立核实