Radiocarbon Profiles and Rapid Climate Change in the Deep North Atlantic: Deep Sea Corals from the Glacial to the Holocene

摘要：根据该奖项，PI建议使用来自深海珊瑚的U系列和14 C日期来直接测量过去深海的14 C/12 C比率（14 C）。 这应该能说明大西洋翻转环流强度的历史，这是理解气候变化的一个关键因素。PI从新英格兰海山收集了一套珊瑚样本，深度约为1100 - 2500米。在收集中有超过3,700个我们的主要物种，D。cristagalli和超过60公斤的另一个物种，Solenosmilia sp。从前100个U系列日期很明显，大约30%的收集覆盖了放射性碳年龄窗口。从一个关键的深度间隔，并跨越末次冰期到全新世早期的许多样本，建议的结果将是多个配置文件的14 C从过去的北大西洋。 此外，在单一珊瑚骨骼内进行高分辨率14 C年龄取样可以限制深水质量转变的速率和时间。 独立的U系列年龄控制允许这些日期明确的水团重组与任何其他日期明确的气候档案进行比较。将制作两类数据集：年龄相同但深度不同的许多珊瑚的剖面图，以及同一深度年龄重叠的若干珊瑚的时间序列。这两种类型的.14C重建将与快速气候变化的冰芯记录和包含深循环速率和碳循环变化信息的大气.14C记录进行比较。通过冰芯（和石笋）的比较，PI将确定快速气候期间深海和大气的相位。

Abstract: Under this award the PI proposes to use coupled U-series and 14C dates from deep-sea corals to directly measure the 14C/12C ratio (14C) of the past deep ocean. This should give an indication of the history of the strength of Atlantic overturning circulation which is a critical element in understanding climate change. The PI has collected a suite of coral samples from the New England Seamounts over a depth range of ~1,100-2,500 meters. In the collection there are over 3,700 individual samples of our main species, D. cristagalli, and over 60 kg of another species, Solenosmilia sp. From the first 100 U-series dates it is clear that about 30% of the collection covers the radiocarbon age window. With many samples from a key depth interval, and spanning the LGM to the early Holocene, the proposal outcome will be multiple profiles of 14C from the past North Atlantic. In addition, high-resolution 14C age sampling within single coral skeletons can constrain the rates and timing of deep-water mass transitions. Independent U-series age control allows these well-dated water mass reorganizations to be compared to any other well dated climate archives. Two types of data sets will be produced; profiles from many corals with the same age but different depths, and time-series from several corals of overlapping age at the same depth. These two types of .14C reconstructions will be compared to ice core records of rapid climate change and records of atmospheric .14C that contain both deep circulation rate and carbon cycle change information. From the ice core (and stalagmite) comparisons the PI will determine the phasing of the deep ocean and the atmosphere during rapid climate.