Collaborative Research:Extracting Multi-century Low-latitude Sea Surface Temperatures from Coral Skeletons Using Replicated Records of Annual Growth: Method Refinement&Application

合作研究：利用年度生长的复制记录从珊瑚骨骼中提取多个世纪的低纬度海面温度：方法改进

• 批准号: 1211106
• 负责人: Braddock Linsley
• 金额: $ 7.92万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1211106&HistoricalAwards=false
• 关键词: Collaborative; Research; Extracting; Multi; century

Proxy reconstructions of global temperatures over the past 1000 years provide a context for understanding recent warming trends and allow better estimates of the contribution of anthropogenic (greenhouse gas) forcing to global climate change. Data compiled mostly from high latitude tree ring records suggest that the late 20th century was the warmest period of the last millennium. Nevertheless, the uncertainties associated with these estimates are significant, especially during the period known as the Medieval Warming which ended ~700 years ago. Temperature changes at the earth?s surface follow most closely those of the global tropics, which are 75% ocean; yet few datasets that span the last 1000 years exist from the low latitude oceans. In order to improve global temperature reconstructions and to reduce uncertainties, well-replicated records of sea surface temperature (SST) from the low-latitude oceans are urgently needed. Massive long-lived corals, which accrete calcium carbonate skeleton in annual bands like growth rings on a tree, have the potential to provide this information. The PIs have recently applied a method of reconstructing annual SST that takes advantage of the demonstrated relationship between the skeletal growth of corals and water temperature. In multiple records generated from 3 coral species, coral growth captures between 50-60% of the SST variability in the instrumental record, on interannual and longer timescales. Applying the method to a ~440-year long slow-growing coral collected from the Bahamas suggests that SSTs were within error of modern ~ AD1550, that Little Ice Age SSTs were about 1ºC cooler than today and that there is a strong anthropogenic signal in the SSTs of the last 50 years. The PIs will build on this initial work, focusing on refining the method of extracting SST from coral growth records and applying it to generate multi-century long proxy SST records for the low-latitude Atlantic and Pacific Oceans. Data acquisition by 3-D CAT scanning of intact coral cores is relatively rapid and inexpensive, enabling generation of many records of varying lengths from multiple colonies at each site, and, using techniques applied in dendrochronology, provide enough data to provide realistic error estimates on reconstructed SSTs. Funding will support 3 PIs, a post-doctoral research scientist, a PhD student, and research experience for an undergraduate.

在过去的1000年中，全球温度的代理重建为了解最近的变暖趋势提供了一个背景，并可以更好地估计人为（温室气）对全球气候变化的贡献。数据主要来自高纬度树环记录，这表明20世纪后期是上一个千年中最温暖的时期。然而，与这些估计相关的不确定性很重要，尤其是在700年前结束的中世纪变暖的时期。地球表面的温度变化最遵循全球热带地区的温度变化，海洋为75％。然而，从低纬度海洋中，很少有跨越1000年的数据集存在。为了改善全球温度的重建并减少不确定性，迫切需要从低纬度海洋的海面温度（SST）进行良好的记录。大量的长寿命珊瑚（在树上的生长环）中，碳酸钙骨骨架具有碳酸钙骨架，具有提供此信息的潜力。 PI最近采用了一种重建年度SST的方法，该方法利用了珊瑚的骨骼生长与水温之间的相关关系。在从3种珊瑚物种产生的多个记录中，珊瑚生长捕获了仪器记录中SST变异性的50-60％，在年际和更长的时间尺度上。将该方法应用于巴哈马收集的〜440年长的慢增长珊瑚，这表明SST在现代〜AD1550的误差范围内，几乎没有冰河时代的SST比今天凉爽1ºC，并且在过去50年的SST中存在强烈的人为信号。 PI将基于这项最初的工作，重点是完善从珊瑚增长记录中提取SST的方法，并将其应用于低纬度大西洋和太平洋的跨世纪长代理SST记录。通过3-D CAT扫描完整核心核心的数据采集相对较快且廉价，从而能够生成许多从每个地点的多个菌落中不同长度的记录，并且使用在树突年代学中应用的技术，可以提供足够的数据，提供足够的数据以在SST上提供现实的错误估计。资金将支持3 PI，博士后科学家，博士生和本科生的研究经验。