Detecting Seasonal through Centennial Variability in Sea Surface Temperatures of the Subtropical North Atlantic

通过北大西洋副热带海面温度的百年变化检测季节性

• 批准号: 0402728
• 负责人: Anne Cohen
• 金额: $ 33.24万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-01 至 2007-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0402728&HistoricalAwards=false
• 关键词: Detecting; Seasonal; through; Centennial; Variability

Under this award the PIs will use large corals heads primarily of the species Diploria labyrinthiformis to reconstruct multicentury long records of SST variability in the western subtropical North Atlantic. This should enable exploration of the ocean's role in climate change on decadal and longer time scales, specifically the North Atlantic Oscillation. The available instrumental record of SST extends back little more than a century. However, biases and sparseness of data render the older part of the SST record unreliable and the demonstrated association between NAO and mid-latitude SST anomalies is based exclusively on data gathered since 1950. The PIs will extend the SST record for the mid-latitude North Atlantic using long-lived brain corals collected on Bermuda, a site well placed to index the subtropical gyre. Three independent paleothermometers ( 18O, Sr/Ca and skeletal growth) will be applied to the skeletons of two massive colonies to construct a 500 year-long multiproxy record of SST variability at seasonal resolution. In addition the PIs will sample, date and analyze four massive non-living colonies already identified as potentially old enough to extend the 500 year-long proxy record back to 1000 AD. This multicentury long record will enable key, unresolved issues in North Atlantic climate to be addressed. In particular, estimates of the sensitivity of the mid-latitude atmosphere to changes in surface boundary conditions requires seasonally-resolved records of SST that span the significant climatic events of the late Holocene. The PIs will examine possible secular changes in SST related to global warming and the connection with the NAO anomaly of the past 30 years. Other key questions relate to the sensitivity of SST to solar forcing and volcanic eruptions, and the existence of decadal through centennial-scale periodicity in surface ocean conditions.

根据该奖项，PIS将使用大型珊瑚头部，主要是迷宫珊瑚，重建北大西洋西亚热带SST变异性的多中心长期记录。这应该能够在十年和更长的时间尺度上探索海洋在气候变化中的作用，特别是北大西洋涛动。SST的现有仪器记录可以追溯到一个多世纪以前。然而，数据的偏差和稀疏性使SST记录的较老部分变得不可靠，NAO和中纬度SST异常之间所证明的联系完全基于1950年以来收集的数据。PI将使用在百慕大收集的长寿脑珊瑚来延长北大西洋中纬度地区的SST记录，百慕大是一个非常适合为副热带环流编制索引的地点。三个独立的古温度计(18O、锶/钙和骨骼生长)将应用于两个大型殖民地的骨骼，以建立一个长达500年的季节分辨率SST变率的多代理记录。此外，PI将对四个巨大的非生命殖民地进行采样、日期测定和分析，这些殖民地已经被确定为可能足够古老，可以将长达500年的代理记录追溯到公元1000年。这一多中心的长期记录将使北大西洋气候中的关键、悬而未决的问题得以解决。特别是，估计中纬度大气对地表边界条件变化的敏感度，需要跨越全新世晚期重大气候事件的季节分辨的海温记录。物价指数将研究海温可能与全球变暖有关的长期变化，以及与过去30年NAO异常的联系。其他关键问题涉及SST对太阳强迫和火山喷发的敏感性，以及在表层海洋条件下存在从十年到百年尺度的周期性。