COLLABORATIVE RESEARCH: An 18 O Paleotemperature Curve for the North Atlantic for the Last 1000 Years, From Annual Growth Bands of the Bivalve Arctica islandica

小行星9709895 这项研究将产生一个海洋温度记录的北方北大西洋涵盖了过去1000年，根据稳定的氧同位素分析的年度增长带的长寿的双壳类Arctica islandica。 乐队从时期CA。500-1000年B. P.的年代测定将采用放射性碳分析法，而100-500年B. P.的年代测定将采用天冬氨酸外消旋法，这将比放射性碳对这一时期的测定提供更高的精确度。 过去100年的18 O年记录已经由北极星的活体采集建立起来（魏德曼和琼斯，在准备中）。 这项研究将利用从南图克特浅滩地区表层沉积物中挖掘出的亚化石贝壳进行。 这一外大陆架区域很浅，足以提供上层海洋沃茨的温度记录，但又远离海岸，不受大陆淡水输入的影响。 该地点的另一个特点是，它是从前南图克特灯塔获得的特别长的温度仪器记录的地点，目前是NOAA长期天气监测地点。 一个时间序列。将选择25个髋臼杯进行分析，这些髋臼杯跨越相关年龄范围，每个髋臼杯均包含50年的生长记录。 本研究的第二个主要目标是评估交叉匹配的带宽变化的个人之间构建一个年度时间序列，类似于树木年轮系列。 这有可能产生北大西洋近几个世纪以来环境变化的连续年度记录。 与陆地环境相比，海洋环境的长时间（100年）高分辨率记录很少，而且在高纬度海洋区域基本上不存在。 缺乏适当的海洋温度记录限制了我们对大气和海洋气候变化之间联系的理解。 这些信息对于了解最近气候变化的性质和原因至关重要。 这些变化包括中世纪暖期、小冰期和世纪变暖趋势的长期（世纪尺度）变化，以及北大西洋涛动等短期（十年尺度）波动。 在这项研究中首次提出的从软体动物壳中提取此类记录的方法也可用于从其他海洋区域获得古气候记录。 将收集的贝壳生长带的1 000年时间序列将作为海洋地球化学记录的档案，并将提供给其他工作人员进行其他类型的分析。 该研究是一个由G.他是华盛顿卡内基研究所的好朋友。伍兹霍尔海洋研究所的魏德曼。

9709895 Goodfriend This study will produce an ocean temperature record for the northern North Atlantic covering the last 1000 years, based on stable oxygen isotope analysis of annual growth bands of the long-lived bivalve Arctica islandica. Bands from the period ca. 500-1000 yr B.P. will be dated by radiocarbon analysis, whereas those from 100-500 yr B.P. will be dated by aspartic acid racemization which will provide significantly better precision than radiocarbon for this period. An annual 18O record for the last 100 yr has already been constructed from live-collected Arctica (Weidman and Jones, in prep.). The study will be carried out using subfossil shells dredged from surface sediments in the Nantucket Shoals region. This outer continental shelf area is shallow enough to provide a temperature record of upper ocean waters but far enough off shore to be away from the influence of continental freshwater inputs. The site is further distinguished by being the location of a particularly long instrumental record of temperatures obtained from the former Nantucket Lightship and is currently a NOAA long-term weather monitoring site. A time series of ca. 25 shells, spanning the relevant age range and each containing a record of 50 years growth, will be selected for analysis. The second primary goal of this study is to evaluate cross-matching of band width variations among individuals to construct an annual time series, analogous to tree ring series. This has the potential to produce a continuous annual record of environmental changes in the North Atlantic over recent centuries. Long (100 yr), high-resolution records of marine environments are rare, in contrast to terrestrial environments, and are largely absent for higher-latitude ocean regions. This paucity of suitable ocean temperature records restricts our understanding of linkages between atmospheric and oceanic climate variations. Such information is critical to understanding the nature and causes of recent climate changes. The se include the long-term (century scale) variations of the Medieval Warm Period, the Little Ice Age, and the warming trend of the 20th century, which have been documented from terrestrial records, as well as shorter-term (decadal scale) fluctuations such as the North Atlantic Oscillation. The methods that are brought together in this study for the first time to extract such records from mollusk shells can also be used to obtain paleoclimatic records from other ocean regions. The 1000-year time series of shell growth bands that will be assembled will serve as an archive of the marine geochemical record and will be made available to other workers for other types of analyses. The proposed study constitutes a collaborative research project between G. Goodfriend at the Carnegie Institution of Washington and C. Weidman at the Woods Hole Oceanographic Institution.