Assessing multi-site δ18O-climate calibrations of the coralline alga Clathromorphum across the high-latitude Northern Hemisphere
Assessing multi-site δ18O-climate calibrations of the coralline alga Clathromorphum across the high-latitude Northern Hemisphere
复制标题
评估北半球高纬度珊瑚藻 Clathromorphum 的多地点 δ18O 气候校准
DOI：
10.1016/j.gca.2016.08.023
复制
发表时间：
2016
影响因子：
5
通讯作者：
K. Johnson
中科院分区：
文献类型：
--
作者：
J. Ng;B. Williams;D. Thompson;Chloe Mayne;J. Halfar;E. Edinger;K. Johnson
增加气候代用记录的数量和更精确地解释代用数据对于改善高纬度地区未来气候的预测至关重要，因为在高纬度地区，内部反馈放大了变暖，建立的高分辨率气候档案特别稀少。正在开发结壳珊瑚藻作为中高纬度海洋气候档案。这些长寿的藻类形成了一个坚实的高镁方解石骨架，每年的生长带类似于树木和热带珊瑚。藻类骨骼的氧同位素比值（δ 18 Oalg）记录了当地的环境和气候因素，本文利用两种珊瑚藻Clathromorphum的δ ~（18）Oalg与气候的关系进行了研究。Clathromorphum广泛分布于寒温带和温带，在寒温带和温带都有分布。从温带北大西洋和太平洋到北冰洋，最近产生了许多长达650年的气候重建。在这项研究中，我们将四个样本的δ 18 O校准为网格温度和盐度数据，后者是海水δ 18 O的代表。这些标本是从高纬度北方半球的各种藻类生长环境中收集的：两个标本来自阿留申群岛，一个来自加拿大北极地区，一个来自缅因州湾。冬季低温和日照限制了藻类在其骨骼的δ 18 O中记录当地气候的月份;因此，我们通过将每个站点的月度温度和盐度异常与年度δ 18 Oalganomalies相关联来确定这些响应季节。然后，我们对与δ 18 Oalg回归显著相关（95%置信区间）的数月网格数据进行平均。虽然气候信号的时间和性质因地点而异，但我们发现δ 18 Oalg与三个地点响应季节平均的温度或盐度之间存在显着关系。四个地点之间的局部气候变化提供了一个物理解释校准差异，加剧了代理年表，生物变异性，时间覆盖范围和稀疏的历史气候数据所产生的不确定性。本研究为利用珊瑚藻δ 18 O重建高纬度海洋气候模式和发展藻类代用系统模式迈出了重要的一步。
An increased number of climate proxy records and more refined interpretation of proxy data are crucial to improve projections of future climate at high latitudes, where internal feedbacks amplify warming and established high-resolution climate archives are especially sparse. Encrusting coralline algae are being developed as a mid- to high-latitude marine climate archive. These long-lived algae form a solid high-Mg calcite skeleton with annual growth bands similar to those of trees and tropical corals. The oxygen isotope ratio of the algal skeleton (δ18Oalg) records local environmental and climatic factors, notably sea surface temperature and seawater δ18O.Here we assess the δ18Oalg–climate relationship in diverse environments across the algal habitat range utilizing two species of coralline algae from the genusClathromorphum.Clathromorphumis widely distributed from the cold-temperate North Atlantic and Pacific to the Arctic Ocean and has recently yielded numerous climate reconstructions of up to 650 years in length. In this study, we calibrate δ18Oalgof four specimens to gridded temperature and salinity data, the latter a proxy for seawater δ18O. These specimens were collected from a variety of algal growth environments across the high-latitude Northern Hemisphere: two specimens from the Aleutian Archipelago, one from the Canadian Arctic, and one from the Gulf of Maine. Low winter temperatures and insolation restrict the months when algae record local climate in the δ18O of their skeletons; we therefore determine these response seasons by correlating monthly temperature and salinity anomalies with annual δ18Oalganomalies at each site. We then average gridded data over months that correlate significantly (95% confidence interval) for regression with δ18Oalg. While the timing and nature of the climate signal vary across sites, we find significant relationships between δ18Oalgand either temperature or salinity averaged over the response season at three sites. Variation in local climatology among the four sites provides a physical explanation for calibration differences, compounded by uncertainties stemming from the proxy chronology, biological variability, temporal coverage, and sparse historical climate data. This work takes an essential step toward reconstructing high-latitude marine climate patterns with coralline algal δ18O and developing algae proxy system models.