Collaborative research: Exploring the role of oceanic and atmospheric forcing on Arctic marine climate from newly developed annual shell based records in coastal Norway

海洋学家和古气候学家使用各种代理来研究海洋温度和盐度的过去历史。 其中许多都记录在海洋沉积物中，但沉积率非常小，因此可以从中估计的时间序列只能解决十年或更长时间尺度上发生的变化。 当蛤和其他双壳类动物生长时，它们的壳中会融入它们所生活的水中的地球化学特征。 它们还在壳中留下年轮，就像树木的年轮一样。 通过研究长寿蛤壳中相邻环的化学成分，该项目的主要研究人员 (PI) 希望能够重建挪威北部近海地区近地表水的年度温度和盐度变化。 他们将重点关注中世纪温暖时期（公元1000年至公元1200年）、小冰河时期（公元1200年至公元1850年）和现代时期（公元1850年至今）。 由此产生的温度和盐度变化历史将有助于了解在这些已知的气候变化时期海洋状况如何变化，并有助于验证或约束气候模型。PI？近期目标是重建上个千年内关键气候区间内的年度水文变化，沿具有战略意义的北极岛屿因戈伊和罗尔夫索伊。他们将预测年度海面温度（SST）和海面盐度（SSS）的变化。他们还将建立海洋放射性碳库效应的基线变化。岛屿沿岸的现代近地表海洋学受到挪威海岸流物理特性的影响，而相对较深的水文条件主要取决于大西洋流入。研究地点的试点数据表明，基于贝壳的记录与区域海表温度/次表面海温条件之间存在密切联系。因此，英戈伊和罗尔夫索伊似乎位于研究全新世晚期海洋气候变化的理想地点。已经制定了假设和目标来测试上个千年期间主要气候模式对挪威北部附近区域海洋学的相对影响。目标 1：开发近地表年度贝壳记录（主贝壳年代学和同位素），以重建中世纪气候异常、小冰期和现代气候期间挪威最北海岸的区域水文变化（海温和海温）。目标 2：开发相对深水区(200 m) 过去 100 年的年度贝壳记录（主贝壳年代学和同位素），以描述北大西洋洋流对现场水文学的作用。目标 3：建立自公元 1600 年以来表面海洋放射性碳库效应的十年记录，以估计因戈伊源水贡献的变化。目标 4：估计冬季北大西洋涛动、表面大西洋经向翻转的相对影响区域水文学（因戈伊）和贝壳记录中的环流和大西洋多年代际振荡。将与 Akvaplan-niva（挪威）、爱荷华州立大学（ISU）和贝茨学院（缅因州）的同事建立研究北极海洋气候变化的国际合作伙伴关系。外展、公众参与和结果传播将通过两名 K-12 教师参与实地工作、通过与 K-12 学生的课堂互动、通过 K-12 教师研讨会、通过基于公民的科学（通过与 Ingoy 的挪威本土人互动）以及通过一名将加入 PI 进行一个实地考察的摄影记者来完成。至少一名女博士生和大约五名本科生将得到该项目的支持并参与其中。 PI 将使用该项目中开发的数据和想法，用于 ISU 和贝茨学院有关气候变化、古气候和海洋学的几门课程。 PI Wanamaker 将在艾姆斯公共图书馆举办有关气候变化的公开讲座系列，并继续担任爱德华兹小学科学之夜的联合主席，该活动自 2012 年以来已影响了 1,000 名学生和社区成员。

Oceanographers and paleoclimatologists use various proxies to study the past history of ocean temperature and salinity. Many of these are recorded in the marine sediments, but sedimentation rates are so small that the time series that can be estimated from them only resolve changes that occur on decadal time scales or longer. When clams and other bivalves grow, they incorporate, in their shells, geochemical signatures from the water in which they live. They also lay down growth rings, like tree rings, in their shells. By studying the chemistry of adjacent rings in long-lived clam shells the principal investigators (PIs) of this project expect to be able to reconstruct the annual temperature and salinity variations of near surface waters in a region offshore of northern Norway. They will focus their efforts on the Medieval Warm Period (1000 AD to 1200 AD), the Little Ice Age (1200 AD to 1850 AD), and the modern era (1850 AD until the present). The resultant histories of temperature and salinity variation will be useful for understanding how the ocean conditions changed during these known periods of climate variation and for validating or constraining climate models.The PIs? immediate goal is to reconstruct annual hydrographic variability during key climate intervals within the last millennium along the strategically located Arctic islands of Ingoy and Rolvsoy. They will hindcast changes in annual sea surface temperature (SST) and sea surface salinity (SSS). They will also establish the baseline variability in the marine radiocarbon reservoir effect. The modern near-surface oceanography along the islands is influenced by the physical properties of the Norwegian Coastal Current, while the relatively deep hydrographic conditions predominately depend on Atlantic inflow. Pilot data from the study site demonstrate a strong link between shell-based records and regional SST/SSS conditions. Hence, Ingoy and Rolvsoy seem situated in an ideal location to study marine climate change during the late Holocene. Hypotheses and objectives have been developed to test the relative influence of dominant climate modes on the regional oceanography near northern Norway during the last millennium.Objective 1: Develop near-surface annual shell-based records (master shell chronology and isotopes) to reconstruct regional hydrographic variability (SST and SSS) along the northernmost coast of Norway during intervals of the Medieval Climate Anomaly, the Little Ice Age, and for Modern Climate.Objective 2: Develop relatively deep-water (200 m) annual shell-based records (master shell chronology and isotopes) for the last 100 years to characterize the role of the North Atlantic Current on hydrography at the site.Objective 3: Establish a decadal record of the surface marine radiocarbon reservoir effect since AD 1600 to estimate changes in source water contributions at Ingoy.Objective 4: Estimate the relative influence of the winter North Atlantic Oscillation, the surface Atlantic Meridional Overturning Circulation, and the Atlantic Multidecadal Oscillation on regional hydrography (at Ingoy) and shell-based records.An international partnership for studying Arctic marine climate change will be developed with colleagues from the Akvaplan-niva (Norway), Iowa State University (ISU) and Bates College (Maine). Outreach, public engagement, and dissemination of the results will be accomplished through engagement of two K-12 teachers in the field work, through classroom interactions with K-12 students, through a K-12 teacher workshop, through citizen-based science (via interactions with native Norwegians at Ingoy), and via a photo-journalist who will join the PIs for one field season. At least one female PhD student and approximately five undergraduate students will be supported by and involved with the project. The PIs will use data and ideas developed in this project for several courses at ISU and Bates College relating to climate change, paleoclimate and oceanography. PI Wanamaker will facilitate a public lecture series on climate change at the Ames Public library and continue to act as co-chair of Edwards Elementary Science Night, which has impacted 1,000 students and community members since 2012.