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

合作研究：从挪威沿海新开发的年度贝壳记录中探索海洋和大气强迫对北极海洋气候的作用

• 批准号: 1417636
• 负责人: Michael Retelle
• 金额: $ 33.72万
• 依托单位: Bates College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1417636&HistoricalAwards=false
• 关键词: Collaborative; research; Exploring; role; oceanic

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.

海洋学家和古气候学家使用各种代用物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，但沉积速率很小，因此可以从它们估计的时间序列只能解决发生在十年或更长时间尺度上的变化。当蛤蜊和其他双壳类动物生长时，它们在壳中加入了它们所生活的水的地球化学特征。它们还会在壳里埋下年轮，就像树的年轮一样。通过研究长寿命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温度和盐度变化。他们将集中精力研究中世纪温暖期（公元1000年至1200年）、小冰期（公元1200年至1850年）和现代（公元1850年至今）。由此得出的温度和盐度变化的历史将有助于理解在这些已知的气候变化时期海洋条件是如何变化的，并有助于验证或限制气候模式。π吗?当前的目标是重建过去一千年中沿战略位置的北极岛屿印哥伊岛和罗尔夫索伊岛关键气候间隔的年度水文变化。它们将对年海面温度（SST）和海面盐度（SSS）的变化进行后验。他们还将建立海洋放射性碳储层效应的基线变异性。现代岛屿近地表海洋学受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。研究现场的试点数据表明，基于壳的记录与区域海温/SSS条件之间存在很强的联系。因此，Ingoy和Rolvsoy似乎处于研究全新世晚期海洋气候变化的理想位置。在过去的一千年中，为了测试挪威北部附近的主要气候模式对区域海洋学的相对影响，已经制定了假设和目标。目标1：开发基于贝壳的近地表年度记录（主贝壳年代学和同位素），以重建挪威最北海岸在中世纪气候异常、小冰期和现代气候期间的区域水文变化（SST和SSS）。目标2：开发过去100年相对深水（200米）年度贝壳记录（主贝壳年代学和同位素），以表征北大西洋洋流对该地点水文学的作用。目标3：建立自公元1600年以来的海洋表层放射性碳储层效应的年代际记录，以估计源水贡献的变化。目标4：估计冬季北大西洋涛动、大西洋表层经向翻转环流和大西洋多年代际涛动对区域水文（在Ingoy）和基于壳的记录的相对影响。研究北极海洋气候变化的国际伙伴关系将与来自挪威的Akvaplan-niva、爱荷华州立大学（ISU）和缅因州贝茨学院（Bates College）的同事建立。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，通过以公民为基础的科学（通过与英格伊当地挪威人的互动），以及通过一名摄影记者加入pi的一个实地季节，将完成外延、公众参与和结果的传播。至少有一名女博士生和大约五名本科生将得到支持并参与该项目。项目负责人将在ISU和贝茨学院的几门有关气候变化、古气候和海洋学的课程中使用在这个项目中形成的数据和想法。皮·沃纳梅克将在艾姆斯公共图书馆举办一系列关于气候变化的公开讲座，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年以来影响了1000名学生和社区成员。