RUI: OCE-RIG: Decadal climate, carbon and nutrient variability: New insights from deep-sea bamboo coral records on the California margin

RUI：OCE-RIG：十年间气候、碳和养分变化：来自加州边缘深海竹珊瑚记录的新见解

• 批准号: 1420984
• 负责人: Michele LaVigne
• 金额: $ 10万
• 依托单位: Bowdoin 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: 2014-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1420984&HistoricalAwards=false
• 关键词: RUI; OCE; RIG; Decadal; climate

In this project, the investigator will examine paleoceanographic records to study how ocean productivity, nutrient cycling, and carbon cycling have been impacted by rapid climate variability. To achieve this aim, the investigator will develop paleoceanographic reconstructions of intermediate water nutrient concentration and provide the first continuous high-resolution (interannual-decadal scale) records of intermediate water biogeochemistry that will extend modern instrumental records. These records will advance our understanding of mechanisms linking rapid variations in atmospheric/surface ocean climate, upwelling, productivity, and deep-sea carbon and nutrient cycling. The investigator will integrate the research into educational activities by establishing a new coral geochemistry research program at a small liberal arts college and support participation of under-represented groups in ocean sciences at both the undergraduate and high-school level.The impact of climate change on processes such as upwelling, nutrient availability, carbon export and ocean biogeochemistry is currently poorly understood. Paleoceanographic records can provide critical perspective on the mechanisms linking climate, the carbon cycle, and ocean oxygenation in the past. The investigator will use high-resolution (interannual-decadal) geochemical records from deep-sea bamboo corals to reconstruct past changes in nutrient cycling and carbon export for the past 400 years. The study is focused around a central question: How are deep-sea nutrient biogeochemistry and carbon cycling in the California Current System affected by climate change? Trace elemental ratios preserved in bamboo coral skeleton (Ba/Ca) will be used to determine whether changes in surface-ocean-atmospheric climate affect intermediate water mass nutrient cycling on decadal timescales. In particular, this study will closely investigate the last 400 years with a focus on: (1) validating the use of an established intermediate water nutrient proxy in California Current System (CCS) bamboo corals (Ba/Ca), (2) understanding the relationship between intermediate water nutrients and primary productivity in the CCS, and (3) the relationship between CCS export production and rapid climate change in the past (e.g. the Pacific Decadal Oscillation and the El Niño Southern Oscillation). A unique suite of coral archives allows for a depth transect across intermediate waters (792-2055m water depth, in total) and direct comparison with instrumental records.

在这个项目中，研究人员将检查古海洋学记录，研究海洋生产力，营养循环和碳循环如何受到快速气候变化的影响。为了实现这一目标，研究人员将开发中层水营养盐浓度的古海洋学重建，并提供第一个连续的高分辨率（年际-十年尺度）中层水地球化学记录，将扩展现代仪器记录。这些记录将促进我们对大气/表层海洋气候、上升流、生产力以及深海碳和营养物循环快速变化之间联系机制的理解。研究人员将通过在一所小型文科学院建立一个新的珊瑚地球化学研究项目，将研究纳入教育活动，并支持在本科和高中阶段参与海洋科学的代表性不足的群体，气候变化对上升流，营养物质供应，碳输出和海洋生物地球化学等过程的影响目前知之甚少。古海洋学记录可以为过去气候、碳循环和海洋氧化作用之间的联系机制提供重要的视角。研究人员将使用深海竹珊瑚的高分辨率（年际-十年）地球化学记录来重建过去400年来营养循环和碳输出的变化。这项研究的重点是围绕一个中心问题：气候变化如何影响加州洋流系统中的深海营养盐地球化学和碳循环？竹珊瑚骨架中保存的微量元素比值（Ba/Ca）将用于确定地表-海洋-大气气候的变化是否会影响十年时间尺度上的中层水团营养循环。特别是，这项研究将密切调查过去400年，重点是：（1）验证加州海流系统（CCS）竹珊瑚（Ba/Ca）中已建立的中层水营养物代用品的使用，（2）理解CCS中中层水营养物与初级生产力之间的关系，以及（3）过去CCS出口产量与快速气候变化（例如太平洋十年涛动和厄尔尼诺南方涛动）之间的关系。一套独特的珊瑚档案允许在中间沃茨（水深792- 2055米）进行深度横断面调查，并与仪器记录进行直接比较。