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

在这个项目中，研究者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，研究人员将开发中期水营养浓度的古海洋学重建，并提供中期水生物地球化学的第一个连续高分辨率（年际-年代际尺度）记录，这将扩展现代仪器记录。这些记录将促进我们对大气/海洋表面气候、上升流、生产力和深海碳和养分循环的快速变化机制的理解。研究员将通过在一所小型文理学院建立一个新的珊瑚地球化学研究方案，将研究纳入教育活动，并支持代表性不足的群体在本科和高中阶段参与海洋科学。气候变化对诸如上升流、养分有效性、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研究过去气候、碳循环和海洋氧合的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-年代际）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。这项研究围绕着一个核心问题：加州洋流系统的深海营养生物地球化学和碳循环如何受到气候变化的影响？竹珊瑚骨架中保存的微量元素比（Ba/Ca）将用于确定地表-海洋-大气气候变化是否在年代际尺度上影响中间水团养分循环。特别是，本研究将密切研究过去400年的情况，重点关注：(1)验证在加利福尼亚洋流系统（CCS）竹珊瑚（Ba/Ca）中已建立的中间水营养物代理的使用，(2)了解中间水营养物与CCS初级生产力之间的关系，以及(3)CCS出口生产与过去快速气候变化之间的关系（例如太平洋年代际涛动和El Niño南方涛动）。一套独特的珊瑚档案允许在中间水域（792-2055米的总水深）进行深度样带，并与仪器记录直接比较。

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.