Multicentury records of ENSO and rainfall in corals from northern Australia

ENSO 和澳大利亚北部珊瑚降雨的多世纪记录

• 批准号: 1559323
• 负责人: Julia Cole
• 金额: $ 44万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-15 至 2018-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1559323&HistoricalAwards=false
• 关键词: Multicentury; records; ENSO; rainfall; corals

This project integrates two fundamental issues of global environmental change, tropical climate variations and coral reef vitality. By developing linked histories of reef climate and coral growth on the remote northern Great Barrier Reef, this research will illustrate how the region's climate has changed over the past 200+ years and how coral growth has varied in response. Corals in this region can survive for centuries, and a core from the top to the bottom of a long-lived coral colony reveals annual banding that documents the rate of coral growth over that time. The coral's skeletal chemistry tracks the environmental conditions (temperature, salinity, sedimentation) under which the coral grew. Because the corals grow at a rate of a centimeter or more each year, cores can be sampled at a scale of weeks to months to determine short-term (seasonal) as well as long-term (century) trends in growth and environment. The project takes advantage of cores already recovered from northern Australia, where temperature and salinity are closely tied to the state of the El Niño system. El Niño influences climate around the world. This research will help climate scientists understand how El Niño is changing as the world warms and whether recent strong El Niño events are unusual or within the range of natural behavior. By linking the climate record to a history of coral growth from the same core, this project will help coral ecologists to see the connections between climate variations and coral growth rates from seasonal to century time scales. The research includes collaboration with the Australian Institute of Marine Sciences (AIMS), which advises the Australian government on reef management and conservation. By spending a summer at AIMS, a graduate student will receive high-level experience in issues of coral health, growth, and conservation that are critical for managing reefs here in the US as well as abroad. Project participants will engage in interdisciplinary climate research at the University of Arizona, including climate model analysis, the global impacts of El Niño, and communicating their work to a broader audience through public presentations at Biosphere-2. The specific goals of this project include the following:- Use multicentury, subseasonal measurements of coral δ18O and Sr/Ca to define the natural variability of temperature and salinity in this region, and their relationship to regional climate; - Extract seasonally specific histories of El Niño and Australian monsoon rainfall to compare with other records and evaluate for long-term variability; - Compare geochemical histories with luminescent and growth band properties to evaluate agreement and sensitivity as proxies for environmental change; - Use the multivariate information from corals to assess relationships among environmental variations (SST, SSS, and sedimentation) and coral growth (extension, calcification); - Incorporate records into broader analyses of tropical variability, e.g. long-term variations and trends, large-scale patterns, multiproxy syntheses, and comparisons to GCM simulations. This project represents a major advance in climate and coral studies. Despite the long history of coral paleoclimatology, this will be the first integration of geochemical and growth-band characteristics at a subseasonal, multicentury scale. Multiple paleoclimate proxies will yield broadly useful reconstructions of El Niño and monsoon rainfall and reveal how environmental changes influence coral growth. These results will be incorporated into large-scale syntheses to improve understanding of long-term tropical variability. All results will be publically shared with reef managers and other stakeholders, as part of the AIMS mission of science-based conservation, and presented in Arizona to the thousands of visitors that pass through the University of Arizona's Biosphere-2.

该项目整合了全球环境变化，热带气候变化和珊瑚礁活力的两个基本问题。通过开发礁石气候和珊瑚北美大礁石礁的珊瑚礁增长历史，这项研究将说明该地区气候在过去200多年中的变化以及珊瑚增长的反应如何变化。该地区的珊瑚可以存活几个世纪，从长寿命的珊瑚殖民地的顶部到底部的核心揭示了年度乐队，记录了那个时候珊瑚增长率。珊瑚的骨骼化学跟踪珊瑚生长的环境条件（温度，盐度，沉积）。由于每年以厘米或更高的速度的珊瑚增长，可以在数周到数月的时间内对核心进行采样，以确定长期（季节性）以及长期（世纪）生长和环境的长期趋势。该项目充分利用已经从澳大利亚北部回收的核心，那里的温度和盐度与厄尔尼诺现状紧密相关。厄尔尼诺影响世界各地的气候。这项研究将帮助气候科学家了解厄尔尼诺现象如何随着世界的温暖以及最近的强大厄尔尼诺事件是不寻常的还是在自然行为范围内的。通过将气候记录与来自同一核心的珊瑚增长史联系起来，该项目将帮助珊瑚生态学家看到气候变化与从季节性到世纪时间尺度的珊瑚增长率之间的联系。该研究包括与澳大利亚海洋科学研究所（AIMS）的合作，该研究所为澳大利亚政府就礁石管理和保护提供了建议。通过在AIMS度过一个夏天，研究生将获得在珊瑚健康，增长和保护问题方面的高级经验，这对于在美国和国外管理礁石至关重要。项目参与者将在亚利桑那大学（University of Arizona）进行跨学科的气候研究，包括气候模型分析，厄尔尼诺现象的全球影响，并通过Biosphere-2的公开演讲将其作品传达给更广泛的受众。该项目的具体目标包括以下内容： - 使用珊瑚的跨越多个月，亚季节测量值和SR/CA来定义该地区温度和盐度的自然变异性，以及它们与区域气候的关系； - 提取厄尔尼诺和澳大利亚季风降雨的季节特定历史，以与其他记录进行比较，并评估长期可变性； - 将地球化学历史与发光和生长带的特性进行比较，以评估一致性和敏感性作为环境变化的代理； - 使用从珊瑚的多元信息到环境变化之间的评估关系（SST，SSS和沉积）和珊瑚生长（扩展，钙化）； - 将记录纳入热带变异性的更广泛分析，例如长期变化和趋势，大规模模式，多Xy合成以及与GCM模拟的比较。该项目代表了气候和珊瑚研究的重大进步。尽管珊瑚古气候学有悠久的历史，但这将是地球化学和生长频段特征在亚季节，多学期规模上的首次整合。多个古气候代理将产生厄尔尼诺和季风降雨的广泛有用的重建，并揭示环境变化如何影响珊瑚的生长。这些结果将纳入大规模合成，以提高对长期热带变异性的理解。作为基于科学的保护的目标的一部分，所有结果将与珊瑚礁经理和其他利益相关者公开共享，并在亚利桑那州向亚利桑那州成千上万的游客介绍，这些游客经过亚利桑那大学的生物圈-2。