CAREER: Contextualizing recent extreme El Nino events over the late Holocene using trace element paleothermometry in tropical Pacific corals

该项目将在热带太平洋产生基于珊瑚的海面温度重建。这些记录将记录过去3000年的厄尔Niño-Southern涛动（ENSO）气候现象。如今，ENSO每隔几年就会推动全球天气模式的变化。它起源于热带太平洋和大气，可产生严重而深远的影响，影响自然环境和数十亿人的生活。过去几十年发生的一系列极端厄尔尼诺Niño事件表明，大气温室气体的增加可能导致ENSO事件加剧。然而，ENSO在变暖的世界中如何变化尚不清楚。在理解ENSO方面的进展目前受到仪器海面温度记录持续时间短的限制。使用古气候代理数据的方法提供了一种估算仪器时代之前温度的方法。然而，那些较长的代理温度记录依赖于基于珊瑚的稀疏记录网络。该项目将通过从太平洋中部和东部产生约40个新的长达数十年的珊瑚温度记录来减少数据差距。该项目的教育和推广活动包括努力从地球科学领域代表性不足的群体中招收和留住本科生，并加强佛罗里达州立大学本科课程的主动学习。它们还包括发展跨学科的研究生研究机会，努力提高北佛罗里达高中的科学素养。该项目包括四年的研究生支持和每年对本科生研究人员的支持。该项目将产生40个新的定量温度记录，这些记录来自赤道太平洋的关键地区，横跨暖池的东部边缘到冷舌的核心。整体重建方法将使用比过去传统上使用的更小、更广泛的珊瑚档案——珊瑚碎石——并且测量将结合传统的Sr/Ca测量与较新的Sr- u技术。将采用严格的成岩作用筛选工具，包括微观分析，从化石记录中提取可靠的气候信息。重建将为赤道太平洋海面温度在季节到千年时间尺度上的演变提供前所未有的定量约束，包括描述自工业时代以来极端ENSO事件的统计数据是否以及如何变化，相对于之前的3000年地球历史。该项目的教育目标将增加研究的范围和影响，同时也解决地球科学教育的突出需求。这些教育目标的重点是扩大专业发展机会，技能建设，以及研究生和博士后进入科研队伍的多样性和领导力培训。该项目还将把研究与国际实地的社区需求和教育结合起来。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will produce coral-based sea surface temperature reconstructions in the tropical Pacific Ocean. These records will document the El Niño-Southern Oscillation (ENSO) climate phenomenon during the last 3000 years. Today, ENSO drives changes in weather patterns around the globe every few years. It originates in the tropical Pacific Ocean and atmosphere and can have severe and far-reaching impacts that affect the natural environment and the lives of billions of people. A series of extreme El Niño events over the last several decades suggests that rising atmospheric greenhouse gases may be causing ENSO events to intensify. However, how ENSO may change in a warmer world is not well known. Advances in understanding ENSO are currently limited by the short duration of instrumental sea surface temperature records. Approaches that use paleoclimate proxy data provide a way to produce temperature estimates from before the instrumental era. However, those longer proxy temperature records rely on sparse networks of coral-based records. This project will reduce that data gap by producing ~40 new decades-long coral-based temperature records from the central and eastern Pacific Ocean. The project’s education and outreach activities include efforts to recruit and retain undergraduates from groups underrepresented in the earth sciences and to strengthen active learning in the Florida State University undergraduate curriculum. They also include development of cross-disciplinary graduate research opportunities and efforts to improve science literacy in northern Florida high schools. The project includes four years of graduate student support and support for undergraduate researchers each year.The project will generate 40 new quantitative temperature records over the last 3,000 years from key regions of the equatorial Pacific Ocean spanning the eastern edge of the warm pool to the core of the cold tongue. An ensemble reconstruction approach will use smaller, more widely available coral archives than have traditionally been used in the past – coral rubble – and measurements will combine traditional Sr/Ca measurements with newer Sr-U techniques. Rigorous screening tools for diagenesis, including microscale analyses, will be employed to extract reliable climate information from the fossil records. The reconstructions will provide unprecedented quantitative constraints on the evolution of equatorial Pacific sea surface temperatures on seasonal to millennial time scales, including characterizing whether and how the statistics of extreme ENSO events have changed since the industrial era, relative to the prior 3,000 years of Earth history. The educational objectives of the project will increase the scope and impact of the research, while also addressing outstanding needs in geoscience education. These educational objectives focus on expanding professional development opportunities, skill building, and diversity and leadership training for graduate students and postdocs entering the scientific workforce. The project will also integrate research with community needs and education at international field sites.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.