Assessing tropical Pacific climate variability since the Early Pliocene warm period

评估上新世早期温暖期以来的热带太平洋气候变化

• 批准号: 1204254
• 负责人: Ana Ravelo
• 金额: $ 33.59万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2016-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1204254&HistoricalAwards=false
• 关键词: Assessing; tropical; Pacific; climate; variability

Paleoceanographic studies have shown that early Pliocene warm period (~3.0 to 4.5 million years ago) was characterized by a permanent El Niño-like mean state. However, it is unclear how high frequency climate variability (e.g., the El Niño Southern Oscillation, or ENSO) was different (if at all), and more generally, how ENSO was impacted by changes in the mean state of the climate system. Questions remain about potential biases in the data, and little is known about high frequency tropical Pacific climate variability during the early Pliocene warm period.This accomplishment-based renewal aims to address these outstanding issues by building on over fifteen years of prior research by the lead investigator, a professor at the University of California at Santa Cruz. Her pioneering work has established much of what is known about the Pliocene, the most recent period in Earth's history when when the average global temperature was higher than today for a sustained period of time. This two part study will include 1) synthesis and review of existing records of early Pliocene variability on different time scales, and 2) generation of new paired Mg/Ca-d18O analyses on single foraminifer shells in order to evaluate within-sample variability thought to be related to high frequency ENSO variability. The principal investigator has trained a generation of students in the techniques and questions framing this research. A graduate student will also be involved in this research and synthesis. A significant part of the proposed work will be a workshop on tropical Pacific climate variability during times of global warmth, especially significant because the Pliocene warm period is thought to be a potential analog for future climate.

古海洋学研究表明，上新世早期温暖期（约300万至450万年前）的特征是永久性的厄尔尼诺平均状态。然而，目前还不清楚高频率的气候变率（例如，厄尔尼诺/南方涛动（ENSO）是不同的（如果有的话），更一般地说，ENSO如何受到气候系统平均状态变化的影响。关于数据中潜在偏差的问题仍然存在，对上新世早期温暖时期热带太平洋气候变化的高频知之甚少，这一基于证据的更新旨在通过建立在首席研究员，加州大学圣克鲁斯教授超过15年的研究基础上来解决这些悬而未决的问题。她的开创性工作已经建立了关于上新世的大部分已知信息，上新世是地球历史上最近的一个时期，当时全球平均气温持续高于今天。 这两个部分的研究将包括1）合成和审查现有记录的上新世早期的变化在不同的时间尺度上，和2）生成新的成对的Mg/Ca-d18 O分析单有孔虫壳，以评估样本内的变化被认为是与高频ENSO变化。首席研究员已经培训了一代学生的技术和问题框架这项研究。一名研究生也将参与这项研究和综合。拟议工作的一个重要部分将是举办一个关于全球变暖期间热带太平洋气候变异性的讲习班，这一点特别重要，因为上新世温暖期被认为是未来气候的一个潜在模拟。