Collaborative Research: Testing Mechanisms of Tropical Climate Change and Variability Using New Cores from the Line Islands

合作研究：利用莱恩群岛的新核心测试热带气候变化和变异的机制

• 批准号: 1405178
• 负责人: Ana Ravelo
• 金额: $ 23.45万
• 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: 2014
• 资助国家: 美国
• 起止时间: 2014-07-15 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1405178&HistoricalAwards=false
• 关键词: Collaborative; Research; Testing; Mechanisms; Tropical; Collaborative; Research; Testing; Mechanisms; Tropical

Coupled ocean-atmosphere interactions in the tropical Pacific are the leading source of modern global interannual climate variability. This variability, expressed as the El Niño-Southern Oscillation (ENSO), extends far beyond the tropical Pacific, affecting climate and human populations globally. Understanding how climate change alters these interactions is therefore critical for human societies to mitigate and adapt to future change. Discovering whether external forcing or internal variability determines ENSO behavior will greatly deepen our theoretical understanding of ENSO and improve our ability to accurately forecast ENSO behavior under altered climates. In addition to these broad scientific and societal benefits, this project will provide research opportunities for graduate and undergraduate students. The project also provides a platform for the development of K-12 teaching modules, which will be designed in collaboration with public school teachers as well as an undergraduate science teacher in training at the University of California, Santa Cruz.This project is developing records of equatorial Pacific Ocean sea-surface temperature variability during the past 250,000 years to test factors that alter tropical climate and the behavior of the El Niño-Southern Oscillation (ENSO). ENSO is the dominant cause of interannual climate variability globally, yet it is not known how its behavior could change with future climate change. Understanding past changes in the behavior of ENSO, when global temperatures were different, will be a significant advance in this regard. ENSO behavior is reconstructed from the variability of sea-surface temperatures determined by the chemistry of fossil foraminifera shells in deep-sea sediments near the Line Islands, in the central Pacific. The Mg/Ca ratio and oxygen isotope composition of each individual planktonic foraminifera shell records a one-month snapshot of sea-surface temperature. Measurement of many individual shells from a single sediment layer documents the variability of sea surface temperatures over the time of deposition. Because ENSO is the primary cause of sea-surface temperature variability near the Line Islands, past changes in temperature variability show how ENSO behavior changed in the past. These data will test the dynamic response of the equatorial Pacific to changes in solar insolation from Earth's orbit, and to glacial-interglacial changes in global temperature and greenhouse gas (pCO2) forcing, improving our understanding of the ENSO phenomenon and how it might change in the future.

热带太平洋中的耦合海洋 - 大气相互作用是现代全球际气候变化的主要来源。这种可变性表示为厄尔尼诺 - 南方振荡（ENSO），远远超出了热带太平洋，影响了全球气候和人类人群。因此，了解气候变化如何改变这些相互作用对于人类社会减轻和适应未来变化至关重要。发现外部强迫或内部变异性是否决定ENSO行为会大大加深我们对ENSO的理论理解，并提高我们在改变气候下准确预测ENSO行为的能力。除了这些广泛的科学和社会利益外，该项目还将为研究生和本科生提供研究机会。该项目还为开发K-12教学模块提供了一个平台，该模块将与公立学校的教师以及加利福尼亚大学圣克鲁斯分校的培训的本科科学老师合作设计。该项目正在开发模棱两可的太平洋海上海景局部温度变化的记录，以改变过去250,000年的测试因素，以改变热带气候和Else-ni ni ni nii nii nii nii nii nii nii nii nii nii nii nii ni i i i ni i i i ni i i i nii ni i i ni i ie的培训。 ENSO是全球气候变化的主要原因，但尚不知道其行为如何随未来的气候变化而变化。当全球温度不同时，了解过去的ENSO行为的变化将是这方面的重大进步。 ENSO行为是根据中太平洋中部太平洋线岛附近的深海沉积物中化石有孔虫壳的化学壳的化学壳确定的海面温度的变异性重建的。每个单独的浮游有孔虫壳的Mg/Ca比和氧同位素组成记录了海面温度一个月的快照。来自单个沉积物层的许多单个壳的测量记录了沉积时间内海面温度的变化。因为ENSO是线岛附近海面温度变化的主要原因，所以过去温度变化的过去变化表明了ENSO行为过去的变化。这些数据将测试赤道太平洋对太阳能隔离的变化的动态响应，以及在全球温度和温室气体（PCO2）强迫的冰川间冰之间变化，增进了我们对ENSO现象的理解以及未来可能如何变化。