Collaborative Research: Interhemispheric linkages of Late Pleistocene climate change in the circum-Pacific region

合作研究：环太平洋地区晚更新世气候变化的半球间联系

• 批准号: 1024657
• 负责人: Tammy Rittenour
• 金额: $ 16.06万
• 依托单位: Utah State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2014-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1024657&HistoricalAwards=false
• 关键词: Collaborative; Research; Interhemispheric; linkages; Late

This project will investigate past climates in the circum-Pacific region. Specifically, the project will evaluate hypothesized linkages between Southern Hemisphere and Northern Hemisphere climatic processes during the last glaciation, 100,000 to 10,000 years ago. Scientists have long recognized that Northern Hemisphere cooling and warming influence Southern Hemisphere climate, particularly in determining the broad patterns of glacial-interglacial cycles. Conversely, Southern Hemisphere climatic processes have only rarely been invoked as influences on Northern Hemisphere climate. Initial evidence shows apparent correlations in the timing of mountain glacier fluctuations in New Zealand, southern South America, the northwestern United States, and possibly other regions of the circum-Pacific. Those fluctuations occur during minima in Southern Hemisphere solar energy cycles, suggesting that Southern Hemisphere cooling is transmitted through both hemispheres in the Pacific region. This project will investigate glacial sediments and fossil insects in New Zealand and the northwestern US to test that hypothesis. The processes of mountain glaciation in both areas will be determined through detailed evaluation of glacial sediment sequences. The timing of the glacier fluctuations will be determined through optically-stimulated luminescence(OSL) dating of sand grains in the sediments, as well as crystal damage from ambient geological radiation, and on radiocarbon dating of organic sediments. Because glaciers fluctuate in response to both temperature and precipitation changes, the project will utilize fossil chironomids (non-biting midges)preserved in adjacent lake and pond sediments to determine water and air temperatures at specific times during the last glaciation.A thorough evaluation of the timing of climatic changes around the Pacific Ocean margin will provide important insight into how the Earth's climate system functions. Climatic linkages are important to the modern climatic system,as shown by the global influence of El Nino and related processes. This project will therefore also help improve knowledge of how modern climate fluctuates. The project will enhance professional development of students and early career scientists, foster international collaboration, and strengthen educational offerings at three institutions. The project will provide ample opportunities for student research at both undergraduate and graduate levels.

这个项目将调查环太平洋地区过去的气候。具体地说，该项目将评估10万至1万年前最后一次冰川期间南半球和北半球气候过程之间的假设联系。科学家们早就认识到，北半球的降温和变暖影响着南半球的气候，特别是在确定冰川-间冰期循环的广泛模式方面。相反，南半球气候过程很少被引用为对北半球气候的影响。初步证据表明，新西兰、南美南部、美国西北部，可能还有环太平洋其他地区的山脉冰川波动的时间有明显的相关性。这些波动发生在南半球太阳能循环的极小期，这表明南半球的冷却是通过太平洋地区的两个半球传播的。该项目将调查新西兰和美国西北部的冰川沉积物和昆虫化石，以验证这一假设。将通过对冰川沉积序列的详细评估来确定这两个地区的山脉冰川作用过程。冰川波动的时间将通过沉积物中沙粒的光学激发发光(OSL)测年、环境地质辐射对晶体的破坏以及有机沉积物的放射性碳测年来确定。由于冰川会随着温度和降水的变化而波动，该项目将利用保存在邻近湖泊和池塘沉积物中的摇蚊化石来确定上一次冰川期间特定时间的水和气温。对太平洋边缘周围气候变化的时间进行彻底评估将为了解地球气候系统的功能提供重要的洞察。厄尔尼诺现象及其相关过程的全球影响表明，气候联系对现代气候系统很重要。因此，该项目还将有助于提高对现代气候波动的了解。该项目将加强学生和早期职业科学家的专业发展，促进国际合作，并加强三个机构的教育。该项目将为本科生和研究生提供充足的研究机会。