Collaborative Research: High Latitude Temperature and Biological Responses to Plio-Pleistocene Global Change

合作研究：高纬度温度和对上更新世全球变化的生物反应

• 批准号: 0623487
• 负责人: Timothy Herbert
• 金额: $ 29.87万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0623487&HistoricalAwards=false
• 关键词: Collaborative; Research; Latitude; Temperature; Biological

Herbert and Lawrence Proposal Abstract 0623487This project seeks to improve our understanding of how conditions in the high latitude oceans of both hemispheres changed over the course of the Earth's last major climate revolution from 2-4 million years ago (Ma). During this period, the northern hemisphere became glaciated, and large amplitude climate cycles began that continue to the present. The PI's propose to reconstruct time series (average sampling resolution of 3 ka) of past ocean surface temperature and biological activity from a number of deep sea sites in the N and S hemispheres with continuous sediment coverage across the 2-4 Myr time interval. State-of-the-art organic geochemical analyses of alkenone biomolecules will be utilized together with stable isotope measurements on benthic foraminifera to provide accurate dating of the samples. This project will test hypotheses that 1) temperature variability at the high latitudes grew substantially from 4 to 3 Ma and that glaciation was a late response (rather than a primary driver) to earlier shifts in the climate system; 2) the pattern of high latitude ocean cooling was more or less symmetrical in the two hemispheres, suggesting that declining greenhouse gas levels played a major role in the onset of northern hemisphere glaciation and 3) biological productivity shifted at approximately the same time in both hemispheres, indicating a major change in the planetary wind fields at high latitudes, and a major reorganization of the ocean carbon "pump" as northern hemisphere ice ages intensified.Broader impacts of the project will include educational/outreach activities and the dissemination of a large and unique data set to the paleoclimatic/climatology community. This project will support undergraduate participation and will contribute to graduate and post-doctoral training and development. Research data will be posted on the NGDC Paleoclimate web site.

赫伯特和劳伦斯提案摘要0623487这个项目旨在提高我们对两个半球高纬度海洋中的状况如何在地球上一届重大气候革命（MA）（MA）中发生变化的理解。 在此期间，北半球变得冰川，并且开始持续到现在。 PI提议从N和S半球的许多深海地点重建过去海面温度和生物学活性的时间序列（平均抽样分辨率），并在2-4 MYR时间间隔内具有连续的沉积物覆盖率。 将使用烯酮生物分子的最先进的有机地球化学分析，并将其与底栖有孔虫上稳定的同位素测量一起使用，以提供样品的准确测定。 该项目将检验假设，即1）高纬度的温度可变性从4 ma增长到3 Ma，而冰川速度是较晚的响应（而不是主要驱动力），以对气候系统的早期变化； 2）在两个半球中，高纬度海冷却的模式或多或少是对称的，这表明温室气水平下降在北半球冰川的一开始中起着重要作用，而3）生物生产力在两个半球的生物生产力大约相同的时间变化，表明北方风田的主要变化是高公路和一名大型corrand''的主要变化。半球冰年龄加剧了。该项目的影响力将包括教育/外展活动以及向古气候/气候学界传播大型而独特的数据。 该项目将支持本科参与，并将为研究生和博士后培训和发展做出贡献。 研究数据将发布在NGDC古气候网站上。