High-resolution, quantitative records of temperature and effective precipitation for the past 25kyr from Lake Qinghai

青海湖近25公里温度和有效降水的高分辨率定量记录

• 批准号: 0902805
• 负责人: Yongsong Huang
• 金额: $ 35.27万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0902805&HistoricalAwards=false
• 关键词: resolution; quantitative; records; temperature; effective

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The Qinghai-Tibetan Plateau occupies the highest elevation on the continental Earth and is renowned for its extraordinary monsoonal climate. It is among the most sensitive regions to global climate change. High resolution, quantitative and long term paleoclimate records from this region are extremely valuable to our understanding of the mechanisms controlling monsoon variability, both regionally and globally. Existing records in the region are hampered by their short duration (e.g., tree rings), multiple influencing factors (e.g., high-altitude ice cores, pollen, lake carbonate del-18O), and qualitative nature (e.g., sediment lithofacies). This grant will reconstruct decadal to centennial scale records of temperature and effective precipitation for the past 25,000 years from the recently recovered sediment cores of Lake Qinghai by the International Continental Drilling Program. Lake Qinghai sediments are rare in that they contain alkenone biomarkers, providing an opportunity for quantitative continental paleoclimate research. This study uses alkenone distributions and compound-specific H isotope ratios of terrestrial and aquatic biomarkers in Lake Qinghai sediments to independently reconstruct temperature, salinity and hydrological balance. It also isolates individual lignin phenols in lake sediments for radiocarbon dating to obtain a robust chronology. The group hypothesize that the amplitude, timing, abruptness and periodicity of temperature and precipitation changes around Lake Qinghai for the past 25,000 yrs display exceptional sensitivity to key climate forcing factors such as insolation, solar activities and greenhouse gases, and show clear linkages to North Atlantic and tropical processes. Close collaboration with modelers will permit transformative synthesis of this comprehensive paleoclimate data set with modeling outcomes to unravel the underlying driving mechanisms of climatic variations.The PI was designated to be in charge of organic geochemical studies for Lake Qinghai by an international group of reserchers. His work represents the United States' participation in the Qinghai drilling project, which obtained high quality paleoclimate records from a strategically important continental region. This study promotes multidisciplinary approaches (organic geochemistry, isotope geochemistry and paleoclimatology) to studying prominent climatic problems, and allows cross-discipline training of students. The PI has demonstrated his commitment to provide cutting edge research experience to undergraduate students by supervising on several under-graduate senior theses per year. This project facilitates participation of graduate students in teaching science in Providence public schools and involvement of Providence school teachers in research through the ongoing NSF GK-12 Education Program at Brown University.

该奖项是根据2009年的《美国复苏与再投资法》（公法111-5）资助的。青海居民高原在大陆地球上占据最高海拔，并以其非凡的季风气候而闻名。它是全球气候变化最敏感的地区之一。来自该地区的高分辨率，定量和长期的古气候记录对于我们对控制季风变异性的机制的理解非常有价值。该地区的现有记录因其短持续时间（例如树环），多个影响因素（例如，高海拔冰核，花粉，碳酸盐DEL-18O）和定性性质（例如，泥沙岩相）受到阻碍。这笔赠款将重建decondal decadal，以从国际大陆钻探计划通过最近回收的青海湖沉积物核心的过去25，000年的温度和有效降水记录重建。青海湖沉积物很少见，因为它们含有烯酮生物标志物，为定量大陆古气候研究提供了机会。这项研究使用烯酮分布以及Qinghai湖沉积物中陆生和水生生物标志物的化合物特异性H同位素比与独立重建温度，盐度和水文平衡。它还可以分离出湖泊沉积物中的单个木质素苯酚，以获得良好的年表。该小组假设，过去25,000年，温度和降水的幅度，时机，明确，突然和周期性和降水的周期性在过去25,000年中表现出对关键气候强迫因素的极为敏感性，例如日光浴，太阳能活动和温室气体，并表现出与北大西洋和热带过程的清晰联系。与建模者的密切合作将允许对这个全面的古气候数据集进行变革性综合，并通过建模结果来揭示气候变化的潜在驾驶机制。该PI被指定为由一组Reserchers组成的Qinghai湖有机地球化学研究。他的工作代表了美国参与青海钻探项目，该项目从战略上重要的大陆地区获得了高质量的古气候记录。这项研究促进了多学科方法（有机地球化学，同位素地球化学和古气候学）来研究突出的气候问题，并允许对学生进行跨学科培训。 PI表明，他致力于通过对本科生每年的几个毕业生高级论文进行监督，为本科生提供尖端的研究经验。该项目促进了研究生在普罗维登斯公立学校的教学科学教学，并通过布朗大学的NSF GK-12教育计划参与Providence School教师研究。