Laminated west Greenland lake sediments as unique climatic and biogeochemical archives

层状西格陵兰湖沉积物作为独特的气候和生物地球化学档案

• 批准号: 0520718
• 负责人: Yongsong Huang
• 金额: --
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-15 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0520718&HistoricalAwards=false
• 关键词: Laminated; west; Greenland; lake; sediments

ABSTRACTHuangOPP-0520718Ice cores from the summit of the Greenland ice sheet have provided high-resolution Holocene temperature and precipitation records. However, Greenland is characterized by large spatial variations in climate and its controlling factors. Notably, summit temperature shows little correlation, whereas southwest Greenland coastal temperature shows strong negative correlation with the North Atlantic Oscillation (NAO). The Principal Investigator will construct new high resolution decadal-scale records of temperature and effective precipitation for the past 8000 years from the laminated sediments of three closed basin lakes near the head of the Sondre Stromfjord. The study is an outgrowth of recent research that found unprecedented abundances of long chain alkenones in the sediments of these lakes. The molecular and D/H ratios of alkenones will allow quantitative reconstruction of temperature and effective precipitation, while biomarker abundances and isotope ratios will provide additional assessment of lake biogeochemical changes. Lacustrine alkenone producers have remained elusive to biogeochemists for over 20 years. These study sites offer a unique opportunity to study the identity, diversity and evolution of alkenone producers in lakes using genetic sequencing and laboratory culturing, building upon our initial results indicating excellent preservation of haptophyte DNA in the sediments.Intellectual merits: This study will provide new insights into the Holocene variability ofclimate, NAO and lake biogeochemistry in southern west Greenland. Identification of thelacustrine alkenone producers will allow accurate culture calibration of alkenone unsaturation ratios to environmental variables. Comparative sequence analysis of 18S rDNA preserved in sediments will establish the diversity and evolution of haptophyte algae in the Greenland lakes. Organic geochemical studies have been reported in a number of Antarctic lakes. However, despite the presence of 20,000 lakes in the ice-free margins of Greenland, our ABSTRACTHuangOPP-0520718Ice cores from the summit of the Greenland ice sheet have provided high-resolution Holocene temperature and precipitation records. However, Greenland is characterized by large spatial variations in climate and its controlling factors. Notably, summit temperature shows little correlation, whereas southwest Greenland coastal temperature shows strong negative correlation with the North Atlantic Oscillation (NAO). The Principal Investigator will construct new high resolution decadal-scale records of temperature and effective precipitation for the past 8000 years from the laminated sediments of three closed basin lakes near the head of the Sondre Stromfjord. The study is an outgrowth of recent research that found unprecedented abundances of long chain alkenones in the sediments of these lakes. The molecular and D/H ratios of alkenones will allow quantitative reconstruction of temperature and effective precipitation, while biomarker abundances and isotope ratios will provide additional assessment of lake biogeochemical changes. Lacustrine alkenone producers have remained elusive to biogeochemists for over 20 years. These study sites offer a unique opportunity to study the identity, diversity and evolution of alkenone producers in lakes using genetic sequencing and laboratory culturing, building upon our initial results indicating excellent preservation of haptophyte DNA in the sediments.Intellectual merits: This study will provide new insights into the Holocene variability ofclimate, NAO and lake biogeochemistry in southern west Greenland. Identification of thelacustrine alkenone producers will allow accurate culture calibration of alkenone unsaturation ratios to environmental variables. Comparative sequence analysis of 18S rDNA preserved in sediments will establish the diversity and evolution of haptophyte algae in the Greenland lakes. Organic geochemical studies have been reported in a number of Antarctic lakes.

格陵兰冰盖顶部的冰芯提供了高分辨率的全新世温度和降水记录。然而，格陵兰的特点是气候及其控制因素的空间变化很大。值得注意的是，山顶温度几乎没有相关性，而格陵兰西南沿海温度与北大西洋涛动（NAO）呈强烈的负相关。首席研究员将构建新的高分辨率十年尺度的温度和有效降水记录，在过去的8000年里，从三个封闭的盆地湖泊附近的Sondre Stromfjord的头层沉积物。 这项研究是最近研究的结果，该研究发现这些湖泊的沉积物中含有前所未有的大量长链烯酮。烯酮的分子和D/H比将允许定量重建的温度和有效降水，而生物标志物丰度和同位素比将提供额外的评估湖泊地球化学变化。湖相烯酮生产者仍然难以捉摸的地球化学家超过20年。这些研究地点提供了一个独特的机会，研究的身份，多样性和进化的烯酮生产者在湖泊中使用基因测序和实验室培养，建立在我们的初步结果表明良好的保存附着植物DNA在sodium.Intellectual优点：这项研究将提供新的见解全新世气候，NAO和湖泊地球化学的变化在格陵兰岛西南部。确定湖相烯酮生产者将允许准确的文化校准的烯酮不饱和度比环境变量。沉积物中保存的18 S rDNA的比较序列分析将建立在格陵兰湖的附着藻类的多样性和进化。据报道，在南极的一些湖泊中进行了有机地球化学研究。然而，尽管格陵兰岛无冰边缘存在20，000个湖泊，但我们的 格陵兰冰盖顶部的冰芯提供了高分辨率的全新世温度和降水记录。然而，格陵兰的特点是气候及其控制因素的空间变化很大。值得注意的是，山顶温度几乎没有相关性，而格陵兰西南沿海温度与北大西洋涛动（NAO）呈强烈的负相关。首席研究员将构建新的高分辨率十年尺度的温度和有效降水记录，在过去的8000年里，从三个封闭的盆地湖泊附近的Sondre Stromfjord的头层沉积物。 这项研究是最近研究的结果，该研究发现这些湖泊的沉积物中含有前所未有的大量长链烯酮。烯酮的分子和D/H比将允许定量重建的温度和有效降水，而生物标志物丰度和同位素比将提供额外的评估湖泊地球化学变化。湖相烯酮生产者仍然难以捉摸的地球化学家超过20年。这些研究地点提供了一个独特的机会，研究的身份，多样性和进化的烯酮生产者在湖泊中使用基因测序和实验室培养，建立在我们的初步结果表明良好的保存附着植物DNA在sodium.Intellectual优点：这项研究将提供新的见解全新世气候，NAO和湖泊地球化学的变化在格陵兰岛西南部。确定湖相烯酮生产者将允许准确的文化校准的烯酮不饱和度比环境变量。沉积物中保存的18 S rDNA的比较序列分析将建立在格陵兰湖的附着藻类的多样性和进化。据报道，在南极的一些湖泊中进行了有机地球化学研究。