Laminated west Greenland lake sediments as unique climatic and biogeochemical archives

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，格陵兰岛的气候及其控制因素具有较大的空间差异。值得注意的是，峰顶温度与北大西洋涛动（NAO）的相关性不大，而格陵兰西南海岸温度与北大西洋涛动（NAO）的相关性较强。首席研究员将从桑德雷·斯特罗姆峡湾河口附近的三个封闭盆地湖泊的层状沉积物中构建过去8000年的温度和有效降水的新的高分辨率十年尺度记录。这项研究是最近一项研究的结果，该研究发现这些湖泊的沉积物中含有前所未有的长链烯烃。烯酮的分子和D/H比值将用于温度和有效降水的定量重建，而生物标志物丰度和同位素比值将为湖泊生物地球化学变化提供额外的评估。20多年来，湖相烯烃生产商一直是生物地球化学家难以捉摸的问题。这些研究地点提供了一个独特的机会，利用基因测序和实验室培养来研究湖泊中烯酮生产者的身份、多样性和进化，建立在我们初步结果的基础上，表明沉积物中有很好的触觉DNA保存。学术价值：本研究将为格陵兰岛西部南部全新世气候变化、NAO和湖泊生物地球化学提供新的见解。对湖泊烯烃生产者的鉴定将允许对烯烃不饱和比与环境变量的准确培养校准。对沉积物中保存的18S rDNA进行序列比较分析，将有助于确定格陵兰湖中褐藻的多样性及其演化。有机地球化学研究已在一些南极湖泊中得到报道。然而，尽管格陵兰岛无冰边缘存在2万个湖泊，但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，格陵兰岛的气候及其控制因素具有较大的空间差异。值得注意的是，峰顶温度与北大西洋涛动（NAO）的相关性不大，而格陵兰西南海岸温度与北大西洋涛动（NAO）的相关性较强。首席研究员将从桑德雷·斯特罗姆峡湾河口附近的三个封闭盆地湖泊的层状沉积物中构建过去8000年的温度和有效降水的新的高分辨率十年尺度记录。这项研究是最近一项研究的结果，该研究发现这些湖泊的沉积物中含有前所未有的长链烯烃。烯酮的分子和D/H比值将用于温度和有效降水的定量重建，而生物标志物丰度和同位素比值将为湖泊生物地球化学变化提供额外的评估。20多年来，湖相烯烃生产商一直是生物地球化学家难以捉摸的问题。这些研究地点提供了一个独特的机会，利用基因测序和实验室培养来研究湖泊中烯酮生产者的身份、多样性和进化，建立在我们初步结果的基础上，表明沉积物中有很好的触觉DNA保存。学术价值：本研究将为格陵兰岛西部南部全新世气候变化、NAO和湖泊生物地球化学提供新的见解。对湖泊烯烃生产者的鉴定将允许对烯烃不饱和比与环境变量的准确培养校准。对沉积物中保存的18S rDNA进行序列比较分析，将有助于确定格陵兰湖中褐藻的多样性及其演化。有机地球化学研究已在一些南极湖泊中得到报道。

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.