Lake Sediments as Records of Atmospheric Elemental Carbon, ~1900 to 2014

该项目的主要目标是确定上个世纪美国东北部一个地点的大气元素碳（EC）浓度的详细历史，并将其与模型预测进行比较。欧空体气溶胶由于吸收太阳辐射和可能形成云，在区域和全球气候强迫中起关键作用。EC还作为细颗粒物的主要成分影响环境和人类健康。在美国东北部，EC气溶胶的来源在上个世纪发生了巨大变化，这些变化反映在大气中EC的浓度上。然而，过去关于大气EC的数据很少。我们假设大气EC可以通过湖泊沉积物中EC的浓度来确定。2011年至2014年期间，将在纽约白面山收集每日气溶胶样本。这些过滤器以及2006-2010年存档的过滤器将分析EC浓度，以提供1978年至2014年的连续数据。白面山周围三个湖泊沉积物岩心中的EC浓度也将采用冷冻岩心技术测定。我们还将努力定位一个叠层湖，在那里可以使用直接阀（层）计数来获得高度精确的年表和精细的时间分辨率，大约5-10年。这些数据将使湖泊沉积物和大气浓度之间的定量关系得以确定。深层沉积物中的EC浓度将用于估计工业化前的时代背景。存档的湖芯也可以用于研究有毒金属，如汞，和许多其他化学物质，如多环芳烃（PAHs）。本项目将为本科生和博士后研究人员提供教育机会。这项工作的结果将纳入环境化学课程以及跨学科研究。还计划开展公共宣传活动。

The primary objective of this project is to determine a detailed history of atmospheric elemental carbon (EC) concentrations for a site in the Northeastern US over the last century and compare it to model predictions. EC aerosols play a key role in regional and global climate forcing because of absorption of solar radiation and possible cloud formation. EC also impacts the environment and human health as a major component of fine particulate matter. In the northeastern United States, sources of EC aerosols have changed dramatically during the last century, and these changes are reflected in atmospheric concentrations of EC. However, past data on atmospheric EC is sparse. It is hypothesized that atmospheric EC can be determined from the EC concentrations in lake sediments. Daily aerosol samples will be collected at Whiteface Mt., NY between 2011 and 2014. These filters along with archived filters for 2006-2010 will be analyzed for EC concentration to provide continuous data from 1978 to 2014. The EC concentration in sediment cores from three lakes around Whiteface Mt. will also be determined using freeze-coring techniques. Efforts will also be made to locate a laminated lake where direct varve (layer) counting can be used to obtain a highly accurate chronology and fine time resolution, about 5-10 yrs. These data will allow the quantitative relationship between concentrations in lake sediments and the atmosphere to be determined. EC concentrations in deeper sediments are to be used to estimate the pre-industrial age background. The archived lake cores can also be used for studies of toxic metals such as mercury, and many other chemical species, such as polycyclic aromatic hydrocarbons (PAHs). This project will provide educational opportunities for undergraduate students and post-doctoral researchers. The results of this work will incorporated in courses in environmental chemistry as well as interdisciplinary research. Public outreach activities are also planned.