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.
