EC-10. Investigating Wintertime Sources of Organic Aerosols in Cape Cod, Massachusetts

Abstract
Aerosol sources and chemical processes exhibit seasonal differences as a result of variations in emissions and photochemistry. However, field studies have largely focused on understanding summertime conditions leaving winter understudied. Here, we analyze Aerosol Mass Spectrometer (AMS) measurements of aerosol chemical composition obtained during the Two-Column Aerosol Project (TCAP) that took place from February 4, 2013 to March 6, 2013 in Cape Cod, Massachusetts. To identify the aerosol sources, Positive Matrix Factorization (PMF), source apportionment, meteorological data, and NOAA HYSPLIT back trajectories were used. Organic aerosol (OA) is a major component of aerosol observed in winter months; more specifically, we identify different aerosol sources including primary organic aerosol (POA) directly emitted into the atmosphere (for example, from biomass burning, likely residential wood combustion) and secondary organic aerosol (SOA). In the Cape Cod region, we see aerosols from continental outflow were also transported over marine regions allowing for insight into aerosol aging. Analysis from this study improves our understanding of aerosol sources and processing in a polluted urban outflow region.