Sources and Evolution of Wintertime Organic Aerosol in the Northeastern US. JASON SCHRODER, Pedro Campuzano-Jost, Douglas Day, Nicola Blake, Alan Hills, Rebecca Hornbrook, Eric Apel, Andrew Weinheimer, Teresa Campos, Viral Shah, Kelsey Larson, Jaegle Lyatt, Jose-Luis Jimenez, CIRES, University of Colorado, Boulder