NO3/N2O5 Fate during the 2013 Southern Oxidant and Aerosol Study
Benjamin R Ayres1, Danielle Draper1, Hannah Allen1, Robert J Wild2, Steven S Brown3, Doug A Day4, Pedro Campuzano-Jost5, Brett B Palm6, Weiwei Hu7, Jose L Jimenez8, Ben H Lee9, Claudia Mohr10, Joel A Thornton11, Kaitlin Duffey12, Paul Romer Present12, Ronald C Cohen13, Abigail Koss14, Joost A de Gouw15, Kevin Frederick Olson12, Allen H Goldstein16 and Juliane Fry17, (1)Reed College, Portland, OR, United States, (2)Colorado University/NOAA/ESRL, Boulder, CO, United States, (3)NOAA, Earth System Research Laboratory, Boulder, CO, United States, (4)Cooperative Institute for Research in Environmental Sciences (CIRES), Boulder, United States, (5)University of Colorado Boulder, Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, Boulder, United States, (6)University of Colorado at Boulder, Boulder, United States, (7)Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China, (8)Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado Boulder, Boulder, United States, (9)Univ Washington - Seattle, Seattle, WA, United States, (10)University of Washington Seattle Campus, Seattle, WA, United States, (11)University of Washington, Department of Atmospheric and Climate Science, Seattle, United States, (12)University of California Berkeley, Berkeley, CA, United States, (13)University of California, Berkeley, Department of Chemistry, Berkeley, United States, (14)University of Colorado at Boulder, Boulder, CO, United States, (15)University of Colorado Boulder, Department of Chemistry, Boulder, United States, (16)University of California Berkeley, Department of Civil & Environmental Engineering, Berkeley, CA, United States, (17)Reed College, Chemistry and Environmental Studies, Portland, OR, United States
Abstract:
Nitrate radical (NO3) was found to be a significant oxidant of biogenic volatile organic compounds (BVOCs) at the Southern Oxidant and Aerosol Study (SOAS), conducted in Summer 2013. NO3 + BVOC reactions were responsible for a substantial (50%) fraction of losses even during daylight hours when photolysis and NO reactions are rapid NO3 sinks. Steady-state calculated NO3 and measured BVOC concentrations were used to predict accumulated NO3 loss and these values were correlated with total gas- and aerosol-phase alkyl nitrate measurements taken with TD-LIF and aerosol organic nitrate mass measured by Aerosol Mass Spectrometry (AMS). This enabled determination of the BVOCs most responsible for NO3 loss during periods of aerosol growth. Further correlations with specific organonitrates measured by Chemical Ionization Mass Spectrometry (CIMS) allow assignment of several individual product molecules connected to secondary organic aerosol formation in the southeastern United States.
