Ayres, B. R.Allen, H. M.Draper, D. C.Brown, S. S.Wild, R. J.Jimenez, J. L.Day, D. A.Campuzano-Jost, P.Hu, W.De Gouw, J.Koss, A.Cohen, R. C.Duffey, K. C.Romer, P.Baumann, K.Edgerton, E.Takahama, S.Thornton, J. A.Lee, B. H.Lopez-Hilfiker, F. D.Mohr, C.Wennberg, P. O.Nguyen, T. B.Teng, A.Goldstein, A. H.Olson, K.Fry, J. L.2016-02-162016-02-162016-02-16201510.5194/acp-15-13377-2015https://infoscience.epfl.ch/handle/20.500.14299/123598WOS:000367189600007Gas- and aerosol-phase measurements of oxidants, biogenic volatile organic compounds (BVOCs) and organic nitrates made during the Southern Oxidant and Aerosol Study (SOAS campaign, Summer 2013) in central Alabama show that a nitrate radical (NO3) reaction with monoterpenes leads to significant secondary aerosol formation. Cumulative losses of NO3 to terpenes are correlated with increase in gas- and aerosol- organic nitrate concentrations made during the campaign. Correlation of NO3 radical consumption to organic nitrate aerosol formation as measured by aerosol mass spectrometry and thermal dissociation laser-induced fluorescence suggests a molar yield of aerosol-phase monoterpene nitrates of 23-44 %. Compounds observed via chemical ionization mass spectrometry (CIMS) are correlated to predicted nitrate loss to BVOCs and show C10H17NO5, likely a hydroperoxy nitrate, is a major nitrate-oxidized terpene product being incorporated into aerosols. The comparable isoprene product C5H9NO5 was observed to contribute less than 1% of the total organic nitrate in the aerosol phase and correlations show that it is principally a gas-phase product from nitrate oxidation of isoprene. Organic nitrates comprise between 30 and 45% of the NOy budget during SOAS. Inorganic nitrates were also monitored and showed that during incidents of increased coarse-mode mineral dust, HNO3 uptake produced nitrate aerosol mass loading at a rate comparable to that of organic nitrate produced via NO3 + BVOCs.text::journal::journal article::research article