Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 9 1 2009 10.5194/acpd-9-225-2009 http://www.atmos-chem-phys-discuss.net/9/225/2009/ http://www.atmos-chem-phys-discuss.net/9/225/2009/acpd-9-225-2009.html http://www.atmos-chem-phys-discuss.net/9/225/2009/acpd-9-225-2009.pdf 225 269 2009-01-06 Nocturnal isoprene oxidation over the Northeast United States in summer and its impact on reactive nitrogen partitioning and secondary organic aerosol S. S. Brown steven.s.brown@noaa.gov J. A. deGouw C. Warneke T. B. Ryerson W. P. Dubé E. Atlas R. J. Weber R. E. Peltier J. A. Neuman J. M. Roberts A. Swanson F. Flocke S. A. McKeen J. Brioude R. Sommariva M. Trainer F. C. Fehsenfeld A. R. Ravishankara NOAA Earth System Research Laboratory, 325 Broadway, Boulder, CO 80 305, USA Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80 309, USA RSMAS/MAC, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33 149, USA School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA National Center for Atmospheric Research, 1850 Table Mesa Dr., Boulder, CO 80305, USA now at: Department of Environmental Medicine, NYU School of Medicine, Tuxedo, NY 10987, USA now at: Chemical Technology Department, Northrup Grumman Space Technology, Redondo Beach, CA 90278, USA now at: School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK Isoprene is the largest single VOC emission to the atmosphere. Although it is primarily oxidized photochemically during daylight hours, late-day emissions that remain in the atmosphere at sunset undergo oxidation by NO₃ in regionally polluted areas with large NO_x levels. A recent aircraft study examined isoprene and its nocturnal oxidants in a series of night flights across the Northeast US, a region with large emissions of both isoprene and NO_x. Substantial amounts of isoprene that were observed after dark were strongly anticorrelated with measured NO₃ and were the most important factor determining the lifetime of this radical. The products of photochemical oxidation of isoprene, methyl vinyl ketone and methacrolein, were more uniformly distributed, and served as tracers for the presence of isoprene at sunset, prior to its oxidation by NO₃. Comparison of a determination of the mass of isoprene oxidized in darkness by NO₃ to a calculation of integrated isoprene emissions showed that large amounts (>20%) of emitted isoprene may undergo nocturnal oxidation in this region. Organic nitrates produced from the NO₃+isoprene reaction, though not directly measured, were estimated to account for 2–9% of total reactive nitrogen and 7–31% of other long-lived organic nitrates such as PAN. The mass of isoprene oxidized by NO₃ was comparable to and correlated with the organic aerosol loading for flights with relatively low organic aerosol background. The contribution of nocturnal isoprene oxidation to secondary organic aerosol was determined in the range 1–17%, and isoprene SOA mass derived from NO₃ was calculated to exceed that due to OH by approximately 50%. Aldener, M., Brown, S. S., Stark, H., Williams, E. J., Lerner, B. M., Kuster, W. C., Goldan, P. D., Quinn, P. K., Bates, T. S., Fehsenfeld, F. C., and Ravishankara, A. R.: Reactivity and loss mechanisms of NO₃ and N₂O$_5$ in a marine environment: results from in-situ measurements during NEAQS 2002, J. Geophys. Res., 111, D23S73, doi:10.1029/2006JD007252, 2006. Allan, B. J., McFiggans, G., Plane, J. M. C., Coe, H., and McFadyen, G. G.: The nitrate radical in the remote marine boundary layer, J. Geophys. Res., 105, 24191–24204, 2000. Altieri, K. E., Carlton, A. G., Lim, H.-J., Turpin, B. J., and Seitzinger, S. P.: Evidence for oligomer formation in clouds: Reaction of isoprene oxidation products, Environ. Sci. Technol., 40, 4956–4960, 2006. Ambrose, J. L., Mao, H., Mayne, H. R., Stutz, J., Talbot, R., and Sive, B. C.: Nighttime nitrate radical chemistry at Appledore Island, Maine during the 2004 International Consortium for Atmospheric Research on Transport and Transformation, J. Geophys. Res., 112, D21302, doi:10.1029/2007JD008756, 2007. Apel, E., Riemer, D. D., Hills, A., Baugh, W., Orlando, J., Faloona, I., Tan, D., Brune, W., Lamb, B., Westberg, H., Carroll, M. A., Thornberry, T., and Geron, C.: Measurement and interpretation of isoprene fluxes and isoprene, methacrolein, and methyl vinyl ketone mixing ratios at the PROPHET site during the 1998 Intensive, J. Geophys. Res., 107, 4034, doi:10.1029/2000JD000225, 2002. Atkinson, R. and Arey, J.: Gas-phase tropospheric chemistry of biogenic volatile organic compounds: a review, Atmos. Environ., 37, S197–S219, 2003. Barnes, I., Bastian, V., Becker, K. H., and Tong, Z.: Kinetics and Products of the Reactions of NO₃ with Monoalkenes, Dialkenes, and Monoterpenes, J. Phys. Chem., 94, 2413–2419, 1990. Bench, G., Fallon, S., Schichtel, B., Malm, W., and McDade, C.: Relative contributions of fossil and contemporary carbon sources to PM$_2.5$ aerosols at nine Interagency Monitoring for Protection of Visual Envioronments (IMPROVE) network sites, J. Geophys. Res., 112, D10205, doi:10.1029/2006JD007708, 2007. Berndt, T. and Boge, O.: Gas-phase reaction of NO₃ radicals with isoprene: A kinetic and mechanistic study, Int. J. Chem. Kinet., 29, 755–765, 1997. Biesenthal, T., Bottenheim, J. W., Shepson, P. B., Li, S. M., and Brickell, P. C.: The chemistry of biogenic hydrocarbons at a rural site in eastern Canada, J. Geophys. Res., 103, 25487–25498, 1998. Brown, S. S., Stark, H., and Ravishankara, A. R.: Applicability of the Steady-State Approximation to the Interpretation of Atmospheric Observations of NO₃ and N₂O$_5$, J. Geophys. Res., 108, D174539, doi:10.1029/2003JD003407, 2003. Brown, S. S., Dibb, J. E., Stark, H., Aldener, M., Vozella, M., Whitlow, S., Williams, E. J., Lerner, B. M., Jakoubek, R., Middlebrook, A. M., DeGouw, J. A., Warneke, C., Goldan, P. D., Kuster, W. C., Angevine, W. M., Sueper, D. T., Quinn, P. K., Bates, T. S., Meagher, J. F., Fehsenfeld, F. C., and Ravishankara, A. R.: Nighttime removal of NO_x in the summer marine boundary layer, Geophys. Res. Lett., 31, L07108, doi:10.1029/2004GL019412, 2004. Brown, S. S., Neuman, J. A., Ryerson, T. B., Trainer, M., Dubé, W. P., Holloway, J. S., Warneke, C., de Gouw, J. A., Donnelly, S. G., Atlas, E., Matthew, B., Middlebrook, A. M., Peltier, R., Weber, R. J., Stohl, A., Meagher, J. F., Fehsenfeld, F. C., and Ravishankara, A. R.: Nocturnal odd-oxygen budget and its implications for ozone loss in the lower troposphere, Geophys. Res. Lett., 33, L08801, doi:10.1029/2006GL025900, 2006a. Brown, S. S., Ryerson, T. B., Wollny, A. G., Brock, C. A., Peltier, R., Sullivan, A. P., Weber, R. J., Dubé, W. P., Trainer, M., Meagher, J. F., Fehsenfeld, F. C., and Ravishankara, A. R.: Variability in nocturnal nitrogen oxide processing and its role in regional air quality, Science, 311, 67–70, 2006b. Brown, S. S., Dubé, W. P., Osthoff, H. D., Stutz, J., Ryerson, T. B., Wollny, A. G., Brock, C. A., Warneke, C., de Gouw, J. A., Atlas, E., Neuman, J. A., Holloway, J. S., Lerner, B. M., Williams, E. J., Kuster, W. C., Goldan, P. D., Angevine, W. M., Trainer, M., Fehsenfeld, F. C., and Ravishankara, A. R.: Vertical profiles in NO₃ and N₂O$_5$ measured from an aircraft: Results from the NOAA P-3 and surface platforms during NEAQS 2004, J. Geophys. Res., 112, D22304, doi:10.1029/2007JD008883, 2007. Chen, X., Hulbert, D., and Shepson, P. B.: Measurement of the organic nitrate yield from OH reaction with isoprene, J. Geophys. Res., 103, 25563–25568, 1998. Claeys, M., Graham, B., Vas, G., Wang, W., Vermeylen, R., Pashynska, V., Cafmeyer, J., Guyon, P., Andreae, M. O., Artaxo, P., and Maenhaut, W.: Formation of Secondary Organic Aerosols Trhough Photooxidation of Isoprene, Science, 303, 1173–1176, 2004. de Gouw, J. A., Goldan, P. D., Warneke, C., Kuster, W. C., Roberts, J. M., Marchewka, M., Bertman, S. B., Pszenny, A. A. P., and Keene, W. C.: Validation of proton transfer reaction-mass spectrometry (PTR-MS) measurements of gas-phase organic compounds in the atmosphere during the New England Air Quality Study (NEAQS) in 2002, J. Geophys. Res., 108, D214682, doi:10.1029/2003JD003863, 2003. de Gouw, J. A., Middlebrook, A. M., Warneke, C., Goldan, P. D., Kuster, W. C., Roberts, J. M., Fehsenfeld, F. C., Worsnop, D. R., Canagaratna, M. R., Pszenny, A. A. P., Keene, W. C., Marchewka, M., Bertman, S. B., and Bates, T. S.: Budget of organic carbon in a polluted atmosphere: Results from the New England Air Quality Study in 2002, J. Geophys. Res.-Atmos., 110, D16305, doi:10.1029/2004JD005623, 2005. de Gouw, J. A., Brock, C. A., Atlas, E., Bates, T. S., Fehsenfeld, F. C., Goldan, P. D., Holloway, J. S., Kuster, W. C., Lerner, B. M., Matthew, B. M., Middlebrook, A. M., Onasch, T. B., Peltier, R. E., Quinn, P. K., Senff, C. J., Stohl, A., Sullivan, A. P., Trainer, M., Warneke, C., Weber, R. J., and Williams, E. J.: Sources of particulate matter in the northeastern United States in summer: 1. Direct emission and secondary formation of organic matter in urban plumes, J. Geophys. Res., 113, D08301, doi:10.1029/2007JD009243, 2008. Dubé, W. P., Brown, S. S., Osthoff, H. D., Nunley, M. R., Ciciora, S. J., Paris, M. W., McLaughlin, R. J., and Ravishankara, A. R.: Aircraft instrument for simultaneous, in-situ measurements of NO₃ and N₂O$_5$ via cavity ring-down spectroscopy, Rev. Sci. Instrum., 77, 034101, doi:10.1063/1061.2176058, 2006. Ervens, B., Carlton, A. G., Turpin, B. J., Altieri, K. E., Kreidenwies, S. M., and Feingold, G.: Secondary organic aerosol yields from cloud-processing of isoprene oxidation products, Geophys. Res. Lett., 35, L02816, doi:10.1029/2007GL031828, 2008. Fan, F. and Zhang, R.: Atmospheric Oxidation Mechanism of Isoprene, Environ. Chem., 1, 140–149, 2004. Fehsenfeld, F. C., Ancellet, G., Bates, T. S., Goldstein, A. H., Hardesty, R. M., Honrath, R., Law, K., Lewis, A. C., Leaitch, R., McKeen, S. A., Meagher, J., Parrish, D. D., Pszenny, A. A. P., Russel, P. B., Schlager, H., Seinfeld, J. H., Talbot, R., and Zbinden, R.: International Consortium for Atmospheric Research on Transport and Transformation (ICARTT): North America to Europe – Overview of the 2004 summer field study, J. Geophys. Res., 111, D23S01, doi:10.1029/2006JD007829, 2006. Fischer, R. G., Kaster, J., and Ballschmitter, K.: Levels and pattern of alkyl nitrates, multifunctional alkyl nitrates, and halocarbons in the air over the Atlantic Ocean, J. Geophys. Res., 105, 14473–14494, 2000. Fry, J. L., Kiendler-Scharr, A., Rollins, A. W., Wooldridge, P. J., Brown, S. S., Fuchs, H., Dube, W., Mensah, A., dal Maso, M., Tillmann, R., Dorn, H.-P., Brauers, T., and Cohen, R. C.: Organic nitrate and secondary organic aerosol yield from NO₃ oxidation of β-pinene evaluated using a gas-phase kinetics/aerosol partitioning model, Atmos. Chem. Phys. Discuss., 8, 18039–18089, 2008. Fuentes, J. D., Lerdau, M., Atkinson, R., Baldocchi, D., Bottenheim, J. W., Ciccioli, P., Lamb, B., Geron, C., Gu, L., Guenther, A., Sharkey, T. D., and Stockwell, W.: Biogenic Hydrocarbons in the Atmospheric Boundary Layer: A Review, Bull. Am. Meteorol. Soc., 81, 1537–1575, 2000. Geyer, A., Ackermann, R., Dubois, R., Lohrmann, B., Müller, R., and Platt, U.: Long-term observation of nitrate radicals in the continental boundary layer near Berlin, Atmos. Environ., 35, 3619–3631, 2001. Geyer, A. and Platt, U.: Temperature dependence of the NO₃ loss frequency: A new indicator for the contribution of NO₃ to the oxidation of monoterpenes and NO_x removal in the atmosphere, J. Geophys. Res., 107, D214431, doi: 10.1029/2001JD001215, 2002. Giacopelli, P., Ford, K., Espada, C., and Shepson, P. B.: Comparison of the measured and simulated isoprene nitrate distributions above a forest canopy, J. Geophys. Res., 110, D01304, doi:10.1029/2004JD005123, 2005. Grossenbacher, J. W., Couch, T., Shepson, P. B., Thornberry, T., Witmer-Rich, M., Carroll, M. A., Faloona, I., Tan, D., Brune, W., Ostling, K., and Bertman, S.: Measurements of isoprene nitrates above a forest canopy, J. Geophys. Res., 106, 24429–24438, 2001. Grossenbacher, J. W., Barket, D. J., Shepson, P. B., Carroll, M. A., Olszyna, K., and Apel, E.: A comparison of isoprene nitrate concentrations at two forest-impacted sites, J. Geophys. Res., 109, D11311, doi:10.1029/2003JD003966, 2004. Guenther, A., Karl, T., Harley, P., Wiedinmyer, C., Palmer, P. I., and Geron, C.: Estimates of global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols from Nature), Atmos. Chem. Phys., 6, 3181–3210, 2006. Hallquist, M., Wängberg, I., Ljungstrom, E., Barnes, I., and Becker, K. H.: Aerosol and Product Yields from NO₃ Radical-Initiated Oxidation of Selected Monoterpenes, Environ. Sci. Technol., 33, 553–559, 1999. Henze, D. K. and Seinfeld, J. H.: Global secondary organic aerosol from isoprene oxidation, Geophys. Res. Lett., 33, L09812, doi:10.1029/2006GL025976, 2006. Horowitz, L. W., Fiore, A. M., Milly, G. P., Cohen, R. C., Perrin, A., Wooldridge, P. J., Hess, P. G., Emmons, L. K., and Lamarque, J. F.: Observational constraints on the chemistry of isoprene nitrates over the eastern United States, J. Geophys. Res., 112, D12S08, doi:10.1029/2006JD007747, 2007. Hurst, J. M., Barket, D. J., Herrera-Gomez, O., Couch, T. L., Shepson, P. B., Faloona, I., Tan, D., Brune, W., Westberg, H., Lamb, B., Biesenthal, T., Young, V., Goldstein, A., Munger, J. W., Thornberry, T., and Carroll, M. A.: Investigation of the nighttime decay of isoprene, J. Geophys. Res.-Atmos., 106, 24335–24346, 2001. Kim, S.-W., Heckel, A., McKeen, S. A., Frost, G. J., Hsie, E. Y., Trainer, M. K., Richter, A., Burrows, J. P., Peckham, S. E., and Grell, G. A.: Satellite-observed US power plant NO_x emission reductions and their impact on air quality, Geophys. Res. Lett., 33, L22812, doi:10.1029/2006GL027749, 2006. Kleindienst, T. E., Lewandowski, M., Offenberg, J. H., Jaoui, M., and Edney, E. O.: Ozone-isoprene reaction: Re-examination of the formation of secondary organic aerosol, Geophys. Res. Lett., 34, L01805, doi:10.1029/2006GL027485, 2007. Kroll, J. H., Ng, N. L., Murphy, S. M., Flagan, R. C., and Seinfeld, J. H.: Secondary organic aerosol formation from isoprene photooxidation under high-NO_x conditions, Geophys. Res. Lett., 32, L18808, doi:10.1029/2005GL023637, 2005. Kwok, E. S. C., Aschmann, S. M., Arey, J., and Atkinson, R.: Product formation from the reaction of the NO₃ radical with isoprene and rate constants for the reactions of methacrolein and methyl vinyl ketone with the NO₃ radical, Int. J. Chem. Kinet., 28, 925–934, 1996. Lelieveld, J., Butler, T. M., Crowley, J. N., Dillon, T. J., Fischer, H., Ganzveld, L., Harder, H., Lawrence, M. G., Martinez, M., Taraborrelli, D., and Williams, J.: Atmospheric oxidation capacity sustained by a tropical forest, Nature, 452, 737–740, 2008. Liggio, J., Li, S.-M., Brook, J. R., and Mihele, C. M.: Direct polymerization of isoprene and a-pinene on acidic aerosols, Geophys. Res. Lett., 34, L05814, doi:10.1029/2006GL028468, 2007. McLaren, R., Salmon, R. A., Liggio, J., Hayden, K. L., Analuf, K., and Leaitch, W. R.: Nighttime chemistry at a rural site in the Lower Fraser Valley, Atmos. Environ., 38, 5837–5848, 2004. Neuman, J. A., Huey, L. G., Dissly, R. W., Fehsenfeld, F. C., Flocke, F., Holecek, J. C., Holloway, J. S., Hübler, G., Jakoubek, R., Nicks, D. K., Jr., Parrish, D. D., Ryerson, T. B., Sueper, D. T., and Weinheimer, A. J.: Fast-response airborne in situ measurements of HNO₃ during the Texas 2000 Air Quality Study, J. Geophys. Res., 107, 4436, doi:10.1029/2001JD001437, 2002. Neuman, J. A.: Reactive nitrogen transport and photochemistry in urban plumes over the North Atlantic Ocean, J. Geophys. Res., 111, D23S54, doi:10.1029/2005JD007010, 2006. Ng, N. L., Kwan, A. J., Surratt, J. D., Chan, A. W. H., Chhabra, P. S., Sorooshian, A., Pye, H. O. T., Crounse, J. D., Wennberg, P. O., Flagan, R. C., and Seinfeld, J. H.: Secondary organic aerosol (SOA) formation from reaction of isoprene with nitrate radicals (NO₃), Atmos. Chem. Phys., 8, 4117–4140, 2008. Olivier, J. G. J. and Berdowski, J. J. M.: Global emissions sources and sinks, in: The Climate System, edited by: Berdowski, J., Guicherit, R., and Heij, B. J., A. A. Balkema, The Netherlands, 33–78, 2001. Paulson, S. E. and Seinfeld, J. H.: Development and Evaluation of a Photooxidation Mechnaism for Isoprene, J. Geophys. Res., 97, 20703–20715, 1992. Platt, U. F., Winer, A. M., Bierman, H. W., Atkinson, R., and Pitts Jr., J. N.: Measurement of Nitrate Radical Concentrations in Continental Air, Environ. Sci. Technol., 18, 365–369, 1984. Poisson, N., Kanakidou, M., and Crutzen, P. J.: Impact of Non-Methane Hydrocarbons on Tropospheric Chemistry and the Oxidizing Power of the Global Troposphere: 3-Dimensional Modelling Results, J. Atmos. Chem., 36, 157–230, 2000. Quinn, P. K., Bates, T. S., Coffman, D., Onasch, T. B., Worsnop, D. R., Baynard, T., de Gouw, J. A., Goldan, P. D., Kuster, W. C., Williams, E., Roberts, J. M., Lerner, B. M., Stohl, A., Pettersson, A., and Lovejoy, E. R.: Impacts of sources and aging on submicrometer aerosol prperties in the marine boundary layer across the Gulf of Maine, J. Geophys. Res., 111, D23S36, doi:10.1029/2006JD007582, 2006. Ryerson, T. B., Huey, L. G., Knapp, K., Neuman, J. A., Parrish, D. D., Sueper, D. T., and Fehsenfeld, F. C.: Design and initial characterization of an inlet for gas-phase NO_y measurements from aircraft, J. Geophys. Res., 104, 5483–5492, 1999. Ryerson, T. B., Williams, E. J., and Fehsenfeld, F. C.: An efficient photolysis system for fast response NO₂ measurements, J. Geophys. Res., 105, 26447–26461, 2000. Schauffler, S. M., Atlas, E., Blake, D. R., Flocke, F., Lueb, R. A., Lee-Taylor, J. M., Stroud, V., and Travnicek, W.: Distributions of brominated organic compounds in the troposphere and lower stratosphere, J. Geophys. Res., 104, 21513–21536, 1999. Schichtel, B., Malm, W. C., Bench, G., Fallon, S., McDade, C. E., Chow, J. C., and Watson, J. G.: Fossil and contemporary fine particulate carbon fractions at 12 rural and urban sites in the United States, J. Geophys. Res., 113, D02311, doi:10.1029/2007JD008605, 2008. Sillman, S., Carroll, M. A., Thornberry, T., Lamb, B. K., Westberg, H., Brune, W. H., Faloona, I., Tan, D., Shepson, P. B., Sumner, A. L., Hastie, D. R., Mihele, C. M., Apel, E. C., Riemer, D. D., and Zika, R. G.: Loss of isoprene and sources of nighttime OH radicals at a rural site in the United States: Results from photochemical models, J. Geophys. Res., 107, 4043, doi:10.1029/2001JD000449, 2002. Skamarock, W. C., Klemp, J. B., Dudhia, J., Gill, D. O., Barker, D. M., Duda, M. G., Huang, X. Y., Wang, W., and Powers, J. G.: A description of the advanced research WRF version~3, National Center for Atmospheric Research Technical Note, NCAR/TN-475+STR, online: http://www.mmm.ucar.edu/wrf/users/docs/arw_v3.pdf, 2008. Skov, H., Hjorth, J., Lohse, C., Jensen, N. R., and Restelli, G.: Products and mechanisms of the reactions of the nitrate racidal (NO₃) with isoprene, 1,3-butadiene and 2,3-dimethyl-1,3,butadiene in air, Atmos. Environ., 26A, 2771–2783, 1992. Skov, H., Benter, T., Schindler, R. N., Hjorth, J., and Restelli, G.: Epoxide Formation in the Reactions of the Nitrate Radical with 2,3-Dimethyl-2-Butene, Cis-2-Butene and Trans-2-Butene and Isoprene, Atmos. Environ., 28, 1583–1592, 1994. Slusher, D. L., Huey, L. G., Tanner, D. J., Flocke, F., and Roberts, J. M.: A thermal dissociation – chemical ionization mass sepctrometry (TD-CIMS) technique for the simultaneous measurement of peroxyacetyl radicals and dinitrogen pentoxide, J. Geophys. Res., 109, D19315, doi:10.1029/2004JD004670, 2004. Sommariva, R., Osthoff, H. D., Brown, S. S., Bates, T. S., Baynard, T., Coffman, D., de Gouw, J. A., Goldan, P. D., Kuster, W. C., Lerner, B. M., Stark, H., Warneke, C., Williams, E. J., Fehsenfeld, F. C., Ravishankara, A. R., and Trainer, M.: Radicals in the marine boundary layer during NEAQS 2004: a model study of day-time and night-time sources and sinks, Atmos. Chem. Phys. Discuss., 8, 16643–16692, 2008. Sprengnether, M. M., Demerjian, K. L., Donahue, N. M., and Anderson, J. G.: Product analysis of the OH oxidation of isoprene and 1,3-butadiene in the presence of NO, J. Geophys. Res., 107, 4268, doi:10.1029/2001JD000716, 2002. Starn, T. K., Shepson, P. B., Bertman, S. B., Reimer, D. D., Zika, R. G., and Olszyna, K.: Nighttime isoprene chemistry at an urban-impacted forest site, J. Geophys. Res., 103, 22437–22447, 1998. Steinbacher, M., Dommen, J., Ordonez, C., Reimann, S., Grüebler, F. C., Staehelin, J., Andreani-Aksoyoglu, S., and Prevot, A. S. H.: Volatile Organic Compounds in the Po Basin. Part B: Biogenic VOCs, J. Atmos. Chem., 51, 293–315, doi:10.1007/s10874-005-3577-0, 2005. Stohl, A., Forster, C., Frank, A., Seibert, P., and Wotawa, G.: Technical note: The Lagrangian particle dispersion model FLEXPART version 6.2, Atmos. Chem. Phys., 5, 2461–2474, 2005. Stroud, C. A., Roberts, J. M., Williams, E. J., Hereid, D., Angevine, W. M., Fehsenfeld, F. C., Wisthaler, A., Hansel, A., Martinez-Harder, M., Harder, H., Brune, W. H., Hoenninger, G., Stutz, J., and White, A. B.: Nighttime isoprene trends at an urban forested site during the 1999 Southern Oxidants Study, J. Geophys. Res., 107, 4291, doi:10.1029/2001JD000959, 2002. Stutz, J., Alicke, B., Ackermann, R., Geyer, A., White, A. B., and Williams, E.: Vertical profiles of NO₃, N₂O₂, O₃, and NO_x in the nocturnal boundary layer: 1. Observations during the Texas Air Quality Study 2000, J. Geophys. Res., 109, D12306, doi:10.1029/2003JD004209, 2004. Sullivan, A. P., Peltier, R. E., Brock, C. A., de Gouw, J. A., Holloway, J. S., Warneke, C., Wollny, A. G., and Weber, R. J.: Airborne measurements of carbonaceous aerosol soluble in water over the northeastern United States: Method development and an investigation into water-soluble organic carbon sources, J. Geophys. Res., 111, D23S46, doi:10.1029/2006JD007072, 2006. Trainer, M., Williams, E. J., Parrish, D. D., Buhr, M. P., Allwine, E. J., Westberg, H. H., Fehsenfeld, F. C., and Liu, S. C.: Models and observations of the impact of natural hydrocarbons on rural ozone, Nature, 329, 705–707, 1987. Trainer, M., Buhr, M. P., Curran, C. M., Fehsenfeld, F. C., Hsie, E. Y., Liu, S. C., Norton, R. B., Parrish, D. D., Williams, E. J., Gandrud, B. W., Ridley, B. A., Shetter, J. D., Allwine, E. J., and Westberg, H. H.: Observations and Modeling of the Reactive Nitrogen Photochemistry at a Rural Site, J. Geophys. Res., 96, 3045–3063, 1991. Tuazon, E. C., Alvarado, A., Aschmann, S. M., Atkinson, R., and Arey, J.: Products of the gas-phase reactions of 1,3-butadiene with OH and NO₃ radicals, Environ. Sci. Technol., 33, 3586–3595, 1999. von Kuhlmann, R., Lawrence, M. G., Pöschl, U., and Crutzen, P. J.: Sensitivities in global scale modeling of isoprene, Atmos. Chem. Phys., 4, 1–17, 2004. Warneke, C., de Gouw, J. A., Goldan, P. D., Kuster, W. C., Williams, E. J., Lerner, B. M., Brown, S. S., Stark, H., Aldener, M., Ravishankara, A. R., Roberts, J. M., Marchewka, M., Bertman, S., Sueper, D. T., McKeen, S. A., Meagher, J. F., and Fehsenfeld, F. C.: Comparison of day and nighttime oxidation of biogenic and anthropogenic VOCs along the New England coast in summer during New Enlgand Air Quality Study 2002, J. Geophys. Res., 109, D10309, doi:10.1029/2003JD004424, 2004. Weber, R. J., Orsini, D., Daun, Y., Lee, Y.-N., Klotz, P. J., and Brechtel, F.: A particle-into-liquid collector for rapid measurement of aerosol bulk chemical composition, Aerosol Sci. Technol., 35, 718–727, 2001. Weber, R. J., Sullivan, A. P., Peltier, R., Russell, A., Yan, B., Zheng, M., de Gouw, J. A., Warneke, C., Brock, C. A., Holloway, J. S., Atlas, E. L., and Edgerton, E.: A study of secondary organic aerosol formation in the anthropogenic-influenced southeastern United States, J. Geophys. Res., 112, D13302, doi:10.1029/2007JD008408, 2007. Werner, G., Kaster, J., Looser, R., and Ballschmitter, K.: Organic Nitrates of Isoprene as Atmospheric Trace Compounds, Angew. Chem. Int. Edit., 38, 1634–1637, 1999. Winer, A. M., Atkinson, R., and Pitts, J. N. J.: Gaseous Nitrate Radical: Possible Nighttime Atmospheric Sink for Biogenic Organic Compounds, Science, 224, 156–158, 1984.