%0 Journal Article
%A Rollins, A. W.
%A Kiendler-Scharr, A.
%A Fry, J. L.
%A Brauers, T.
%A Brown, S. S.
%A Dorn, H.-P.
%A Dubé, W. P.
%A Fuchs, H.
%A Mensah, A.
%A Mentel, T. F.
%A Rohrer, F.
%A Tillmann, R.
%A Wegener, R.
%A Wooldridge, P. J.
%A Cohen, R.C.
%T Isoprene oxidation by nitrate radical: alkyl nitrate and secondary organic aerosol yields
%J Atmospheric chemistry and physics
%V 9
%@ 1680-7316
%C Katlenburg-Lindau
%I EGU
%M PreJuSER-5758
%P 6685 - 6703
%D 2009
%Z The Berkeley authors were supported by NSF ATM-0639847 and NSF ATM-0511829. The authors would like to thank the SAPHIR NO<INF>3</INF> intercomparison campaign team for organizing and administering the experiments in June 2007 at Forschungszentrum Julich. This work was a joint activity of the European Community Network of Excellence ACCENT, grant no. GOCE CT-2004-505337 and the EUROCHAMP project.
%X Alkyl nitrates and secondary organic aerosol (SOA) produced during the oxidation of isoprene by nitrate radicals has been observed in the SAPHIR ( Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) chamber. A 16 h dark experiment was conducted with temperatures at 289-301 K, and maximum concentrations of 11 ppb isoprene, 62.4 ppb O-3 and 31.1 ppb NOX. We find the yield of nitrates is 70 +/- 8% from the isoprene + NO3 reaction, and the yield for secondary dinitrates produced in the reaction of primary isoprene nitrates with NO3 is 40 +/- 20%. We find an effective rate constant for reaction of NO3 with the group of first generation oxidation products to be 7 x 10(-14) molecule(-1) cm(3) s(-1). At the low total organic aerosol concentration in the chamber (max=0.52 mu g m(-3)) we observed a mass yield (Delta SOA mass/Delta isoprene mass) of 2% for the entire 16 h experiment. However a comparison of the timing of the observed SOA production to a box model simulation of first and second generation oxidation products shows that the yield from the first generation products was <0.7% while the further oxidation of the initial products leads to a yield of 14% ( defined as Delta SOA/Delta isoprene(2X) where Delta isoprene(2X) is the mass of isoprene which reacted twice with NO3). The SOA yield of 14% is consistent with equilibrium partitioning of highly functionalized C-5 products of isoprene oxidation.
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000270131400003
%U https://juser.fz-juelich.de/record/5758