Journal Article

FZJ-2014-01743

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Suppression of new particle formation from monoterpene oxidation by NO_x

Wildt, J. (Corresponding author)FZJ* ; Mentel, T. F.FZJ* ; Kiendler-Scharr, A.FZJ* ; Hoffmann, T. ; Andres, S.FZJ* ; Ehn, M.FZJ* ; Kleist, E.FZJ* ; Müsgen, P. ; Rohrer, F.FZJ* ; Rudich, Y. ; Springer, M.FZJ* ; Tillmann, R.FZJ* ; Wahner, A.FZJ*

2014
EGU Katlenburg-Lindau

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Please use a persistent id in citations: http://hdl.handle.net/2128/8013  doi:10.5194/acp-14-2789-2014

Abstract: The impact of nitrogen oxides (NOx = NO + NO2) on new particle formation (NPF) and on photochemical ozone production from real plant volatile organic compound (BVOC) emissions was studied in a laboratory setup. At high NOx conditions ([BVOC] / [NOx] < 7, [NOx] > 23 ppb) new particle formation was suppressed. Instead, photochemical ozone formation was observed resulting in higher hydroxyl radical (OH) and lower nitrogen monoxide (NO) concentrations. When [NO] was reduced back to levels below 1 ppb by OH reactions, NPF was observed. Adding high amounts of NOx caused NPF to be slowed by orders of magnitude compared to analogous experiments at low NOx conditions ([NOx] ~300 ppt), although OH concentrations were higher. Varying NO2 photolysis enabled showing that NO was responsible for suppression of NPF. This suggests that peroxy radicals are involved in NPF. The rates of NPF and photochemical ozone production were related by power law dependence with an exponent approaching −2. This exponent indicated that the overall peroxy radical concentration must have been similar when NPF occurred. Thus, permutation reactions of first-generation peroxy radicals cannot be the rate limiting step in NPF from monoterpene oxidation. It was concluded that permutation reactions of higher generation peroxy-radical-like intermediates limit the rate of new particle formation.In contrast to the strong effects on the particle numbers, the formation of particle mass was substantially less sensitive to NOx concentrations. If at all, yields were reduced by about an order of magnitude only at very high NOx concentrations.

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Contributing Institute(s):

1. Pflanzenwissenschaften (IBG-2)
2. Troposphäre (IEK-8)

Research Program(s):

1. 89582 - Plant Science (POF2-89582) (POF2-89582)
2. 233 - Trace gas and aerosol processes in the troposphere (POF2-233) (POF2-233)

Appears in the scientific report 2014

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Database coverage:
; ; ; ; Current Contents - Social and Behavioral Sciences ; JCR ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Thomson Reuters Master Journal List ; Web of Science Core Collection

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