Journal Article

PreJuSER-19819

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Isoprene in poplar emissions: effects on new particle formation and OH concentrations

Kiendler-Scharr, A.FZJ* ; Andres, S.FZJ* ; Bachner, M.FZJ* ; Behnke, K.FZJ* ; Broch, S.FZJ* ; Hofzumahaus, A.FZJ* ; Holland, F.FZJ* ; Kleist, E.FZJ* ; Mentel, T. F.FZJ* ; Rubach, F.FZJ* ; Springer, M.FZJ* ; Steitz, B.FZJ* ; Tillmann, R.FZJ* ; Wahner, A.FZJ* ; Schnitzler, J.-P. ; Wildt, J.FZJ*

2012
EGU Katlenburg-Lindau

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Please use a persistent id in citations: http://hdl.handle.net/2128/7405  doi:10.5194/acp-12-1021-2012

Abstract: Stress-induced volatile organic compound (VOC) emissions from transgenic Grey poplar modified in isoprene emission potential were used for the investigation of photochemical secondary organic aerosol (SOA) formation. In poplar, acute ozone stress induces the emission of a wide array of VOCs dominated by sesquiterpenes and aromatic VOCs. Constitutive light-dependent emission of isoprene ranged between 66 nmol m(-2) s(-1) in non-transgenic controls (wild type WT) and nearly zero (<0.5 nmol m(-2) s(-1)) in isoprene emission-repressed plants (line RA22), respectively. Nucleation rates of up to 3600 cm(-3) s(-1) were observed in our experiments. In the presence of isoprene new particle formation was suppressed compared to non-isoprene containing VOC mixtures. Compared to isoprene/monoterpene systems emitted from other plants the suppression of nucleation by isoprene was less effective for the VOC mixture emitted from stressed poplar. This is explained by the observed high efficiency of new particle formation for emissions from stressed poplar. Direct measurements of OH in the reaction chamber revealed that the steady state concentration of OH is lower in the presence of isoprene than in the absence of isoprene, supporting the hypothesis that isoprenes' suppressing effect on nucleation is related to radical chemistry. In order to test whether isoprene contributes to SOA mass formation, fully deuterated isoprene (C5D8) was added to the stress-induced emission profile of an isoprene free poplar mutant. Mass spectral analysis showed that, despite the isoprene-induced suppression of particle formation, fractions of deuterated isoprene were incorporated into the SOA. A fractional mass yield of 2.3% of isoprene was observed. Future emission changes due to land use and climate change may therefore affect both gas phase oxidation capacity and new particle number formation.

Keyword(s): J

Note: The work was supported by the German Science Foundation (DFG) (SCHN653/4 to J.-P. S.) within the German joint research group "Poplar - A Model to Address Tree-Specific Questions" and by the European Community's Seventh Framework Programme ([FP7/2007-2013]) EU project PEGASOS under grant agreement no. 265307.

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Contributing Institute(s):

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

Research Program(s):

1. Terrestrische Umwelt (P24)
2. Atmosphäre und Klima (P23)

Appears in the scientific report 2012

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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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