TY  - JOUR
AU  - Kiendler-Scharr, A.
AU  - Andres, S.
AU  - Bachner, M.
AU  - Behnke, K.
AU  - Broch, S.
AU  - Hofzumahaus, A.
AU  - Holland, F.
AU  - Kleist, E.
AU  - Mentel, T.F.
AU  - Rubach, F.
AU  - Springer, M.
AU  - Steitz, B.
AU  - Tillmann, R.
AU  - Wahner, A.
AU  - Schnitzler, J.-P.
AU  - Wildt, J.
TI  - Isoprene in poplar emissions: effects on new particle formation and OH concentrations
JO  - Atmospheric chemistry and physics
VL  - 12
SN  - 1680-7316
CY  - Katlenburg-Lindau
PB  - EGU
M1  - PreJuSER-19819
SP  - 1021 - 1030
PY  - 2012
N1  - 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.
AB  - 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.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000300321500027
DO  - DOI:10.5194/acp-12-1021-2012
UR  - https://juser.fz-juelich.de/record/19819
ER  -