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UP: Umweltphysik
UP 12: Poster: Neuartige Messverfahren der Umweltphysik
UP 12.4: Poster
Dienstag, 8. März 2005, 10:15–12:15, Poster TU HTF
Flux measurements of biogenic VOCs during ECHO 2003 — •Christoph Spirig1, Albrecht Neftel1, Christof Ammann1, Josef Dommen2, Wolfgang Grabmer3, Axel Thielmann4, Andrea Schaub5, Jonathan Beauchamp3, Armin Wisthaler3, and Armin Hansel3 — 1Agroscope FAL Reckenholz, Zurich, CH — 2Lab. of Atmos. Chem., PSI, Villigen, CH — 3Inst. of Ion Physics, Innsbruck University, AT — 4MPI for Chemistry, Mainz, D — 5ICG, Research Centre Jülich, D
Within the framework of the AFO 2000 project ECHO, two PTR-MS instruments were operated in combination with sonic anemometers to determine biogenic VOC fluxes from a mixed deciduous forest site using the eddy covariance (EC) technique. Isoprene and monoterpenes emissions depended on sunlight and temperature, with average emissions (normalised to 30 ∘ C and 1000 µ moles m−2 PAR) of 1.5 and 0.39 µg m−2 s−1, respectively. Emissions of methanol reached on average 0.087 µg m−2 s−1 during daytime, but fluxes were too small to be detected at night time. Upward fluxes of the isoprene oxidation products methyl vinyl ketone (MVK) and methacrolein (MACR) were also found, being two orders of magnitude lower than those of isoprene. The observed fluxes are consistent with up-scaling from leaf-level emission measurements of representative tree species in this forest and, in the case of MVK and MACR, can plausibly be explained by chemical production through oxidation of isoprene within the canopy.