HR: 11:35h
AN: A52B-05    [Abstracts]
TI: Disjunct Eddy Covariance Measurements of Monoterpene Fluxes From a Norway Spruce Forest Using Proton-Transfer-Reaction Mass Spectrometry
AU: * Wisthaler, A
EM: armin.wisthaler@uibk.ac.at
AF: Institut fuer Ionenphysik, Universitaet Innsbruck, Technikerstrasse 25, Innsbruck, 6020 Austria
AU: Grabmer, W
EM: wolfgang.grabmer@uibk.ac.at
AF: Institut fuer Ionenphysik, Universitaet Innsbruck, Technikerstrasse 25, Innsbruck, 6020 Austria
AU: Graus, M
EM: martin.graus@uibk.ac.at
AF: Institut fuer Ionenphysik, Universitaet Innsbruck, Technikerstrasse 25, Innsbruck, 6020 Austria
AU: Lindinger, C
EM: christian.lindiger@uibk.ac.at
AF: Institut fuer Ionenphysik, Universitaet Innsbruck, Technikerstrasse 25, Innsbruck, 6020 Austria
AU: Rappenglueck, B
EM: brappenglueck@uh.edu
AF: IMK-IFU, Forschungszentrum Karlsruhe GmbH, Kreuzeckbahnstrasse 19, Garm.-Partenkirchen, 82469 Germany
AU: Steinbrecher, R
EM: rainer.steinbrecher@imk.fzk.de
AF: IMK-IFU, Forschungszentrum Karlsruhe GmbH, Kreuzeckbahnstrasse 19, Garm.-Partenkirchen, 82469 Germany
AU: Hansel, A
EM: armin.hansel@uibk.ac.at
AF: Institut fuer Ionenphysik, Universitaet Innsbruck, Technikerstrasse 25, Innsbruck, 6020 Austria
AB: Interest in reliable quantification of organic trace compounds released from terrestrial ecosystems stems from their impact on oxidant levels such as ozone and hydroxyl radicals and on secondary organic aerosol formation. In an attempt to quantify these emissions, a disjunct eddy covariance (DEC) sampling system was coupled to a proton-transfer-reaction mass spectrometer (PTR-MS). In the DEC method, an instantaneous grab sample is taken at intervals of tens of seconds and vertical wind speed at the instant of sample collection is recorded. Intermittent periods are used for sample analysis by a moderately fast chemical sensor, in this case a PTR-MS, which allows for fast and highly sensitive detection of biogenic volatile organic compounds. The vertical turbulent transport of a trace compound is then calculated from the covariance of the fluctuations in vertical wind speed and compound mixing ratio. Fluxes of monoterpenes from a Norway spruce forest were measured during the 2002 summer intensive field campaign of BEWA2000 and results compared well with data obtained using the relaxed eddy accumulation and enclosure approach. In addition to this field experiment, a laboratory test was carried out to validate the disjunct sampling procedure.
DE: 0315 Biosphere/atmosphere interactions
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting