Biogeosciences
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5
2
2008
10.5194/bg-5-451-2008
http://www.biogeosciences.net/5/451/2008/
http://www.biogeosciences.net/5/451/2008/bg-5-451-2008.html
http://www.biogeosciences.net/5/451/2008/bg-5-451-2008.pdf
451
462
2008-03-26
Quality control of CarboEurope flux data – Part 2: Inter-comparison of eddy-covariance software
M. Mauder
mauderm@agr.gc.ca
T. Foken
R. Clement
J. A. Elbers
W. Eugster
T. Grünwald
B. Heusinkveld
O. Kolle
University of Bayreuth, Department of Micrometeorology, Bayreuth, Germany
University of Edinburgh, Institute of Ecology and Resource Management, Scotland
Alterra, Wageningen University and Research Centre, Wageningen, The Netherlands
ETH Zurich, Institute of Plant Sciences, Zurich, Switzerland
Technische Universität Dresden, Institute of Hydrology and Meteorology, Dresden, Germany
Wageningen University, Department of Meteorology and Air Quality, Wageningen, The Netherlands
Max-Planck-Institute for Biogeochemistry, Jena, Germany
now at: Agriculture and Agri-Food Canada Research Branch, Ottawa, Ontario, Canada
As part of the quality assurance and quality control activities within the
CarboEurope-IP network, a comparison of eddy-covariance software was
conducted. For four five-day datasets, CO<sub>2</sub> flux estimates were
calculated by seven commonly used software packages to assess the
uncertainty of CO<sub>2</sub> flux estimates due to differences in
post-processing. The datasets originated from different sites representing
different commonly applied instrumentation and different canopy structures
to cover a wide range of realistic conditions. Data preparation, coordinate
rotation and the implementation of the correction for high frequency
spectral losses were identified as crucial processing steps leading to
significant discrepancies in the CO<sub>2</sub> flux results. The overall
comparison indicated a good although not yet perfect agreement among the
different software within 5–10% difference for 30-min CO<sub>2</sub> flux
values. Conceptually different ideas about the selection and application of
processing steps were a main reason for the differences in the CO<sub>2</sub> flux
estimates observed. A balance should be aspired between scientific freedom
on the one hand, in order to advance methodical issues, and standardisation
of procedures on the other hand, in order to obtain comparable fluxes for
multi-site synthesis studies.
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