Articles | Volume 5, issue 2
Biogeosciences, 5, 433–450, 2008
Biogeosciences, 5, 433–450, 2008

  26 Mar 2008

26 Mar 2008

Quality control of CarboEurope flux data – Part 1: Coupling footprint analyses with flux data quality assessment to evaluate sites in forest ecosystems

M. Göckede1,*, T. Foken1, M. Aubinet2, M. Aurela3, J. Banza4, C. Bernhofer5, J. M. Bonnefond6, Y. Brunet6, A. Carrara7, R. Clement8, E. Dellwik9, J. Elbers10, W. Eugster11, J. Fuhrer12, A. Granier13, T. Grünwald5, B. Heinesch2, I. A. Janssens14, A. Knohl15,16, R. Koeble17, T. Laurila3, B. Longdoz13, G. Manca17, M. Marek18, T. Markkanen1,19, J. Mateus20, G. Matteucci21, M. Mauder1,**, M. Migliavacca22, S. Minerbi23, J. Moncrieff8, L. Montagnani23, E. Moors10, J.-M. Ourcival24, D. Papale25, J. Pereira26, K. Pilegaard9, G. Pita20, S. Rambal24, C. Rebmann15, A. Rodrigues27, E. Rotenberg28, M. J. Sanz7, P. Sedlak29, G. Seufert17, L. Siebicke1, J. F. Soussana30, R. Valentini25, T. Vesala19, H. Verbeeck14,***, and D. Yakir28 M. Göckede et al.
  • 1University of Bayreuth, Dept. of Micrometeorology, Bayreuth, Germany
  • 2University of Agricultural Sciences, Unit of Biosystems Physic, Gembloux, Belgium
  • 3Finnish Meteorological Institute, Helsinki, Finland
  • 4University of Evora, Evora, Portugal
  • 5Technische Universität Dresden, Inst. of Hydrology and Meteorology, Dept. of Meteorology, Tharandt, Germany
  • 6INRA, EPHYSE, Bordeaux, France
  • 7Foundation CEAM, Valencia, Spain
  • 8University of Edinburgh, School of GeoSciences, Edinburgh, UK
  • 9Technical University of Denmark, Risø National Laboratory, Roskilde, Denmark
  • 10Alterra, Wageningen, The Netherlands
  • 11ETH Zurich, Institute of Plant Sciences, Zurich, Switzerland
  • 12Agroscope Research Station ART, Air Pollution/Climate Group, Zurich, Switzerland
  • 13INRA, Centre INRA Nancy, UMR1137 Ecologie et Ecophysiologie Forestières, Champenoux, France
  • 14University of Antwerpen, Dept. of Biology, Research Group of Plant and Vegetation Ecology, Wilrijk, Belgium
  • 15Max Planck Institute for Biogeochemistry, Jena, Germany
  • 16ETH Zurich, Institute of Plant Sciences, Zurich, Switzerland
  • 17JRC, Inst. for Environment and Sustainability, Ispra, Italy
  • 18Institute of Systems Biology and Ecology AS CR, České Budějovice, Czech Republic
  • 19University of Helsinki, Dept. of Physical Sciences, Helsinki, Finland
  • 20Instituto Superior Tecnico, Lisbon, Portugal
  • 21CNR-ISAFOM, Institute for Mediterranean Agricultural and Forest Systems, Rende, Italy
  • 22Remote Sensing of Environmental Dynamics Lab., DISAT-UNIMIB, Milan, Italy
  • 23Forest Department, Agency for the Environment, Autonomous Province of Bolzano-South Tyrol, Italy
  • 24INRA, DREAM CEFE-CNRS, Montpellier, France
  • 25University of Tuscia, Dept. of Forest Environment and Resources, Viterbo, Italy
  • 26Instituto Superior de Agronomia, Lisbon, Portugal
  • 27Estação Florestal Nacional, Oeiras, Portugal
  • 28Weizman Institute of Science, Dept. of Environmental Sciences and Energy Research, Rehovol, Israel
  • 29Institute of Atmospheric Physics AS CR, Praha, Czech Republic
  • 30INRA, Institut National de la Recherche Agronomique, Paris, France
  • *now at: Oregon State University, Dept. of Forest Science, Corvallis, USA
  • **now at: Agriculture and Agri-Food Canada, Research Branch, Ottawa, Canada
  • ***now at: Laboratory of Climate Sciences and the Environment (LSCE), Joint Unit of CEA-CNRS, Gif-sur-Yvette, France

Abstract. We applied a site evaluation approach combining Lagrangian Stochastic footprint modeling with a quality assessment approach for eddy-covariance data to 25 forested sites of the CarboEurope-IP network. The analysis addresses the spatial representativeness of the flux measurements, instrumental effects on data quality, spatial patterns in the data quality, and the performance of the coordinate rotation method. Our findings demonstrate that application of a footprint filter could strengthen the CarboEurope-IP flux database, since only one third of the sites is situated in truly homogeneous terrain. Almost half of the sites experience a significant reduction in eddy-covariance data quality under certain conditions, though these effects are mostly constricted to a small portion of the dataset. Reductions in data quality of the sensible heat flux are mostly induced by characteristics of the surrounding terrain, while the latent heat flux is subject to instrumentation-related problems. The Planar-Fit coordinate rotation proved to be a reliable tool for the majority of the sites using only a single set of rotation angles. Overall, we found a high average data quality for the CarboEurope-IP network, with good representativeness of the measurement data for the specified target land cover types.

Final-revised paper