Umweltmeteorologie Environmental Meteorology A scheme for assessment of quality and uncertainty for long-term eddy-covariance measurements Clemens Drüe 3 , M. Mauder 1 , M. Cuntz 2 , A. Graf 4 , C. Rebmann 2 , H. P. Schmid 1 , M. Schmidt 4 , and R. Steinbrecher 1 1 Institute for Meteorology and Climatology – Atmospheric Environmental Research (IMK-IFU), Karlsruhe Institute of Technology (KIT), Garmisch-Partenkirchen, Germany 2 UFZ – Helmholtz Centre for Environmental Research, Leipzig, Germany 3 Trier University, Environmental Meteorology, Trier, Germany 4 Forschungszentrum Jülich, Institute for Bio- and Geosciences – Agrosphere, Jülich, Germany