1. Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research; Dep. Atmospheric Environmental Research (IMK-IFU); Kreuzeckbahnstr. 19 82467 Garmisch-Partenkirchen Germany
2. Leibniz Univ. of Hannover, Institute of Soil Science; Herrenhäuserstr. 2 30419 Hannover Germany
3. Forschungszentrum Jülich GmbH; Agrosphere Institute (IBG-3); 52425 Jülich Germany
4. Federal Institute for Geosciences and Natural Resources; Stilleweg 2 30655 Hannover Germany