KLIWAS Seite 38 KLIWAS Climatology of North Sea Fronts AATSR AVHRR frontzone magnitude 2003-2010 total AATSR MODIS AVHRR front20rte_magnitude_total 0025 0 050 0 075 0100 0125 0150 0.175 0 200 0 225 Fig. 28: Mean of gradient magnitude for frontal zone based on the data of the AATSR sensor on ENVISAT, MODIS sensor on AQUA, of the AVHRR sensor on NOAA and METOP 2003 - 2010