Variations in ocean currents, sea ice concentration, and sea surface temperature along the North-East coast of Greenland (NEG-OCEAN)

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Based on remote sensing data the temporal evolution of ocean surface currents at the North Eastcoast of Greenland shall be determined and - together with sea ice concentration and sea surfacetemperature - analyzed in order to provide a basis for studying (together with two bundled projects)the coupling mechanism between ice sheet, ocean, and sea ice.During the last decades the Greenland ice sheets experienced a strongly increased mass loss of icesheets, both due to enhanced surface melting and due to the acceleration of outlet glaciers andhigher ice export rates. Compared to the earlier decades, the conuibution of the Greenland ice sheetto global sea level rise doubled during the last two decades. Melt water changes the thermalstmcture of the ice sheet and influences the basal boundary conditions. In addition, interactionsbetween the glacier tongues and the ocean water have a direct impact on the dynamics of outletglaciers. Warm fjord waters impact subglacial melting and increase the ice flux. Conversely, theincrease of fresh water flux into the coastal sea su^ongly influences the water and energy ü-ansportalong the coast. The investigation of the feedback mechanisms between the ice sheet, its marinebased outlet glaciers and the ocean circulation in dependence of atmospheric forcing is therefore anextremely important step in understanding the variability of this complex system and itsimplications on a global scale. The present project focuses on the ocean component. A dedicatedprocessing of satellite altimeter data combined with the most recent gravity field models is used toestimate a time series of the dynamic ocean topography which can be transformed into ageostrophic velocity field. Principal component analyses of topography, sea ice concentration andsea surface temperature shall identify the most dominant modes, in order to provide a basis forinvestigating correlation with mass loss of ice sheets and studying the coupling mechanism betweenice sheet, ocean and sea ice.