Variations of ice sheet geometry, ice flow, and mass distribution in Northeast Greenland in the context of oceanic and atmospheric interactions

• Antragstellerinnen / Antragsteller: Professor Dr. Michael Eineder; Dr. Dana Floricioiu; Professor Dr.-Ing. Martin Horwath; Professor Dr. Roland Pail
• Fachliche Zuordnung: Geodäsie, Photogrammetrie, Fernerkundung, Geoinformatik, Kartographie
• Förderung: Förderung von 2014 bis 2018
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 237883478

The Greenland ice sheet has experienced increasing rates of mass loss during the last decade, both due to enhanced surface melt and due to acceleration of outlet glaciers. A major control on ice flow variations is through interactions with ocean water: Warm water in fjords and underneath ice tongues can strongly increase ice melt and iceberg calving at the ice-water interface, triggering an acceleration of ice flow. However, the mechanisms and causalities of ice sheet-ocean-atmosphere interactions are not yet fully understood. So far, the northeastern part of the Greenland ice sheet has not seemed to be strongly affected by climate-related changes. Further changes in the climatic system, however, will likely switch the conditions into a more unstable mode. Here, we are in the fortunate situation to start investigations already before major changes occur. This project is part of the bundle "The linked ice sheet-ocean-atmosphere system in Northeast Greenland and its sensitivity". The three bundle projects jointly aim at understanding the mentioned linked system. While the two companion projects address, respectively, observations of time-variable ocean dynamics and modeling studies of the ice sheet-ocean-atmosphere coupling, the present project is dedicated to observations of the land ice side of the coupled system. The state and the changes of ice sheet geometry, ice flow and ice mass in the northeastern part of the Greenland ice sheet shall be determined using geodetic and remote sensing data. A new quality and comprehensiveness of the results shall be attained by using novel sensors, by synthesizing complementary observations and modeling, and by extending time series to the present. For changes in ice sheet geometry, satellite altimetry will be the main data source. The potential of the CryoSat-2 radar altimeter over ice sheet margins will be explored. Locally, airborne altimetry and satellite remote sensing will be additionally employed. Flow velocity fields will be derived by SAR interferometry as well as feature tracking (SAR and optical images), in order to complement and continue available flow velocity information. The remote sensing focus is on the new, high-resolution TerraSAR-X and TanDEM-X satellite missions. Direct estimates of mass changes are derived from GRACE satellite gravimetry using new time-variable solutions with enhanced accuracy. A combined data analysis shall not only take advantage from the complementarity of the involved observations, but also include physical insights from the companion bundle projects, in order to deliver products that, in turn, serve as boundary conditions and validation basis for modeling studies within the bundle.

• DFG-Verfahren: Sachbeihilfen