Surface Topographic Changes in Southern Greenland, 2003-2011, Measured Using Space and Airborne Lidar Remote Sensing

Airborne laser mapping has numerous applications in Earth science including providing topographic information of ice surfaces for mass balance investigations and dynamical modeling. In April 2011, NASA's Land, Vegetation and Ice Sensor (LVIS) system imaged areas of Greenland as part of NASA's Operation IceBridge on board a KingAir B-200 aircraft from NASA Langley. LVIS is an airborne, medium-footprint (~25 m diameter), wide swath (~2 km) full waveform recording lidar system that has been used extensively for mapping surface structure. The system digitally records the shape of the outgoing and returning laser echo, or waveform which, after its interaction with the various reflecting surfaces of the earth, provides a true 3-dimensional record of the surface structure within each footprint in the data swath. During the mission, over 50,000 km2 of data were collected in the southwest quadrant of Greenland along grid lines offset from each other by 5 km, 10 km or 20 km, oriented along elevation contours, and following ICESat tracks where possible. The data provides a comprehensive topographic sampling of the area to achieve the Icebridge vision of fuller utilization of the ICESat legacy data set and continuing surface elevation change measurements between spaceborne missions. Comparisons to ICESat elevation data are presented to quantify surface changes since 2003 in the area. Up to 6 m of elevation loss over large spatial areas was observed from 2003-2011, extending at least 200 km inland. Comparisons of the magnitude and spatial patterns of change will be made and compared to other methods including GRACE.