HR: 0800h
AN: C11A-0094    [Abstracts]
TI: Estimation of Greenland's Ice Sheet Mass Balance Using ICESat and GRACE Data
AU: * Slobbe, D
EM: D.C.Slobbe@student.tudelft.nl
AF: Delft Institute of Earth Observation and Space Systems, Delft University of Technology, P.O. Box 5058, Delft, 2600 GB, Netherlands
AU: Ditmar, P
EM: P.G.Ditmar@tudelft.nl
AF: Delft Institute of Earth Observation and Space Systems, Delft University of Technology, P.O. Box 5058, Delft, 2600 GB, Netherlands
AU: Lindenbergh, R
EM: R.C.Lindenbergh@lr.tudelft.nl
AF: Delft Institute of Earth Observation and Space Systems, Delft University of Technology, P.O. Box 5058, Delft, 2600 GB, Netherlands
AB: Data of the GRACE gravity mission and the ICESat laser altimetry mission are used to create two independent estimates of Greenland's ice sheet mass balance over the full measurement period. For ICESat data, a processing strategy is developed using the elevation differences of geometrically overlapping footprints of both crossing and repeated tracks. The dataset is cleaned using quality flags defined by the GLAS science team. The cleaned dataset reveals some strong, spatially correlated signals that are shown to be related to physical phenomena. Different processing strategies are used to convert the observed temporal height differences to mass changes for 6 different drainage systems, further divided into a region above and below 2000 meter elevation. The results are compared with other altimetry based mass balance estimates. In general, the obtained results confirm trends discovered by others, but we also show that the choice of processing strategy strongly influences our results, especially for the areas below 2000 meter. Furthermore, GRACE based monthly variations of the Earth's gravity field as processed by CNES, CSR, GFZ and DEOS are used to estimate the mass balance change for North and South Greenland. It is shown that our results are comparable with recently published GRACE estimates (mascon solutions). On the other hand, the estimates based on GRACE data are only partly confirmed by the ICESat estimates. Possible explanations for the obvious differences will be discussed.
DE: 0758 Remote sensing
DE: 0762 Mass balance (1218, 1223)
SC: Cryosphere [C]
MN: 2007 Fall Meeting