Temporal Variations from GOCE for Improving Antarctic Ice Mass Trends
Rexer, Moritz1; Pail, Roland1; Horwath, Martin1; Horvath, Alexander1; Fuchs, Martin2
1TU München, Institute of Astronomical and Physical Geodesy, GERMANY; 2DGFI, GERMANY
Recent observations show evidence for rapid and dramatic environmental changes of the West Antarctic ice sheet. Accelerated flow of outlet glaciers has been associated with thinning of ice shelves, suggesting that ice shelves play an important role in stabilising or restraining ice motion. The GRACE satellite gravity mission has dramatically improved our knowledge on ice sheet changes, including West Antarctica. However, ice mass trend estimates as derived from GRACE are limited to a few 100 km spatial wavelengths. In this contribution the potential of the GOCE mission to observe time variable signal shall be investigated on the basis of global GOCE gravity field models derived from multi-year gravity gradient data, with special emphasis on the Western Antarctic region. They shall be combined consistently with GRACE data, taking the variance-covariance information of all GOCE observation types into account. Mass changes over ice drainage basins will be determined by adaptation of estimation of estimation approaches used with GRACE solutions, namely the regional integration approach and the forward-modeling approach. The mass change estimates based on combined GOCE+GRACE gravity field solutions shall be compared with those of GRACE-only models, and the impact of GOCE to achieve a higher spatial resolution particularly of trend signals in Western Antarctica shall be analyzed.