The Earth’s Temporal Gravity Field Observed By GOCE

Abstract:

GOCE is the European Space Agency’s satellite gravity mission launched on 17 March 2009 providing continuous data from November 2009 until October 2013 with the exception of a few data gaps caused by instrument anomalies. The orbit and instrumental measurement of the GOCE satellite mission offer the highest ever resolution capabilities for mapping Earth’s gravity field from space. GOCE was designed to determine the Earth’s mean gravity field, and it was not anticipated that it could observe temporal gravity field variations. Nevertheless, GOCE may be sensitive to temporal gravity field variations because of its dense track coverage and because its low orbit with a nominal perigee height of 255 km. We will show that GOCE is sensitive to trends in ice mass balance of the West Antarctic Ice Sheet and to a certain extent also to those of the Greenland Ice Sheet and glaciers in Alaska. In addition, we show that GOCE is sensitive to the megathrust Tohoku-Oki 2011 earthquake and probably also to the Chile-Maule 2010 earthquake. The added value of GOCE with respect to GRACE will be discussed.