Gravity Changes in Northern Europe as Observed by GRACE
During the mission duration of GRACE (about five years), a temporal geoid change of about 3 mm is expected in the centre of the Fennoscandian land uplift area (the Bothnian Bay), corresponding to a gravity change of about 100 nm/s2. The uplift effect reaches up to 11 mm/year at the Earth’s surface. It can be observed geometrically by GPS, and gravitationally in space by GRACE as well as on the ground by absolute gravimetry. In this study, we determine gravity changes in Northern Europe from the monthly GRACE solutions as provided by CSR, University of Texas, and compare them with recent terrestrial gravity measurements carried out at some selected sites in the region. Each of the gravity data sets is affected by various geophysical processes such as atmospheric, oceanic and hydrological effects which conceal the uplift signal and therefore have to be removed. In this respect, also the processing and filtering of the various data sets is considered.
KeywordsPostglacial rebound GRACE secular and periodic gravity changes absolute gravimetry
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