Global gravity field from recent satellites (DTU15) — Arctic improvements

Abstract

Global marine gravity field modelling using satellite altimetry is currently undergoing huge improvement with the completion of the Jason-1 end-of-life geodetic mission, but particularly with the continuing Cryosat-2 mission. These new satellites provide three times as many geodetic mission altimetric sea surface height observations as ever before. The impact of these new geodetic mission data is a dramatic improvement of particularly the shorter wavelength of the gravity field (10-20 km) which is now being mapped at significantly higher accuracy. The quality of the altimetric gravity field is in many places surpassing the quality of gravity fields derived using non-commercial marine gravity observations. Cryosat-2 provides for the first time altimetry throughout the Arctic Ocean up to 88°N. Here, the huge improvement in marine gravity mapping is shown through comparison with high quality airborne data flown north of Greenland in 2009. An improvement of nearly 50% in terms of standard deviation with the airborne data was found when comparing with older gravity fields such as DTU10 and EGM08, which are the only global marine gravity fields available in the Arctic Ocean north of 80°N.