Comparison of Altimetric and Ship borne Marine Gravity over Ice-free and Ice-covered polar Seas

Various recent marine altimetric gravity fields based on geodetic mission altimetry are compared with ship borne gravity in four regions around Greenland. This is done over different states of the ocean surface ranging from ice free open ocean to permanently ice covered ocean. Distinguishing between results obtained over these different states is important because, usually, the accuracy of the altimetric products decreases with increasing coverage of ice and proximity to coast.