ARCTIC OCEAN GEOID, ICE THICKNESS AND MEAN SEA LEVEL – THE ARCGICE

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Arctic; Arctic Ocean; Sea ice
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.505.6500; http://www.gfy.ku.dk/~cct/arcgice/725_for.pdf

Satellite altimetry from ERS, Envisat and ICESat may be used together with updated geoid models based on surface, airborne and satellite gravity field data to derive estimates of Arctic Ocean mean dynamic topography (MDT). In the paper we outline the computation of a new Arctic geoid from terrestrial gravity data and GRACE, and study characteristics of the geoid errors based on least-squares collocation. Based on ICESat lowest-level filtered laser altimetry and retracked ERS radar altimetry we construct an Arctic Ocean mean sea surface (MSS), which combined with the geoid model gives an estimate of the MDT. We compare results to oceanographic models, showing that an overall absolute consistency is possible at the dm-level. Arctic Ocean sea ice freeboard heights (and thus thickness) are an integral part of these investigations, and ICESat-derived freeboard heights show a good correlation to multi-year ice distribution as determined from Quikscat. The sea ice presence, which may bias altimetry sea level measurements, as well as the inhomogenous distribution of gravity data and tidal model errors, are limiting factors in the MDT determination.