Mean Sea Surface and ocean circulation in North Atlantic and the Arctic Sea

High resolution Mean Sea Surface (MSS) model and its error estimation over the study region (56 degrees N<phi<82 degrees N, 45 degrees W<lambda<33 degrees E) have been determined to evaluate Mean Dynamic Topography (MDT) in the Fram Strait and adjacent seas. Multiple high-latitude observing satellite radar altimetry data were used to determine a new MSS model that, hereafter, is called NTNU MSS. Sea Surface Height (SSH) values of the NTNU MSS model vary between 15 to 70 m over the study region, and the internal consistency or the quality estimate for the model ranges from 1 to 5 cm. External comparisons have been performed to validate the NTNU model applying available MSS models such as KMSO4, mean and Standard Deviations (SD) of the differences are 1.7 cm and 8.9 cm, respectively. To assess the compatibility of the NTNU MSS model, residual analysis has been carried out relative to geoid and Oceanographic MDT (OMDT) models. Utilizing OCTASO4 geoid and OCCAM MDT models, the SD and mean of the residuals are 13.1 cm and 10.1 cm, respectively. Finally, the surface geostrophic velocities have been computed and compared with the velocities extracted from the OCCAM and KMS04. Differences between the geostrophic velocities derived from the NTNU Synthetic MDT (SMDT) and the OCCAM OMDT are 4.97 and 2.94 cm/s for the mean and SD values.