Work

Assessment of MITgcm tidal currents in the context of the ODYSEA mission

Year: 2026

Type: article

Abstract: The accurate representation of tidal currents is essential for understanding coastal circulation and interpreting satellite observations of ocean surface currents. In preparation for the upcoming ODYSEA (Ocean Dynamics and Surface Exchange with the Atmosphere) satellite mission, high-resolution MITgcm (Massachusetts Institute of Technology General Circulation Model) LLC2160 outputs, generated for mission planning, were evaluated for their representation of tidal currents. Tidal currents simulated by MITgcm were evaluated using 106 in-situ current meter records from eight coastal and high-latitude regions, including Alaska, Greenland, the Faroe Islands, Australia, and Svalbard. Tidal constituents were extracted through harmonic analysis and compared using tidal ellipse parameters. Model performance was quantified using the root mean square error (RMSE) of semi-major axis amplitudes and compared with the global barotropic tidal model FES2022. MITgcm reproduces the main spatial patterns and orientations of tidal currents across all study areas. Regional RMSE values range from 1.6 cm s −1 in Svalbard to 13.6 cm s −1 in the eastern United States, corresponding to 15.8%–28.5% of maximum observed tidal current amplitudes. The largest discrepancies occur for the dominant M2 and S2 constituents, with mean RMSEs of 8.85 and 9.55 cm s −1 , respectively. MITgcm generally exhibits larger errors than FES2022 but remains within the correct order of magnitude. These results demonstrate that MITgcm provides a dynamically consistent representation of global tidal currents, despite some amplitude overestimation in regions with complex bathymetry. This validation supports its use for ODYSEA mission preparation and future studies of ocean surface current variability.

Source: Frontiers in Marine Science

DOI: 10.3389/fmars.2026.1759762