HuangOCEAN02/CVTM: Cape Verde Tide Model

Motivation Understanding tide–topography interactions and their contribution to mixing is essential for assessing the role of tidal dynamics in driving upward nutrient supply in the North Atlantic Eastern Boundary Upwelling region. The Cape Verde Tide Model (CVTM) is aimed at reproducing the baroclinic tides within the Cape Verde and Eastern Boundary Upwelling regions. A new version of the ORCTM (ORCTM v2.0.0) The CVTM is based on the Oceanic Regional Circulation and Tide model version 1.0 (Huang et al., 2024). It solves the three-dimensional, fully nonlinear primitive equations on a horizontal Arakawa-C grid and in Z-coordinates. The model domain, spanning from 27°W to 13.4°W and from 9.3°N to 18.3°N, covers the eastern boundary upwelling region off Northwest Africa and the Cape Verde archipelago at 1/60° horizontal resolution. Model bathymetry is based on the SRTM15+ V2.1 global bathymetry and topography dataset (Tozer et al., 2019). The vertical grid is the same as that used by Song and Chen (2020). It is configured to simulate the features and subtleties of internal tide formation, propagation, and dissipation in the eastern boundary upwelling region off Northwest Africa including the Cape Verde Sea area. The model results have been systematically validated via satellite altimeter, tide gauges, and mooring sites. Model Configuration This model is initialized using a horizontally homogeneous stratification based on the spatially averaged stratification in the CVA extracted from the World Ocean Atlas 2023 data (Reagan et al., 2024). There are no wind and buoyancy forcing processes at the surface, i.e. the surface wind stress, and the surface heat and freshwater fluxes are set to zero. Tide forcing in the CVTM is applied using the sponge relaxation boundary treatment within a width of 30 grid points. Eight primary barotropic tide constituents (M2, S2, N2, K2, O1, K1, P1, and Q1) are extracted from the TPXO9-atlas regional solution in the West Africa Coastal area (Egbert & Erofeeva, 2002) from July to August in 2011 and are used to drive the model. References Egbert, G. D., & Erofeeva, S. Y. (2002). Efficient inverse modeling of barotropic ocean tides. Journal of Atmospheric and Oceanic Technology, 19, 183–204. doi.org)019<0183:EIMOBO>2.0.CO;2 Huang, H., Song, P., Qiu, S., Guo, J., & Chen, X. (2023). A nonhydrostatic oceanic regional model, ORCTM v1, for internal solitary wave simulation. Geoscientific Model Development, 16(1), 109–133. doi.org Reagan, J. R., Boyer, T. P., García, H. E., Locarnini, R. A., Baranova, O. K., Bouchard, C., Cross, S. L., Mishonov, A. V., Paver, C. R., Seidov, D., Wang, Z., & Dukhovskoy, D. (2024). World Ocean Atlas 2023 [Dataset]. NOAA National Centers for Environmental Information. NCEI Accession 0270533 Song, P., & Chen, X. (2020). Investigation of the internal tides in the Northwest Pacific Ocean considering the background circulation and stratification. Journal of Physical Oceanography, 50(11), 3165-3188. doi.org Tozer, B., Sandwell, D. T., Smith, W. H. F., Olson, C., Beale, J. R., & Wessel, P. (2019). Global bathymetry and topography at 15 arc sec: SRTM15+. Earth and Space Science, 6(10), 1847-1864. doi.org Full Changelog: github.com