The SSM is an implementation of the Finite Volume Community Ocean Model (FVCOM). FVCOM was developed by the University of Massachusetts-Dartmouth, USA, by Chen et al. (2003) and is still actively being developed. FVCOM is a three dimensional (3D) ocean model using the finite volume method to discretise the governing equations in integral form and solve them numerically using the finite difference method over the computational grid. FVCOM uses an unstructured irregular grid in the horizontal plane, composed of triangular elements which can vary in shape and size.

Below is a summary of the datasets used to force the Scottish Shelf Waters Reanalysis. More information is available at www.tinyurl.com/SSW-Reanalysis

Open boundary forcing along the Atlantic boundary:
The Atlantic boundary was forced by the Met-Office European North West Shelf ocean physics reanalysis for temperature, salinity, residual (non-tidal) current speed, and residual sea surface height (SSH) (O’Dea et al., 2012, 2017, previously available from Copernicus Marine Service, https://marine.copernicus.eu, NORTHWESTSHELF_REANALYSIS_PHY_004_009) were combined with hourly tidal current speeds and SSH from TPXO9-atlas harmonic tides (Egbert and Erofeeva, 2002).

Open boundary forcing along the Baltic boundary:
The Baltic boundary was forced by the Swedish Meteorological and Hydrological Institute (SMHI) hourly Baltic Sea Physics Reanalysis data for SSH and residual current speeds. These were supplemented with tidal currents from TPXO9-atlas tidal harmonics (Egbert and Erofeeva, 2002). The Baltic Sea Physics Reanalysis data were used for daily temperature, salinity, residual current speed, and SSH. These reanalysis data can be found on the Copernicus Marine Service (https://marine.copernicus.eu, BALTICSEA_REANALYSIS_PHY_003_011).

Atmospheric forcing:
ERA5 atmospheric data (Hersbach, 2020) were used for surface forcing of mean sea level pressure, precipitation, evaporation, surface air temperature, thermal/solar radiations and wind velocity.

Fresh water forcing:
Climatological daily river volume fluxes from the Hydrological Predictions for the Environment over Europe (E-HYPE) dataset from the SMHI (Arheimer et al., 2020) were used for fresh water forcing of the SSW-RS domain. This dataset was combined with the Grid-to-Grid (G2G) model from the Centre for Ecology and Hydrology to include river fluxes outside of Scotland and Northern Ireland. The combined dataset of Scottish-Northern Irish rivers with Northwest European Shelf rivers contains daily volume flux and temperature for 912 rivers in the SSW-RS domain.

Data Assimilated:
Daily sea surface temperatures were assimilated from the Ocean Data Analysis System for Marine Environment and Security for the European Area (ODYSSEA) satellite dataset (Autret et al., 2019), available on the Copernicus Marine Service (https://marine.copernicus.eu, SST_ATL_SST_L4_REP_OBSERVATIONS_010_026).

Bathymetry:
The Atlantic Margin Model 1.5 km gridded bathymetry was interpolated to the unstructured SSM grid. These bathymetry data originated from EMODnet (https://emodnet.eu), adjusted from lowest astronomical tide (LAT) to mean sea level (MSL) vertical reference datum (Graham et al., 2018).

A paper detailing the development of the SSW-RS and the data used to force it is currently being produced (Barton et al., In prep.).

References:

Arheimer, B., Pimentel, R., Isberg, K., Crochemore, L., Andersson, J. C. M., Hasan, A., & Pineda, L. (2020). Global catchment modelling using World-Wide HYPE (WWH), open data, and stepwise parameter estimation. Hydrology and Earth System Sciences, 24(2), 535–559. https://doi.org/10.5194/hess-24-535-2020

Autret, E., Piollé, J. F., Tandéo, P., Prévost, C. (2020) ODYSSEA Level 4 Sea Surface Temperature Reprocessing over the European North West Shelf / Iberai Biscay Irrish Seas Reprocessing SST-ATL-SST-L4-REP-OBSERVATIONS-010-026, Tech. Rep. 1.3, https://resources.marine.copernicus.eu/documents/PUM/CMEMS-SST-PUM-010-0...

Chen, C., Liu, H., & Beardsley, R. C. (2003). An Unstructured Grid, Finite-Volume, Three-Dimensional, Primitive Equations Ocean Model: Application to Coastal Ocean and Estuaries. Journal of Atmospheric and Oceanic Technology, 20(1), 159–186. https://doi.org/10.1175/1520-0426(2003)020<0159:AUGFVT>2.0.CO;2

Egbert, G. D., & Erofeeva, S. Y. (2002). Efficient inverse modeling of barotropic ocean tides. Journal of Atmospheric and Oceanic Technology, 19(2), 183–204. https://doi.org/10.1175/1520-0426(2002)019<0183:EIMOBO>2.0.CO;2

Graham, J. A., O’Dea, E., Holt, J., Polton, J., Hewitt, H. T., Furner, R., Guihou, K., Brereton, A., Arnold, A., Wakelin, S., Castillo Sanchez, J. M., & Mayorga Adame, C. G. (2018). AMM15: a new high-resolution NEMO configuration for operational simulation of the European north-west shelf. Geoscientific Model Development, 11(2), 681–696. https://doi.org/10.5194/gmd-11-681-2018