CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023

CATS2008_v2023 is an update of the original CATS2008 tide model (Howard et al., 2019 [https://doi.org/10.15784/601235]; Padman et al., 2002 [https://doi.org/10.3189/172756402781817752]). It introduces a new model file format, increased resolution, more accurate coastlines, and a simple scaling for ice shelf flexure near grounding lines. The changes included in the new CATS2008_v2023 model are: (1) The CATS2008 model has been interpolated to a finer grid (2 km for CATS2008_v2023 vs 4 km for CATS2008) to provide a better representation of coastlines and ice shelf grounding lines. (2) Coastlines have been adjusted to match BedMachine Antarctica v3 (Morlighem et al., 2020 [https://doi.org/10.1038/s41561-019-0510-8]; Morlighem, 2022 [https://doi.org/10.5067/FPSU0V1MWUB6]). Areas that were previously grounded and had no tidal constituent data in CATS2008 have been filled using MATLAB's ‘regionfill’ function, applied to the real and imaginary components of tidal constituents individually. An ocean mask matching BedMachine Antarctica v3 is provided in the model file to mask out grounded areas. (3) Water depth (water column thickness under ice shelves) has been adjusted to match BedMachine Antarctica v3. (4) An ice shelf flexure model has been included for estimating tidal deflections in grounding zones. Flexure is approximated by a forward 1D linear elastic model applied to BedMachine Antarctica v3 ice geometry, with elastic modulus E=4.8 GPa and Poisson's ratio nu=0.4. The ice flexure can be included as an option when using TMD3.0 (Greene et al., 2024 [https://doi.org/10.21105/joss.06018]) and pyTMD (Sutterley, 2024 [https://doi.org/10.5281/zenodo.10501349]) software packages. (5) The model is provided as a consolidated NetCDF file that can be used with TMD3.0 and pyTMD, but not with earlier TMD versions.