Ocean tides in the Antarctic Peninsula: regional model adjustment

The Antarctic Peninsula region remains one of the most challenging areas for ocean tide modeling because of the limitations of satellite altimetry caused by sea ice, the scarcity of tide gauge stations, and the lack of reliable bathymetric information beneath extensive ice shelves. Nevertheless, accurate ocean tide models are important for both Earth science research and practical applications. This study presents a regional validation and assessment of five recent ocean tide models around the Antarctic Peninsula using tidal parameters derived from in situ observations at 64 tide gauge stations. The analysis focuses on the four principal tidal constituents: M2, S2, K1, and O1. The comparison of the FES2022, FES2014b, GOT5.6, EOT20, and CATS2008_v2023 models with the in situ observations reveals generally homogeneous performance among the models. Root mean square values of the differences between the modeled and observed tidal parameters, averaged over all available tide gauge stations, range from 2 to 5 cm for all analyzed models and constituents. These values are lower than those reported for earlier models in previous studies, demonstrating an overall improvement in the performance of ocean tide models in this region. The root sum square of the root mean square values for the four principal constituents ranges from 7 to 9 cm. Our regional model improvement, based on interpolating amplitude factors and phase shifts using two-dimensional splines with adjustable tension, reduces the root mean square values to 1-4 cm. The best agreement with the observations is achieved by the regional improvement of the EOT20 model. Our results highlight the need for additional tidal observations in the Antarctic Peninsula.