Tidal dynamics play an important role in Kara Sea circulation, influencing currents, sea ice formation, and biogeochemical processes. However, accurate numerical simulation of these processes in regional models depends on the choice of tidal forcing at open lateral boundaries. This study evaluates the performance of three tidal models – TPXO9, FES2014, and Arc2kmTM as sources of boundary forcing for a high-resolution regional Kara Sea model based on MITgcm numerical kernel. The goal is to identify the optimal tidal forcing that best aligns with observations from coastal stations. Numerical experiments have revealed significant discrepancies in tidal energy estimates among the models. The FES2014 model has shown the closest agreement to observations, while Arc2kmTM exhibits the largest errors. However, when used as boundary forcing in the regional Kara Sea model, Arc2kmTM yields the smallest errors in simulated tidal amplitude and phase. Overall, the regional model reproduces M2 tidal amplitudes well but introduces slight phase shifts in the southwestern part of the Kara Sea. Our findings emphasize that no single tidal model can be considered universally optimal. The choice depends on regional conditions and modeling objectives. For our regional model, Arc2kmTM is recommended as a source of tidal forcing at the open boundaries of the regional model, though global models like FES2014 remain viable alternatives. This work emphasizes the need for improved validation methods and highlights the challenges posed by limited observational data in the Arctic region.
Martyanov et al. (Mon,) studied this question.