A new ocean tide loading model in the Canary Islands region

Abstract

A new high-resolution (1/12◦ ×l/12◦) regional ocean tide model for Canary Islands region (Spain), by assimilating TOPEX/Poseidon altimetry data and tide gauge measurements into a hydrodynamic model, is presented. This regional ocean tide model is also refined along all the coastlines in the Canary region, using automatic grid discretization and bilinear interpolation. The new ocean model obtained reveals differences in some areas when we compare it with global models. The results confirm that data assimilation for high resolution models improves the ocean tide estimation in complex areas as the Canarian Archipelago. Gravity tide measurements, which are available in two islands of the Canarian Archipelago, have been used to test the ocean tide model. In addition, a comparison of nine global ocean tide models, supplemented with the regional model, is done for the M2 and O1 tidal constituents. The tidal gravity residues reveal that, for the M2 wave, there exists a dependence of the global ocean tide model considered. In general, the agreement of the nine ocean models is rather similar, although TPXO.2 and SCHW displays the most discrepant results. Among the ocean tide models, which are in close agreement at both places for M2 and O1 tidal waves, no one of them give better results than other.