EOT20: An updated global empirical ocean tide model derived from multi-mission satellite altimetry - First validation results
Event: 2020 Ocean Surface Topography Science Team Meeting (virtual)
Session: Tides, internal tides and high-frequency processes
Presentation type: Type Forum only
DGFI-TUM works on the development of global empirical ocean tides models (EOT) derived by residual tidal analysis of multi-mission satellite altimetry for many years. The latest version in this series, EOT20, is about to be published in near future. The amplitudes and phases of 17 of the most dominant tidal constituents are provided on a 0.125 degree grid based on empirical analysis of 11 satellite altimetry missions. EOT20 benefits from the updated FES2014 tidal model, which is used as a reference to estimated residual tidal signals. Here, the initial results of EOT20 are presented for the major eight tidal constituents. The results are compared to tide gauges and several other global ocean tide models including the previous version of the global model, EOT11a. Validation of EOT20 using tide gauges shows significant improvements in the model compared to EOT11a, with the root-square sum (RSS) of the eight tidal constituents improving by ~3 cm for the entire global ocean. In coastal regions (<1 km), this improvement in RSS is ~3.5 cm. The reasons for this significant improvement are largely due to the improved FES2014 tide model, the inclusion of more altimetry time series as well as missions, the inclusion of the ALES coastal retracker and improved coastal representation. Compared to FES2014, the EOT20 model shows slightly improved results in the global ocean of ~0.3 cm with this largely being driven by EOT20 performing ~0.4 cm better in the coastal regions. The initial findings from EOT20 show encouraging results that will continue to be assessed following different techniques in the near future.