Combination of Tsoft and ET34-ANA-V80 software for the preprocessing and analysis of tide gauge data in French Polynesia

Abstract

Since 2008 a network of five sea-level monitoring stations was progressively installed in French Polynesia. The stations are autonomous and data, collected at a sampling rate of 1 or 2 min, are not only recorded locally, but also transferred in real time by a radio-link to the NOAA through the GOES satellite. The new ET34-ANA-V80 version of ETERNA, initially developed for Earth Tides analysis, is now able to analyze ocean tides records. Through a two-step validation scheme, we took advantage of the flexibility of this new version, operated in conjunction with the preprocessing facilities of the Tsoft software, to recover corrected data series able to model sea-level variations after elimination of the ocean tides signal. We performed the tidal analysis of the tide gauge data with the highest possible selectivity (optimal wave grouping) and a maximum of additional terms (shallow water constituents). Our goal was to provide corrected data series and modelled ocean tides signal to compute tide-free sea-level variations as well as tidal prediction models with centimeter precision. We also present in this study the characteristics of the ocean tides in French Polynesia and preliminary results concerning the non-tidal variations of the sea level concerning the tide gauge setting.