Use up-to-date altimeter standards for L3 1Hz & 5Hz production and H2B upstream change
DUACS-NG system version : 3.0.0
Implementation date : July 2024
The version of the altimeter standards and geophysical corrections applied on altimeter measurement continuously evolve. An update of the altimeter standards is taken into account in the NRT production with the DUACS-NG 3.0.0 version. The main changes are described below:
- the use of the new FES_2022 ocean tide correction. As reported by Carrere et al., (2023), the use of the FES_2022 model instead of FES_2014 model leads to a strong reduction in the SLA variance in the coastal band (< 100km). This reduction reaches -20 cm² (Jason-3) to -50 cm² (AltiKA & Cryosat-2) at few kilometers near the coast.
The use of a new Mean Sea Surface corresponding to the Hybrid-2023 version. It combines the MSS SIO_2023, CNES_CLS_2022 and DTU2021, as presented in Laloue et al., (2024). The new MSS shows lower errors than the previous MSS solution. It contributes to improve the quality of the SLA in the near coast area (error reduced by ~23% in the 0-200km coastal band compared to the CNES_CLS_2022) and in the Arctic Ocean. The change of the MSS induces regional biases about ±5 cm in seasonal ice-covered areas, especially in the Arctic, as illustrated in the map below (Figure). This bias will be introduced in the DUACS products gradually as the summer ice melts in the region.
