Abstract's details

Homogeneous along-track sea level anomalies (Level-2+) data set for all altimetry missions

Sabine Philipps (CLS, France)


Marine Lievin (CLS, France); Isabelino Denis (CNES, France); Thierry Guinle (CNES, France); Carolina Nogueira Loddo (EUMETSAT, Germany)

Event: 2019 Ocean Surface Topography Science Team Meeting

Session: Outreach, Education and Altimetric Data Services

Presentation type: Type Poster

Contribution: not provided


Since the launch of TOPEX/Poseidon and ERS-1 in the early 90’s more than 10 other Altimetry missions were launched and operated by different agencies. The level 2 data (destinated to expert users) are distributed using different file formats (binary, netcdf) and contain different geophysical standards used to compute the sea level anomaly. Some dataset evolve rapidly and are regularly reprocessed, whereas other datasets, especially from finished missions are seldom reprocessed or not at all (and therefore do not profit from new standards).

In the frame of the SALP (Service d’Altimétrie et de Localisation Précise) project supported by CNES (Centre National d’Etudes Spatiales) and of the Sentinel-3 Marine Altimetry L2P-L3 Service (operated under an EUMETSAT contract in the frame of the Copernicus Programme funded by the European Union) level 2P data are available to users for all the altimeter missions (TOPEX/Poseidon, Jason-1/2/3, ERS-1/2, Envisat, Saral/AltiKa, Sentinel-3A/B, GFO, Cryosat-2, HY-2A) in delayed time on AVISO+ ( https://www.aviso.altimetry.fr/en/data/products/sea-surface-height-products/global/along-track-sea-level-anomalies-l2p.html ).

Hereafter the value-added sea level anomaly L2P products are presented. They are easy to use (netcdf format) homogenous along-track mono-mission products, providing as much as possible the same updated corrections and models for the altimeter missions, in order to facilitate inter-mission comparisons. The products contain the sea level anomaly as well as all the corrections used to compute it. The sea level anomaly is provided with a validity flag, enabling users to discard data with spurious measurements. Furthermore an inter-mission bias is applied in order to have consistent time series since TOPEX/Poseidon.

The sea level anomaly level 2P products can be for example used for mean sea level computation, but they are also the input data for level 3 products (Taburet et al. 2019, DUACS DT-2018: 25 years of reprocessed sea level altimeter products).

A reprocessing of the whole level-2P sea level anomaly dataset (all the missions) is foreseen for early 2020 taking into account the recommendation of new standards from the OSTST.

Level-2P data are also available to users in the following timeliness for Sentinel-3A and Sentinel-3B:

- Near-Real-Time sea level anomaly (L2P data are available on AVISO+ generally less than 4h after the sensing start time of the product)

- Short-Time-Critical sea level anomaly (L2P data are available on AVISO+ generally less than 2 days after sensing start time of the product)

- Near-Real-Time significant wave height

Poster show times:

Room Start Date End Date
The Gallery Tue, Oct 22 2019,16:15 Tue, Oct 22 2019,18:00
The Gallery Thu, Oct 24 2019,14:00 Thu, Oct 24 2019,15:45
Sabine Philipps