This dataset contains a 19.5-year-long (January 2002 to June 2021), high-resolution (20 Hz), along-track sea level dataset in most of the world coastal zones, including tropical islands. It has been developed within the sea level project of the European Space Agency (ESA) Climate Change Initiative (SL_cci).

The main objective of this dataset is to analyze the sea level trends as well as the inter-annual variability at local scale at an average of less than 2.5km from the coastline. It provides essential information in areas devoid of other sources of measurements, and it also allows filling the gaps in existing timeseries of tide gauges located nearby the stations.

This dataset of coastal sea level anomalies is based on the reprocessing of raw radar altimetry waveforms from the Jason-1, Jason-2 and Jason-3 satellite missions to derive satellite-sea surface ranges as close as possible to the coast (a process called ‘retracking’) and optimization of the geophysical corrections applied to the range measurements to produce sea level time series.

This large amount of coastal sea level estimates has been further analysed to produce the present dataset: a total of 1634 altimetry-based virtual coastal stations have been selected and sea level anomalies time series together with associated coastal sea level trends have been computed over the study time span.

The new updated version (v3.0; June 2025) of along-track coastal sea level time series and associated trends from January 2002 to June 2021 differs from the previous v2.4 product (released in November 2024) by a spatial extension. It also uses the new improved FES22 ocean tide model instead of FES14 model in the previous versions. The data editing (outlier removal) has slightly evolved, and a new variable has been added (sla_mean_10pts_filt). We strongly recommend the users to use this latest v3.0 product.

For the latest version of the documentation, see the 'Technical Coastal Sea Level' Key Documents section of the project's website (https://climate.esa.int/en/projects/sea-level/).
This dataset is v3.0 of the data and is a copy of the v3.0 data published on the SEANOE (SEA scieNtific Open data Edition) website (https://doi.org/10.17882/74354#122284).

The dataset should be cited as: Cazenave Anny, Gouzenes Yvan, Leclercq Lancelot, Birol Florence, Legér Fabien, Passaro Marcello, Calafat Francisco M, Shaw Andrew, Niño Fernando, Legeais Jean François, Oelsmann Julius, Benveniste Jérôme, Connors Sarah (2025). New network of virtual altimetry stations for measuring sea level along the world coastlines. SEANOE. https://doi.org/10.17882/74354

In addition, it would be appreciated that the following work(s) be cited too, when using this dataset in a publication :

- Cazenave Anny, Gouzenes Yvan, Birol Florence, Leger Fabien, Passaro Marcello, Calafat Francisco M., Shaw Andrew, Nino Fernando, Legeais Jean François, Oelsmann Julius, Restano Marco, Benveniste Jérôme (2022). Sea level along the world’s coastlines can be measured by a network of virtual altimetry stations. Communications Earth & Environment, 3 (1). https://doi.org/10.1038/s43247-022-00448-z

- Benveniste Jérôme, Birol Florence, Calafat Francisco, Cazenave Anny, Dieng Habib, Gouzenes Yvan, Legeais Jean François, Léger Fabien, Niño Fernando, Passaro Marcello, Schwatke Christian, Shaw Andrew (2020). Coastal sea level anomalies and associated trends from Jason satellite altimetry over 2002–2018. Scientific Data, 7 (1). https://doi.org/10.1038/s41597-020-00694-w