Details of a new and unique satellite dataset designed to advance the study of wave climate variability have been published by the Climate Change Initiative’s (CCI) Sea State project team, in the journal, Earth System Science Data.

The paper describes the production of the first version of a long-term, continuous, Sea State climate dataset and covers the reprocessing, merging and calibration of historical and current observations from space.

Long term observations describing sea state have been generated from shipping, in-situ buoy networks and satellite altimeters. But existing records are sparse and not always consistent.

Aware of the increasing need for accurate, robust and consistent long-term sea state data required by the climate science community the Global Climate Observing System(GCOS) has listed "Sea State" as an Essential Climate Variable (ECV).

Due to their almost global coverage, satellites provide the data necessary to understand the large-scale variability of sea states and their interactions with the other components of the Earth’s climate.

The new space-derived climate data record, covers the period 1991-2018 and includes observations from 10 altimeter missions – from ERS-1 to the more contemporary Cryosat-2 and Jason-3 missions. Already it has proven useful to investigate sea state variability at global and regional scales, in terms of wave climatology and spectral variability.

Sea state – the statistical properties of wind-waves – is an important component of the climate system coupling between the ocean and the atmosphere, the coasts and the sea ice. Significant changes in future sea state conditions are anticipated, as Earth’s climate responds to rising greenhouse concentrations.

The Sea State CCI dataset v1 is freely available. The paper, led by Guillaume Dodet of Laboratoire d’Océanographie Physique et Spatiale (IFREMER), considers future developments of the data within the Sea State CCI project.

The paper presents:

  • the implementation of the first release of the Sea State CCI dataset
  • the implementation and benefits of a high-level denoising method, its validation against in-situ measurements and numerical model outputs,
  • future developments considered within the Sea State CCI project

Access Sea State CCI data

The Sea State CCI dataset v1 is freely available on the ESA CCI Open Data Portal at

Three products are available: