Sentinel-3’s Synthetic Aperture Radar Altimeter (SRAL) provides data on sea-level rise, supporting the long-term datasets of missions such as Copernicus Sentinel-6 and Jason. The introduction of high-precision altimetry has enabled scientists to establish the rate of sea-level rise, which stands at a global average of 3.64 mm per year since 1999, and is accelerating.

The mission contributes valuable altimetry data to long-term datasets on sea-ice thickness, together with other missions, helping scientists to understand and predict when this crucial climate indicator reaches record lows. As part of ESA’s Climate Change Initiative Sea Ice Project, Sentinel-3 data on sea-ice in the Arctic were analysed together with data from ESA’s CryoSat and SMOS missions.

Along with the other Sentinel missions, Sentinel-3 provides data for Copernicus, the Earth observation component of the European Union’s Space Programme. It provides rapid data and mapping for emergency activations, for example for flooding and wildfires. There have been more than 77 activations of the Copernicus Emergency Management Service (CEMS) since the beginning of 2026: more than half of the activations have been for wildfires (data as of 2 September).

According to ESA’s Co-Mission Scientist for Sentinel-3 Next Generation, Simon Proud, Sentinel-3 is excellent at monitoring extreme events, with the European heatwaves this summer providing several examples. He explained, “While Sentinel-2 provides high-resolution data on wildfires, it only covers a narrow area each day. The wide-swath thermal and optical observations from Sentinel-3, via instruments such as SLSTR, enable global, daily, detection of wildfires and other extreme events. In terms of storms and flooding, Sentinel-3 measures sea-surface height, temperature, and wind/wave dynamics over open waters, which helps track marine storm surges and typhoons.”

Although the two Sentinel-3 satellites currently in orbit were launched in 2016 and 2018, the processing and use of Sentinel-3 data continues to evolve – for example the new strategy for capturing and downloading data over central Europe. Jerome explained that the ESA team are constantly looking for ways to improve processes, “We have seen a reduction in the time it takes for the satellite to capture the data then transmit data to a ground station, enabling data to reach end users much faster. We are also helping users to work with data in new ways – well beyond what was originally planned for the mission.”

Examples of evolving ways of analysing the data from Sentinel-3 include its data on sea-ice thickness and hydrology over land. Nic added, “We are always looking for ways to improve the way we use the satellite’s optical and altimetry data. Since Sentinel-3A was launched in 2016, we have found ways to develop the algorithms and process data in more efficient ways to give greater insights into our climate and environment.”