How Sentinel-3 tracks local weather change

Contribution to local weather information

For the reason that first Sentinel-3 satellite tv for pc was launched a decade in the past, the mission’s knowledge on oceans, land and environment have been utilized in quite a lot of scientific contexts, from revealed tutorial analysis and evaluation, to the studies that underpin world local weather insurance policies. The mission captures change within the oceans, on land, ice and atmospheric situations, monitoring environmental change in marine ecosystems, land floor dynamics and atmospheric processes.

What allows the mission to play such an integral position in our information of local weather change is its distinctive mixture of sensors on board every satellite tv for pc, in keeping with ESA’s Sentinel-3 Challenge Supervisor, Nic Mardle. “Utilizing these major devices together brings extremely invaluable outcomes. Added to that, the wide-angle of the devices allows the mission to seize knowledge shortly throughout complete areas. It’s the solely present mission throughout the Copernicus household with such a various capability.”

From monitoring ocean and ice floor traits, to land warmth and altering land use comparable to forest cowl, in addition to monitoring greenhouse gases within the environment, Sentinel-3 knowledge give a broad overview of virtually each system on Earth. The mission has contributed to datasets that inform the Intergovernmental Panel on Local weather Change (IPCC) reports, which have turn out to be synonymous with the newest scientific information on Earth’s local weather.

ESA’s Director of Earth Commentary Programmes, Simonetta Cheli, underlined the mission’s essential position in supporting the efforts of the IPCC, noting “The Sentinel-3 satellites ship exceptionally correct knowledge on virtually all features of our surroundings, making the mission extremely related within the growth and implementation of devoted EU insurance policies associated to local weather change. The addition of a 3rd satellite tv for pc ensures the mission’s continuity, enabling us to spend money on our resilience to local weather change and proceed monitoring key indicators of local weather change.”

Knowledge from the mission additionally present inputs to the 55 local weather indicators outlined and agreed by the Global Climate Observing System (GCOS), generally known as Essential Climate Variables (ECVs). Jerome Bouffard, Sentinel-3 Mission Supervisor at ESA, stated, “Sentinel-3 knowledge are broadly utilized in what we name ECVs. As a result of the mission captures such a variety of geophysical knowledge, it contributes to datasets upon which a number of local weather science relies.”

Atmospheric chemistry

Sentinel-3 satellites present world protection every day. Its multi-band radiometers are capable of observe methane concentrations in high-resolution, supporting knowledge from different Copernicus missions, comparable to Sentinel-5P and Sentinel-2.

In 2023, the mission contributed knowledge to research on among the methane ‘super-emitters’. Researchers discovered that Sentinel-3 can detect methane leaks of at the least 10 tonnes per hour, relying on location and climate situations, each single day, inserting the mission in a novel place to establish and monitor such leaks.

Sentinel-3’s measurements additionally assist datasets that monitor carbon emissions, air pollution and mud particles. The mission’s wide-angle sensors, capable of seize knowledge over an space of as much as 1400 km throughout, are suited to monitoring phenomena on regional or nationwide scales, comparable to industrial emissions that unfold throughout borders, in addition to smoke from wildfires, volcanic eruptions and mud storms.

Land and vegetation

Sentinel-3 has persistently supplied temperature measurements that present heatwaves in addition to wildfires. This picture of land floor temperatures throughout Europe present how sizzling the summer season 2026 season has been within the northern hemisphere.

Sentinel-3 additionally offers knowledge over the world’s forests, together with vegetation indexes and mapping forest cowl and land-use adjustments. The mission can measure droughts, monitor wildfires and map burn scars.

Water and ice cycles

Along with different Sentinel missions, Sentinel-3 has revolutionised our understanding of the water cycle by offering observations on a worldwide scale for water ranges in seas, rivers and lakes, in addition to sea surface temperatures, ocean colour and the thickness of land and sea ice.

Jerome explains, “Sentinel-3 has been able to produce datasets on the height and thickness of sea ice, in a way that was not planned at the beginning of the mission. The mission is also producing exceptional altimetry data – better than foreseen – on Earth’s water systems, such as the levels of lakes and rivers, as well optical data on sea ice extent. The mission has a real complementarity between optical and altimetry measurements.”

Sentinel-3 reliably measures sea surface temperature, thanks to its very accurate thermal sensor, which is critical to understanding our changing oceans. The mission’s Sea and Land Surface Temperature Radiometer (SLSTR) is designed with excellent calibration, making it a reference instrument for measurements of sea surface temperature. It also supports research into a wide range of ocean characteristics, from biodiversity to acidification.

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 invaluable altimetry knowledge to long-term datasets on sea-ice thickness, along with different missions, serving to scientists to grasp and predict when this important local weather indicator reaches report lows. As a part of ESA’s Climate Change Initiative Sea Ice Project, Sentinel-3 knowledge on sea-ice within the Arctic had been analysed along with knowledge from ESA’s CryoSat and SMOS missions.

Supporting Copernicus companies

Together with the opposite Sentinel missions, Sentinel-3 offers knowledge for Copernicus, the Earth remark part of the European Union’s Space Programme. It offers fast knowledge and mapping for emergency activations, for instance for flooding and wildfires. There have been greater than 77 activations of the Copernicus Emergency Management Service (CEMS) because the starting of 2026: greater than half of the activations have been for wildfires (knowledge as of two September).

Based on ESA’s Co-Mission Scientist for Sentinel-3 Subsequent Technology, Simon Proud, Sentinel-3 is great at monitoring excessive occasions, with the European heatwaves this summer season offering a number of examples. He defined, “Whereas Sentinel-2 offers high-resolution knowledge on wildfires, it solely covers a slim space every day. The wide-swath thermal and optical observations from Sentinel-3, through devices comparable to SLSTR, allow world, each day, detection of wildfires and different excessive occasions. By way of storms and flooding, Sentinel-3 measures sea-surface top, temperature, and wind/wave dynamics over open waters, which helps observe marine storm surges and typhoons.”

Evolving makes use of

Though the 2 Sentinel-3 satellites at present in orbit had been launched in 2016 and 2018, the processing and use of Sentinel-3 knowledge continues to evolve – for instance 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.”

Launch of Sentinel-3C

Currently Sentinel-3A and Sentinel-3B are in orbit but they will soon be joined by a third satellite. Sentinel-3C, together with ESA’s FLEX mission, is due to launch on board a Vega-C launcher from Europe’s Spaceport in French Guiana on 15 September (03.21 CEST, 22:21 local time on 14 September). Sentinel-3 is operated jointly by Eumetsat and ESA on behalf of the European Commission.

“With the launch of Sentinel-3C, we will secure stability for the mission,” noted Nic, adding, “The design of the Sentinel-3C satellite has built on the results of its two sister satellites, Sentinels -3A and -3B, and it ensures continuity of the mission, which provides essential services as well as critical knowledge about our climate and the effects on our changing world.”

At 35 m tall, Europe’s Vega-C rocket can launch 2300 kg into space, making it suitable for the launch of small scientific and Earth observation spacecraft. ESA’s FLEX mission and Sentinel-3C are fitted inside Vega-C’s fairing with a secondary payload adapter called Vespa. They are then deployed into orbit in turn with Sentinel-3C deploying first. The Vega-C programme is led by ESA, working with Avio as prime contractor and design authority. It ensures that Europe has versatile and independent access to space.

Check this page for updates on how to watch the launch of Sentinel-3C and FLEX.