Sentinel-3C strengthens Europe’s continuous view of Earth

Sentinel-3C is now in orbit, supporting ocean monitoring and wildfire response while strengthening continuity of vital Earth observation data for users across Europe.

Environmental challenges threaten Europe's coastal communities, fisheries and tourism. Addressing these threats requires constant monitoring from space. The launch of Sentinel-3C - part of the Copernicus Earth observation (EO) programme - ensures continuous satellite data flow, with EUSPA supporting the uptake and use of Copernicus data and services by citizens, businesses, researchers and public authorities.

Hot summer weather makes swimming in open water pleasant and refreshing. Yet increasing temperatures can trigger something more troubling: algal blooms. These dense accumulations of algae appear as green, brown or red patches in oceans, seas or lakes. While some are harmless or even necessary for ecosystems, others can be toxic. They can kill fish, and they can also have a negative impact on tourism by making water-based activities less appealing.

Algal blooms are a growing concern in Europe, with potentially significant impacts on fisheries, aquaculture, tourism and coastal economies.

Equipped to gather vital information

To address environmental challenges such as algal blooms, Europe is deploying new monitoring capabilities.

On 14 September, Sentinel-3C launched aboard a Vega-C rocket from Europe's spaceport in Kourou, French Guiana alongside the European Space Agency's FLEX mission. As the third satellite in the Sentinel-3 series, it will eventually replace Sentinel-3A (launched in 2016) and will help ensure the continuous data flow required to monitor environmental change.

The new satellite carries a suite of instruments that observes the Earth's oceans, land, ice and atmosphere. It measures reflected light to track the colour of oceans and land with its Ocean and Land Colour Instrument (OLCI), which is important for monitoring algal blooms as well as land-based ecosystems and agriculture.

Sentinel-3C also has a Sea and Land Surface Temperature Instrument (SLSTR) on board that will help monitor issues such as temperature changes in the oceans and on land, and even volcanic activity.

Working together, the OLCI and SLSTR can help with the creation of fire maps, allowing fire prevention measures to be put in place. If a wildfire should break out, the satellite can detect its extent, and, in combination with Galileo, direct emergency responders to its location.

Open and accessible data

Sentinel-3 data are used in EUSPA's Fisheries and Aquaculture demonstrator and Insurance and Finance demonstrator. The Fisheries and Aquaculture online tool uses data, such as water quality and ocean state parameters, to support seaweed farmers in locating potential farms and managing operational aspects of their work, such as determining the best time to harvest. The Insurance and Finance tool leverages Sentinel-3 data in combination with other information, to assess climate risks on assets including heat stress, fire danger, active fire, heat wave and land surface temperature.

Data from Sentinel-3 are also used to track garbage patches in oceans. Garbage that ends up in the ocean tends to gather into large patches through currents. Sentinel-3 data that track sea currents, sea-surface topography, sea-surface temperature and ocean colour provide key information for modelling the ocean and identifying where these garbage patches are likely to accumulate. Research and even collection expeditions can then be more easily routed to these areas.

In addition, Sentinel-3 land surface temperature measurements support urban heat island analysis, wildfire detection, drought assessment, agriculture and crop monitoring. The mission also contributes to ice and cryosphere monitoring, including the observation of sea ice extent, ice surface temperature, glacier dynamics, and polar ice-sheet changes, supporting climate studies, environmental monitoring, and operational services in Arctic and Antarctic regions.

Reliable EO data will play an increasingly important role in adapting to climate change, informing climate policy and protecting our oceans. The Sentinel-3C launch will strengthen these efforts and help ensure data continuity, while EUSPA works to maximise the benefits of Copernicus for users across Europe.

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