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NCEO scientists welcome successful launch of Sentinel-3A

NCEO scientists welcomed today’s successful launch of the first Sentinel-3 satellite (Sentinel-3a) from Plesetsk Cosmodrome, in Russia.

Scientists will use the satellite’s radiometer sensor, which measures Earth’s radiant energy, for a range of climate research, particularly to derive Sea-Surface Temperatures (SSTs).

These new data will be carefully combined with other satellite datasets of SST to measure changes to the Earth’s climate across decades. They will provide a continuity of quality SST data collected by the Along Track Scanning Radiometer (ATSR), which over the last 20 years has much improved spatial and temporal coverage.

Simulation of the interplay of ocean and atmosphere is crucial to being able to predict future tendencies of the weather and climate, and SST that will be used by climate modellers to test their models.

Professor Chris Merchant of NCEO and the University of Reading said, “We are very much looking forward to obtaining data from the first Sentinel 3 mission. Because of SLSTR’s design and calibration, the sea surface temperature measurements we will derive from its images should be very trustworthy. This helps us track the behaviour of climate.”

Sea Surface Temperature changes based on data from the world-leading UK Along Track Scanning Radiometers (ATSR). Dashed lines are estimates from in situ data sources.  Solid lines are satellite data. The globes show during and after a big El Niño Southern Oscillation with red = warm; blue = cold.  In an El Niño year (top), global temperatures are much higher on average than in a La Niña year (bottom) with temperature patterns which drive global weather.


SLSTR has been developed through a collaboration between Selex ES (Florence), Jena Optronik, and STFC-RAL Space for the ESA/EU Copernicus Sentinel 3 Satellite led by Thales Alenia Space in Cannes.

Dr Chris Mutlow, Director of RAL Space, said, “SLSTR is a second generation SST sensor which will carry on the climate observations started by the ATSR programme. The successful completion of the SLSTR instrument calibration has required a great deal of hard work from our team at RAL over the last few months, and represents a major milestone for ESA/EU and all the contractors around Europe who have spent years building the instrument.”

“Like the rest of the science and operational communities we are now keen to have SLSTR in space, operational and delivering high-quality SST data to users,” he added.

The calibration was performed in a purpose-built rig designed to allow the SLSTR instrument to view the different calibration sources under carefully controlled conditions that replicates the in-flight environment.  The measurements ensure that the calibration of the data generated by SLSTR can be traced to reference standards as required for accurate climate monitoring.

These activities require major computing power, and the UK has created a facility for collecting and processing large volumes of SLSTR and other data, at Harwell.

Professor John Remedios, Director of NCEO, said, “The Along Track Scanning Radiometers (ATSRs) and the new Sea and Land Surface Temperature Radiometers (SLSTRs) show how the UK is delivering significant evidence regarding the magnitude of change in ocean temperatures. The high quality data from these instruments also serves many operational applications which add value to this core mission which involves many leading UK scientists.”

NCEO experts will be using the SLSTR instrument to provide essential new information on the land including fires and land surface temperature.

It has two specifically designed detector systems which are sensitive enough to detect fires burning across as little as 100 m², which is only 1/10000th of the area covered by a single SLSTR pixel.

Professor Martin Wooster of NCEO and King’s College London hopes to use this important data to map the radiative heat emitted by fires burning worldwide, and relate this to emissions of carbon dioxide and other gases and aerosols. In an El Niño year, the impact of fires on Earth’s land and atmosphere can be especially severe, as was the case in 1997-1998.

Image credit: Copernicus data (2016).