The Copernicus Sentinel-6/Jason-CS mission is collecting precise data on the ocean surface and atmosphere during the current El Niño, in an effort to improve hurricane forecasts, particularly predictions of how quickly storms will intensify before reaching the coasts. The mission consists of the Sentinel-6B and Sentinel-6 Michael Freilich satellites, which operate together in orbits separated by about 30 seconds.
NASA and its European partners launched Sentinel-6B last November, and the satellite began providing low-latency data that can be used in weather forecasts on July 15. These data will need time before being integrated into the research models used by meteorological and climate experts, but their incorporation could improve the models used to track hurricanes and make disaster-response decisions.
How Do the Satellites Measure the Risk of Rapid Hurricane Intensification?
Each satellite uses a radar altimeter that sends thousands of pulses per second toward the sea surface and then measures their reflection from wave crests and troughs. Ocean-surface-height measurements provide an indicator of its heat content because warm water expands and raises sea level. This relationship helps scientists estimate the amount of energy available to a storm and how likely it is to intensify rapidly.
The satellites also measure wave height and marine wind speed, and carry a second instrument called GNSS-RO to measure atmospheric properties, including humidity, pressure, and temperature. Deirdre Byrne, a NOAA oceanographer and altimetry expert, believes that ocean-height data will be the most important data to incorporate into the Satellite Ocean Heat Content Suite algorithm, which has been operating since 2012.
Why Does This News Matter?
Hurricanes can intensify rapidly during the 48 hours before making landfall, leaving local authorities limited time to make decisions such as evacuating residents or mobilizing resources. Data from Sentinel-6 satellites feed into hurricane-tracking algorithms used by federal and state agencies, and their results could affect the deployment of sandbags, activation of the National Guard, and involvement of the Federal Emergency Management Agency when needed.
El Niño redistributes ocean heat and changes rainfall and storm patterns; it can also shift hurricane activity from the Atlantic to the Pacific. According to NASA, the phenomenon began late in the middle of the year, and scientists expect it to reach a strength similar to that recorded by satellites during the notable El Niño events of 1997 and 2015.
Continuity of Measurement Before Speed of Results
The mission’s importance is not limited to new data; it extends a continuous record of sea-level measurements that began with the TOPEX/Poseidon mission in 1992. Sentinel-6B is scheduled to take over later this year as the reference satellite for global sea-level measurements, succeeding Sentinel-6 Michael Freilich.
The mission was jointly developed by ESA, EUMETSAT, NASA, and NOAA, with support from the European Commission and technical contributions from the French space agency CNES. Its practical benefit remains dependent on integrating the measurements into operational models; the source explains that this process has not yet been completed and does not provide a quantitative estimate of the expected improvement in forecast accuracy.