The main application of Sentinel-3 in relation to climate is in determining mean sea level rise due to global warming. As the ocean warms in response to global warming, sea waters expand and, as a result, sea level rises. When mountain glaciers melt in response to increasing air temperature, sea level rises because more freshwater glacial run-off discharges into the oceans. Similarly, ice mass loss from the ice sheets causes sea level to rise. The increased amount of freshwater flowing into the oceans reduces salinity, decreasing density and affecting ocean circulation patterns, which in turn affects sea level spatial variability.
The global mean level of the oceans is an indicator of climate change. It incorporates the reactions from several different components of the climate system. Precise monitoring of changes in the mean level of the oceans is vitally important for understanding not just the climate, but also the socio-economic consequences of any rise in sea level.
Global mean sea level is an average, over all the oceans, of sea surface height, with respect to a reference. However, what is really sought, is the regional variation in sea level over time.
Figure 1: Regional Mean Sea Level Trends from October 1992 to April 2012 (Credit: CNES/LEGOS/CLS)
Figure 2: Global Mean Sea Level Trend from 1992 to 2012 Derived from SSH (Credit: Altimetrics LLC)
Quicktime animation - El Nino event March 2009 - February 2010. Cyclones have increased in the Pacific, whereas the 2009-2010 Atlantic hurricane season showed a decrease in events. El Nino, the ocean/climate phenomenon, is back. (Credit: MyOcean)
For further information about mean sea level rise see: ESA CCI Sea Level website.
For further information about climate change applications and services available, see: Copernicus website.