Editing Jason-1 (section)

=== Ocean variability ===
[[Image:Sealevel chart.jpg|upright=1.3|right|thumb|290px|Although the 1993–2005 [[TOPEX|Topex/Poseidon]] satellite (on the left) measured an average annual Global Mean Sea Level rise of 3.1 mm/year, Jason-1 is measuring only 2.3 mm/year GMSL rise, and the [[Envisat]] satellite (2002–2012) is measuring just 0.5 mm/year GMSL rise. In this graph, the vertical scale represents globally averaged mean sea level. Seasonal variations in sea level have been removed to show the underlying trend. (Image credit: University of Colorado)]]

The missions revealed the surprising variability of the ocean, how much it changes from season to season, year to year, decade to decade and on even longer time scales. They ended the traditional notion of a quasi-steady, large-scale pattern of global ocean circulation by proving that the ocean is changing rapidly on all scales, from huge features such as El Niño and La Niña, which can cover the entire equatorial Pacific, to tiny eddies swirling off the large Gulf Stream in the Atlantic.