Know Your Earth 2.0: Ocean
Earth has one big ocean, with many features. Earth’s global ocean is permanently in motion, redistributing heat from the sun to the atmosphere. The constant exchange of heat between the ocean and atmosphere is a dance that drives our climate and allows Earth to support the varied life that, so far, has been found only here.
NASA’s Jason-1 and OSTM/Jason-2 satellite altimeters are adding to the database of precise measurements of ocean surface topography by accurately and continuously measuring the highs and lows of the ocean surface making for a decades-long record of global sea level change.
Satellite altimeter data provide information about the amount of heat stored in the top layer of the ocean and about surface currents and near-surface winds. Measurements from TOPEX/Poseidon, which operated from 1992 to 2005 led to early prediction of the great El Niño of 1997-1998, which as a result of changing wind patterns shifted warm surface water near the equator from West to East causing extreme disruptions to weather patterns around the globe. Changing El Niño and La Niña patterns in the Pacific also can have significant impacts on global sea level height. Data from Jason-1 and OSTM/Jason-2 indicated a 6 mm drop in global sea level in 2010. NASA scientists attributed this drop amongst a near 20-year trend toward sea level rise to the 2010 El Niño/La Niña cycle. These long-term trends and departures from them are best measured and monitored from space. Satellite altimeters have proven their utility and continue to add to our knowledge of ocean circulation and its effects on global weather and climate.