The warming of Earth is primarily due to accumulation of heat-trapping greenhouse gases, and more than 90 percent of this trapped heat is absorbed by the oceans. As this heat is absorbed, ocean temperatures rise and water expands. This thermal expansion contributes to an increase in global sea level. Temperature measurements of the sea surface, taken by ships, satellites and drifting sensors, along with subsurface measurements and observations of global sea-level rise, have shown that the warming of the upper ocean caused sea level to rise due to thermal expansion in the 20th century. Using measurements from Argo profiling floats, we know this warming has continued, causing roughly one-third of the global sea-level rise observed by satellite altimeters since 2004.
The pioneering campaign drops probes from a plane into the sea to track how seawater is melting glaciers and lend insight into the future of sea level rise.
In the mid-2030s, every U.S. coast will experience rapidly increasing high-tide floods, when a lunar cycle will amplify rising sea levels caused by climate change.
Set for launch next year, the Surface Water and Ocean Topography mission will help scientists monitor Earth’s ocean, as well as the amount of fresh water in its lakes and rivers.
Sentinel-6 Michael Freilich, the latest spacecraft to monitor sea surface height, releases its first science measurements to users.
NASA scientists have studied 17 years of gravity observations of our planet to understand how the global water cycle is changing.