The Jason series of satellites have been using radar altimeters to make measurements of sea surface height for 15 years. Built through a partnership between NASA and France’s Centre National d'Études Spatiales, Jason-1 flew from 2001 to 2013. The Ocean Surface Topography Mission/Jason-2 was launched into orbit in 2008, and it continues to be one of the key observers of the current El Niño event. Jason-3 is scheduled for launch in January 2016 from Vandenberg Air Force Base.
Jet streams are rivers of high-speed air in the atmosphere. They form along the boundaries of global air masses where there is a significant difference in atmospheric temperature. Fluctuations in northern hemisphere jet streams over the past few years have led to polar vortex events, bringing record cold and warm winter weather to different parts of the world.
Jerusalem is one of the oldest continuously settled cities in the world and a focal point of the Jewish, Muslim, and Christian faiths.
Jakarta is one of the fastest growing cities in the world and the capital of Indonesia. The population of this urban area has roughly quadrupled since 1975.
And, of course, at the top of this page we have a jade-colored coral reef juxtaposed against the jumble of the sea. On July 17, 2015, the Operational Land Imager on Landsat 8 captured this natural-color image of Trunk Reef, near Townsville, Australia.
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NASA Earth Observatory image by Joshua Stevens, using Landsat data from the U.S. Geological Survey. Caption by Mike Carlowicz and Adam Voiland.