A NASA satellite studying the Earth's oceans has produced its first global map of the salinity of the planet's seas, the space agency said. The Aquarius satellite's instruments have revealed a rich tapestry of global salinity patterns, revealing large-scale salinity distribution features clearly and with sharp contrast, the space agency said in a release Thursday. Salinity variations mapped by the satellite are a key component of Earth's climate, linked to the cycling of freshwater around the planet and influencing ocean circulation. "Aquarius is making continuous, consistent, global measurements of ocean salinity, including measurements from places we have never sampled before," Michael Freilich, director of NASA's Earth Science Division at agency headquarters in Washington, said. Although considerable calibration and validation work remains, scientists say they are impressed by the initial data's quality. "Aquarius has exposed a pattern of ocean surface salinity that is rich in variability across a wide range of scales," Aquarius science team member Arnold Gordon, professor of oceanography at Columbia University, said. "This is a great moment in the history of oceanography. The first image raises many questions that oceanographers will be challenged to explain."