Jet Stream Visualization (IMAGE) University of Arizona Caption In this visualization, which uses weather and climate observations from NASA's MERRA dataset, the Northern Hemisphere's polar jet stream is seen as a meandering, fast-moving belt of westerly winds that traverses the lower layers of the atmosphere. Credit NASA Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.