Stalled Weather Systems
More Frequent in Decades of Warmer Atlantic
"These warmer and more saline waters then invade the subpolar ocean and cause a series of impacts," said Peter Rhines
Slow-moving winter weather systems that can lead to massive snowfalls are more frequent during the decades when the North Atlantic Ocean is warmer than usual, a new NASA study finds. The study demonstrates that the impacts of such systems, which are often fueled by an atmospheric phenomenon known as atmospheric blocking, go far beyond the atmosphere and can trigger changes in ocean circulation.
Blocking events occur when one of the jet streams —fast-flowing air currents traveling around the Earth in the upper part of the troposphere—pinches off large masses of air from the normal wind flow for an extended period. These kinks in the jet stream typically last at least five days but can persist for weeks. They can cause weather patterns to stall over one area and fuel floods, droughts, and other extreme weather events.