Sea level rose two feet this summer on the US east coast

Brian Handwerk in National Geographic: Sea levels rose as much as 2 feet (60 centimeters) higher than predicted this summer along the U.S. East Coast, surprising scientists who forecast such periodic fluctuations. The immediate cause of the unexpected rise has now been solved, U.S. officials say in a new report (hint: it wasn't global warming). But the underlying reason remains a mystery.

Usually, predicting seasonal tides and sea levels is a pretty cut-and-dried process, governed by the known movements and gravitational influences of astronomical bodies like the moon, said Rich Edwing, deputy director for the Center for Operational Oceanographic Products and Services at the U.S. National Oceanic and Atmospheric Administration (NOAA).

But NOAA's phones began ringing this summer when East Coast residents reported higher than predicted water levels, much like those associated with short-term weather events like tropical storms. But these high seas persisted for weeks, throughout June and July.

The startling rise caused only minor coastal flooding—but major head scratching among scientists. Now a new report has identified the two major factors behind the high sea levels—a weakened Gulf Stream and steady winds from the northeastern Atlantic….

Ocean waves shot by Sean O'Flaherty aka Seano1, Wikimedia Commons, under the Creative Commons Attribution ShareAlike 2.5 License.