EARTH.COM - The majority of California’s water comes from the Pacific Ocean. Atmospheric rivers build over the sea, ride the jet stream east, and slam into the Sierra.
When forecasters track wet winters, they watch ocean temperatures off the coast to predict weather conditions.
However, they may need to look beyond what is proximate. A new study finds that one driver of California’s wettest storms sits half a world away – in the Atlantic Ocean.
A slowing ocean engine
The Atlantic Meridional Overturning Circulation (AMOC) carries warm water north toward the Arctic, where the water cools, sinks, and eventually flows back south.
The flow helps regulate climate across the Northern Hemisphere. Multiple lines of evidence now suggest it is slowing down.
One analysis found a roughly 15 percent decline happening since the mid-twentieth century.
Dr. Wei Liu at the University of California, Riverside (UCR) has spent years tracking that slowdown and its ripple effects.