Melting Arctic ice could lead to more severe droughts in California

Arctic sea ice loss of the magnitude expected in the next few decades could impact California’s rainfall and exacerbate future droughts, according to new research released December 5, 2017 led by Lawrence Livermore National Laboratory (LLNL) scientists.

The study said the melting ice could leave California vulnerable to a recurrence of the severe drought suffered in recent years, as a result of high pressure systems that push away rain-bearing storms, according to the LLNL press release.

The dramatic loss of Arctic sea ice cover observed over the satellite era is expected to continue throughout the 21st century. Over the next few decades, the Arctic Ocean is projected to become ice-free during the summer.

"This has the potential to make a drought very similar to the one we had in 2012 to 2016," said Ivana Cvijanovic, an atmospheric scientist at the Department of Energy’s Lawrence Livermore National Laboratory. "Studies like this one imply that it’s not only a problem for communities in Alaska and that Arctic Sea ice loss that we expect in the next couple of decades could have massive effects."

This atmospheric feature also played a central role in the 2012-2016 California drought and is known for steering precipitation-rich storms northward, into Alaska and Canada, and away from California. The team found that sea ice changes can lead to convection changes over the tropical Pacific. These convection changes can in turn drive the formation of an atmospheric ridge in the North Pacific, resulting in significant drying over California.

The complete study can be found in the Dec. 5 edition of Nature Communications.