Loss of ice cover in the Arctic could spur more droughts in California, according to a new study by federal researchers. The study, published today in Nature Communications, finds that sea-ice loss in the Arctic could trigger atmospheric effects that drive precipitation away from California. The research was led by atmospheric scientists at the Lawrence Livermore National Laboratory. It's the same kind of effect that contributed to state's historic dry period that ended last year. The five-year drought was exacerbated by an atmospheric pressure system in the North Pacific Ocean that researchers dubbed the "ridiculously resilient ridge," which pushed storms farther north and deprived the Southwest of precipitation. "
ea-ice loss of the magnitude expected in the next decades could substantially impact California's precipitation, thus highlighting another mechanism by which human-caused climate change could exacerbate future California droughts," the study says.
The study stops short of attributing California's latest drought to changes in Arctic sea ice, partly because there are other phenomena that play a role, like warm sea surface temperatures and changes to the Pacific Decadal Oscillation, an atmospheric climate pattern that typically shifts every 20 to 30 years.
The recent drought is also outside the study's scope because the researchers focused on potentially larger losses in sea ice than have occurred to date. The authors predict that over the next 20 years, California could see a 10 to 15 percent decrease in rainfall on average.
Read More: Scientific American