Arctic ice loss could spell more drought for California, Livermore Lab study finds

Alongside the obvious perils for polar bears and other wildlife, as well as the problem of rising ocean levels, the massive ice thaw thousands of miles away is triggering changes in the atmosphere that are likely to shrink rainfall close to home, according to new research by scientists at Lawrence Livermore National Laboratory.
Their study outlines a chain of meteorological events that leads to formation of storm-blocking air masses in the North Pacific.
The masses are similar to the so-called Ridiculously Resilient Ridge that kept rain from making landfall during California’s five-year drought, forcing widespread water rationing in homes, prompting farmers to fallow fields and causing the Central Valley to sink due to heavy pumping of groundwater.
The Livermore Lab study, being published Tuesday in the journal Nature Communications, doesn’t attempt to explain the recent drought, but to help understand future weather patterns.
As such dry spells become more common, the state will average 10 to 15 percent less rain over the long haul, she estimated.
The study comes amid efforts to understand the relationship between drought and climate change.
While higher temperatures are known to increase drying through evaporation, the link between global warming and rainfall has remained in dispute.
Stanford University Earth system scientist Noah Diffenbaugh and UCLA climate researcher Daniel Swain have suggested that upticks in greenhouse gases have created conditions favorable to high-pressure systems, which generally push the east-moving Pacific storm track northward and result in dry conditions in California.
The Livermore Lab study maintains that Arctic activity is hastening the tropical influence.
“The influence from the Arctic doesn’t go first to California; it goes to the tropics.” Cvijanovic and her colleagues acknowledge that they’re far from being able to forecast long-term weather patterns for California.

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