Study links California drought, polar vortex to climate change

Kevin Opsahl in Idaho State Journal:  A Utah State University study has found a link between climate change and two of the biggest extreme weather events that have played out in the first half of the year — the California drought and the polar vortex.

The new study blames an unusual “dipole,” a combination of a strong Western high pressure ridge and a deep Great Lakes low pressure trough. That dipole is linked to a recently found precursor to El Nino, the weather-changing phenomenon. And that precursor itself seems amplified by a buildup of heat-trapping greenhouse gases, the study says.

 The author of the study, Simon Wang, saw the precursors and weather event coming months before federal weather officials issued an official El Nino watch last month. Wang is assistant director of the Utah Climate Center — a state research facility based at USU — and worked with other professors on the study, which is set to be published in Geophysical Research Letters.

“I believe we have uncovered another important piece to link to extreme events in North America,” said Wang in an interview on Wednesday. “The first thing (people should know) is to prepare better next time a similar event hits because this 'dipole' is increasingly likely to happen again with greater intensity. ... This extreme event is not really random and is potentially traceable/predictable, and the pathway from which human-induced warming affects individual climate extreme events (is) complex but identifiable.”

The study’s findings can better help water managers and energy suppliers plan for the future, Wang said. Below-average rainfall has put the entire Golden State in drought, ranging from moderate to exceptional for the first time in 15 years, according to the Los Angeles Times. The polar vortex — which occurred at the beginning of the year — was a powerful high pressure system originating in the Eastern Pacific stretching to the North Pole, shoving the vortex farther south than is typical, allowing it to settle in Canada and the U.S....

Chicago during the 2014 winter, shot by akasped, Wikimedia Commons via Flickr, under the Creative Commons Attribution 2.0 Generic license