We have observed the continuing loss of Arctic sea ice through satellite images for decades, and based on computer modeling and observation, it is expected to continue through the 21 st century. It won’t be too many years into the future before the Arctic will be ice-free during the summer.
According to a new study by Ivana Cvijanovic and colleagues from Lawrence Livermore National Laboratory and the University of California, Berkeley, as temperatures continue to rise, the Arctic Ocean will be ice-free within a decade or two, resulting in more of the sun’s heat being stored in the Arctic’s waters.
The hotter Arctic Ocean waters will give birth to the development of an atmospheric ridging system in the North Pacific, causing atmospheric circulation changes and cloud formations in the tropical Pacific Ocean as they move north. This feature played a significant role in the 2012-2016 California drought.
“On average, when considering the 20-year mean, we find a 10-15 percent decrease in California’s rainfall. However, some individual years could become much drier, and others wetter,” Cvijanovic said, adding that “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” on people in California and around the world.
California precipitation records show decline
Californian has seen a decrease in annual precipitation over the past few decades, with the latest severe drought being the worst on record. When the reduced amounts of rainfall are added to rising temperatures that cause increased evaporation, it suggests the recent California droughts have a human-made component.
“Our study identifies one more pathway by which human activities could affect the occurrence of future droughts over California — through human-induced Arctic sea ice decline,” Cvijanovic said.
Other co-authors on the study include Benjamin Santer (LLNL), Celine Bonfils (LLNL), Donald Lucas (LLNL), John Chiang (University of California, Berkeley) and Susan Zimmerman (LLNL). The research is funded by Department of Energy (DOE), and the research appears in the Dec. 5 edition of Nature Communications.
