You choose, we deliver
If you are interested in this story, you might be interested in others from The Journal Gazette. Go to www.journalgazette.net/newsletter and pick the subjects you care most about. We'll deliver your customized daily news report at 3 a.m. Fort Wayne time, right to your email.

World

  • Iraqi forces, Islamic State group battle in Ramadi
     BAGHDAD – Iraqi soldiers backed by Sunni fighters launched a major operation Saturday to retake a section of the city of Ramadi seized by Islamic State group militants, an official and residents said.
  • Hundreds evacuated after London hotel explosion
     LONDON – London fire officials say a suspected gas leak touched off an explosion in the basement of a London hotel, injuring 11 people and forcing the evacuation of hundreds of guests.
  • Macedonian environmentalists blast crow hunt
    SKOPJE, Macedonia – A Macedonian environmental group is calling for the prosecution of a hunters’ association behind a midnight massacre of crows, allegedly after residents complained the birds’ droppings were spoiling their cars.
Advertisement

Study links polar vortex to shrinking sea ice level

– Remember the polar vortex, the huge mass of Arctic air that can plunge much of the U.S. into the deep freeze? You might have to get used to it.

A new study says that as the world gets warmer, parts of North America, Europe and Asia could see more frequent and stronger visits of that cold air. Researchers say that’s because of shrinking ice in the seas off Russia.

Normally, the polar vortex is penned in the Arctic. But at times it escapes and wanders south, bringing with it a bit of Arctic super chill.

That can happen for several reasons, and the new study suggests that one of them occurs when ice in northern seas shrinks, leaving more water uncovered.

Normally, sea ice keeps heat energy from escaping the ocean and entering the atmosphere. When there’s less ice, more energy gets into the atmosphere and weakens the jet stream, the high-altitude river of air that usually keeps Arctic air from wandering south, said study co-author Jin-Ho Yoon of the Pacific Northwest National Laboratory in Richland, Washington. So the cold air escapes instead.

That happened relatively infrequently in the 1990s, but since 2000 it has happened nearly every year, according to a study published Tuesday in the journal Nature Communications. A team of scientists from South Korea and United States found that many such cold outbreaks happened a few months after unusually low sea ice levels in the Barents and Kara seas, off Russia.

The study observed historical data and then conducted computer simulations. Both approaches showed the same strong link between shrinking sea ice and cold outbreaks, according to lead author Baek-Min Kim, a research scientist at the Korea Polar Research Institute. A large portion of sea ice melting is driven by man-made climate change from the burning of fossil fuels, Kim wrote in an email.

Sea ice in the Arctic usually hits its low mark in September and that’s the crucial time point in terms of this study, said Mark Serreze, director of the National Snow and Ice Data Center in Boulder, Colorado. Levels reached a record low in 2012 and are slightly up this year, but only temporarily, with minimum ice extent still about 40 percent below 1970s levels, he said.

Advertisement