Weakening of the stratospheric polar vortex by Arctic sea-ice loss

Wednesday, 17 December 2014: 11:20 AM
Baek-Min Kim1, Seok Woo Son2, Seung-Ki Min3, Jee Hoon Jeong4, Seong-Joong Kim1, Xiangdong Zhang5, Taehyoun Shim6 and Jin-Ho Yoon7, (1)KOPRI Korea Polar Research Institute, Incheon, South Korea, (2)Seoul National University, Seoul, South Korea, (3)POSTECH, Pohang, South Korea, (4)Chonnam National University, Gwangju, South Korea, (5)University of Alaska Fairbanks, Fairbanks, AK, United States, (6)Korea Polar Research Institute, Incheon, South Korea, (7)Pacific Northwest National Laboratory, Richland, WA, United States
Successive cold winters in recent years have had critical social and economic impacts on the mid-latitude continents in the Northern Hemisphere. In this study, we show how Arctic sea-ice loss and cold winters in extra-polar regions are dynamically connected through the polar stratosphere. We find that decreased sea-ice cover during early winter months (November– December), especially over the Barents–Kara seas, enhances the upward propagation of planetary-scale waves with wavenumbers of 1 and 2, subsequently weakening the stratospheric polar vortex in mid-winter (January–February). The weakened polar vortex preferentially induces a negative phase of Arctic Oscillation at the surface, resulting in low temperatures in mid-latitudes.