Correlation between polar vortex movement patterns

and cold wave-affected areas in the Northen hemisphere is revealed

Is it possible to predict where a sudden, unpredictable blast of frigid Arctic air will land? The Ministry of Oceans and Fisheries (MOF, Minister MOON, Seong-Hyeok) announced that the Korea Polar Research Institute (KOPRI, President Kang Sung-Ho) unveiled their finding that cold wave-affected areas in the Northern hemisphere differ based on movement patterns of a polar vortex, and it is published in the scientific journal Frontiers in Earth Science last February.

The polar vortex is a blast of Arctic air swirling from west to east along the boundary between the cold air over the Arctic to the north and the milder air to the south. This vortex serves as barriers to trap and isolate cold Arctic air, preventing it from shifting southward. When the vortex is weakened due to factors such as global warming, parts of the vortex break off, bringing extremely cold weather down into the middle latitudes of the Northern hemisphere, where the Korean Peninsula is located.

Recently, a joint research team led by Dr. Kim Seong-Joong from KOPRI (in collaboration with the Pukyong National University) conducted a study on such polar vortex, and uncovered a new finding that affected areas, frequency, and intensity of cold wave in the Northern hemisphere vary depending on the movement patterns of the Arctic vortex.

Firstly, when the vortex is displaced off the North pole towards mid-latitudes (displacement type), the Eurasia Continent, including the Korean Peninsula, tends to experience a drop in ground temperature. For this reason, temperatures plummeted to nearly minus 20 degrees Celsius in Seoul in early and mid-January this year. Secondly, when the vortex is split into two and then displaced towards middle latitudes (split type), both the Eurasia Continent and North America witness a severe cold snap, as observed in February 2018*.

* The lowest temperatures over the Korean Peninsula and North America were recorded at -12.8℃ and -10.4℃, a drop of 6 to 7℃ from normal, respectively.

In addition to these already well-known two types, a new phenomenon of a polar vortex movement pattern is discovered by the research team. When the vortex moves towards mid-latitudes and then split into two, North America is affected by a strong cold wave while the Eurasian Continent is relatively warmer than other types. These kinds of abnormal polar vortex disruptions occur as the Arctic atmosphere becomes unstable, which will likely allow for more frequent vortex breakdowns due to higher temperatures in the Arctic caused by global warming.

Kim Chang-Kyun, Director General of Marine Policy Bureau of the MOF, said: “We have been committed to advancing Arctic research, including the findings of the Korea Polar Research Institute in 2017 that extreme weather phenomena in the middle latitudes are linked to Arctic amplification. Based on this, it was possible to establish the correlation between polar vortex movement patterns and cold wave-affected areas. We will continue to support Arctic research in identifying occurrence conditions for each abnormal movement of the Arctic vortex and enhancing the accuracy of predictability of cold wave.”