The extraordinarily strong and cold polar vortex in the early northern winter 2015/16

• Published in: Geophysical Research Letters
• Main Authors: Matthias, Vivien, Dörnbrack, Andreas, Stober, Gunter
• Format: Other Non-Article Part of Journal/Newspaper
• Language: German
• Published: Wiley 2016
• Subjects: Verkehrsmeteorologie; Arctic
• Online Access: https://elib.dlr.de/108690/; https://elib.dlr.de/108690/1/Matthias_et_al-2016-Geophysical_Research_Letters.pdf; https://doi.org/10.1002/2016GL071676

The Arctic polar vortex in the early winter 2015/16 was the strongest and coldest o f the la st 68 years. Using global reanalysis data, satellite observations, and mesospheric radar wind measurements over northern Scandinavia we investigate the characteristics of the early sta g e polar vortex and relate them to previous winters. We found a correlation between the planetary wave (PW) activity and the strength and temperature of the northern polar vor- tex in the stratosphere and mesosphere. In Nov/D ec 2015, a reduced PW generation in the troposphere and a stronger PW filtering in the troposphere and stratosphere, caused by stronger zonal winds in mid-latitudes, resulted in a stronger polar vortex. Thi s effect was strengthened by the equator ward shift of PWs due to the strong zonal wind in polar latitudes resulting in a southward shift of the Eliassen-Palm flux divergence and hence inducinga decreased deceleration of th e polar vortex by PWs.