Linkages between Arctic sea-ice changes and atmospheric circulation patterns in reanalysis data and model simulations

• Main Authors: Jaiser, Ralf, Handorf, Dörthe, Crasemann, Berit, Romanowsky, Erik, Dethloff, Klaus, Nakamura, Tetsu, Ukita, Jinro, Yamazaki, Koji
• Format: Conference Object
• Language: unknown
• Published: 2017
• Subjects: Arctic; Global warming; North Atlantic; North Atlantic oscillation; Sea ice
• Online Access: https://epic.awi.de/id/eprint/45773/; https://hdl.handle.net/10013/epic.51982

Observed global warming trends have their maximum in Arctic regions, a phenomenon referred to as Arctic Amplification. Consequently, Arctic sea ice shows a strong decreasing trend. These changes imprint modifications on atmospheric flow patterns not only in Arctic regions themselves. Changes of teleconnections and planetary scale motions like Rossby waves affect mid-latitude climate as well. The application of a cluster analysis revealed two circulation patterns that occur more frequently for low Arctic sea ice conditions: a Scandinavian blocking in December and January and a negative North Atlantic Oscillation pattern in February and March. The first pattern is related to enhanced upward wave propagation in this region and period. These waves reach the stratosphere and disturb the polar vortex. The downward response is again linked to the higher frequency of negative NAO events in late winter. These results are consistent in reanalysis data and model simulations.