Extreme cyclone events in the Arctic: Wintertime variability and trends

• Published in: Environmental Research Letters
• Main Authors: A Rinke, M Maturilli, R M Graham, H Matthes, D Handorf, L Cohen, S R Hudson, J C Moore
• Format: Article in Journal/Newspaper
• Language: English
• Published: IOP Publishing 2017
• Subjects: extreme events; cyclones; Arctic; atmospheric circulation; sea-ice changes; Environmental technology. Sanitary engineering; TD1-1066; Environmental sciences; GE1-350; Science; Q; Physics; QC1-999; Ny-Ålesund; North Atlantic; Ny Ålesund; Sea ice
• Online Access: https://doi.org/10.1088/1748-9326/aa7def; https://doaj.org/article/1f89ba8562264f1e87ad6ee980e379b6

Typically 20–40 extreme cyclone events (sometimes called ‘weather bombs’) occur in the Arctic North Atlantic per winter season, with an increasing trend of 6 events/decade over 1979–2015, according to 6 hourly station data from Ny-Ålesund. This increased frequency of extreme cyclones is consistent with observed significant winter warming, indicating that the meridional heat and moisture transport they bring is a factor in rising temperatures in the region. The winter trend in extreme cyclones is dominated by a positive monthly trend of about 3–4 events/decade in November–December, due mainly to an increasing persistence of extreme cyclone events. A negative trend in January opposes this, while there is no significant trend in February. We relate the regional patterns of the trend in extreme cyclones to anomalously low sea-ice conditions in recent years, together with associated large-scale atmospheric circulation changes such as ‘blockinglike’ circulation patterns (e.g. Scandinavian blocking in December and Ural blocking during January–February).