A long-term climatology of North Atlantic polar lows

• Published in: Geophysical Research Letters
• Main Authors: Zahn, M., Storch, H.v.
• Format: Article in Journal/Newspaper
• Language: English
• Published: AGU 2008
• Subjects: info:eu-repo/classification/ddc/551; North Atlantic; Subarctic
• Online Access: https://publications.hereon.de/id/27110; https://publications.hzg.de/id/27110; http://www.hzg.de/imperia/md/content/gkss/zentrale_einrichtungen/bibliothek/journals/2008/Zahn-georeslet.pdf

A dynamical downscaling of the 6-hourly 1948–2006 NCEP/NCAR re-analyses for the subarctic region of the North Atlantic has been used to derive a climatology of polar lows by means of a tracking algorithm based on the simulated bandpass filtered MSLP-fields. This climatology is consistent with the limited observational evidence in terms of frequency and spatial distribution. The climatology exhibits strong year-to-year variability but weak decadal variability and a negligible trend. A Canonical Correlation Analysis describes the conditioning of the formation of polar lows by characteristic meridional seasonal mean flow regimes, which favor cold air outbreaks and upper air troughs.