Publication Date:
2018-02-14
Description:
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).
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
isiRev
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