Publikationsdatum:
2017-05-30
Beschreibung:
A set of relaxation experiments using the European Centre for Medium-Range Weather
Forecasts (ECMWF) atmospheric model is used to analyze the severe European winter of
1962/1963. We argue that the severe winter weather was associated with a wave train that
originated in the tropical Pacific sector (where weak La Ni˜na conditions were present)
and was redirected towards Europe, a process we suggest was influenced by the combined
effect of the strong easterly phase of the Quasi-Biennial Oscillation (QBO) and unusually
strong easterly winds in the upper equatorial troposphere that winter. A weak tendency
towards negative North Atlantic Oscillation (NAO) conditions in December, associated
with extratropical sea-surface temperature and sea-ice anomalies, might have acted as a
favourable preconditioning. The redirection of the wave train towards Europe culminated
in the stratospheric sudden warming at the end of January 1963. We argue that in February
the sudden warming event helped maintain the negative NAO regime, allowing the severe
weather to persist for a further month. A possible influence from the Madden–Julian
Oscillation, as well as a role for internal atmospheric variability, is noted.
Repository-Name:
EPIC Alfred Wegener Institut
Materialart:
Article
,
isiRev
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