|
Titel |
How unusual was autumn 2006 in Europe? |
VerfasserIn |
G. J. Oldenborgh |
Medientyp |
Artikel
|
Sprache |
Englisch
|
ISSN |
1814-9324
|
Digitales Dokument |
URL |
Erschienen |
In: Climate of the Past ; 3, no. 4 ; Nr. 3, no. 4 (2007-11-21), S.659-668 |
Datensatznummer |
250001180
|
Publikation (Nr.) |
copernicus.org/cp-3-659-2007.pdf |
|
|
|
Zusammenfassung |
The temperatures in large parts of Europe have been record high during the
meteorological autumn of 2006. Compared to 1961–1990, the 2 m temperature was
more than three degrees Celsius above normal from the North side of the Alps
to southern Norway. This made it by far the warmest autumn on record in the
United Kingdom, Belgium, the Netherlands, Denmark, Germany and Switzerland,
with the records in Central England going back to 1659, in the Netherlands to
1706 and in Denmark to 1768. The deviations were so large that under the
obviously false assumption that the climate does not change, the observed
temperatures for 2006 would occur with a probability of less than once every
10 000 years in a large part of Europe, given the distribution defined by the
temperatures in the autumn 1901–2005.
A better description of the temperature distribution is to assume that the
mean changes proportional to the global mean temperature, but the shape of
the distribution remains the same. This includes to first order the effects
of global warming. Even under this assumption the autumn temperatures were
very unusual, with estimates of the return time of 200 to 2000 years in this
region. The lower bound of the 95% confidence interval is more than 100 to
300 years.
Apart from global warming, linear effects of a southerly circulation are
found to give the largest contributions, explaining about half of the
anomalies. SST anomalies in the North Sea were also important along the
coast.
Climate models that simulate the current atmospheric circulation well
underestimate the observed mean rise in autumn temperatures. They do not
simulate a change in the shape of the distribution that would increase the
probability of warm events under global warming. This implies that the warm
autumn 2006 either was a very rare coincidence, or the local temperature rise
is much stronger than modelled, or non-linear physics that is missing from
these models increases the probability of warm extremes. |
|
|
Teil von |
|
|
|
|
|
|