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| Titel |
Influence of meteorological patterns on global dimming and brightening in Europe |
| VerfasserIn |
Kajsa Parding, Beate Liepert, Laura Hinkelman, Thomas Ackerman, Jan Asle Olseth, Knut-Frode Dagestad |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250083001
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| Zusammenfassung |
| Observational studies have found interdecadal variability in incoming solar radition at the
Earth’s surface, known as global dimming and brightening. In Europe, the reported trends are
around -3Wm-2/decade for 1950-1980, and +2Wm-2/decade for 1980-2000, though the
representativeness of these numbers is an open issue. Global dimming and brightening has
been linked to changes in aerosol and clouds.
On short time scales, at mid latitudes, clouds related to synoptic weather strongly
influence atmospheric transmittance of solar radiation. In this work, we investigate if changes
in synoptic weather patterns can influence dimming and brightening. Normalized
observations of surface solar radiation are fitted against the monthly frequency of occurrence
of 29 daily weather patterns (Grosswetterlagen, GWL). A trend difference index, Bw, is
developed to compare the decadal scale variability of modeled and observed insolation. Trend
analysis of surface insolation data from the Global Energy Balance Archive (GEBA) shows
that there are regional differences in global dimming and brightening. In many of the
European GEBA sites, a large part of the monthly solar radiation variability can be explained
by a linear combination of GWL patterns. In some locations, the long term trends can
also be partly explained by changes in weather patterns. It is likely that in parts of
Europe, some of the global dimming and brightening signal is a consequence of
fluctuations in meteorological patterns, rather than due to changing aerosol loadings. |
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