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| Titel |
Regional climate model assessment of the urban land-surface forcing over central Europe |
| VerfasserIn |
P. Huszar, T. Halenka, M. Belda, M. Žák, K. Sindelarova, J. Miksovsky |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 14, no. 22 ; Nr. 14, no. 22 (2014-11-26), S.12393-12413 |
| Datensatznummer |
250119186
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| Publikation (Nr.) |
 copernicus.org/acp-14-12393-2014.pdf |
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| Zusammenfassung |
For the purpose of qualifying and quantifying the
climate impact of cities and urban surfaces in general on climate of
central Europe, the surface parameterization in regional climate
model RegCM4 has been extended with the Single-layer Urban Canopy
Model (SLUCM). A set of experiments was performed over the period of
2005–2009 for central Europe, either without considering urban
surfaces or with the SLUCM treatment. Results show a statistically
significant impact of urbanized surfaces on temperature (up to
1.5 K increase in summer) as well as on the boundary layer
height (increases up to 50 m). Urbanization further
influences surface wind with a winter decrease up to
−0.6 m s−1, though both increases and decreases were
detected in summer depending on the location relative to the cities
and daytime (changes up to 0.3 m s−1). Urban surfaces
significantly reduce the humidity over the
surface. This impacts the simulated summer precipitation rate,
showing a decrease over cities of up to
−2 mm day−1. Significant temperature increases are
simulated over higher altitudes as well, not only within the urban
canopy layer. With the urban parameterization, the climate model
better describes the diurnal temperature variation, reducing the
cold afternoon and evening bias of RegCM4.
Sensitivity experiments were carried out to quantify the response of
the meteorological conditions to changes in the parameters specific
to the urban environment, such as street width, building height,
albedo of the roofs and anthropogenic heat release. The results
proved to be rather robust and the choice of the key SLUCM
parameters impacts them only slightly (mainly temperature, boundary
layer height and wind velocity).
Statistically significant impacts are modelled not only over large
urbanized areas, but the influence of the cities is also evident
over rural areas without major urban surfaces. It is shown that this
is the result of the combined effect of the distant influence of the
cities and the influence of the minor local urban surface coverage. |
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