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Titel |
Impact of urban parameterization on high resolution air quality forecast with the GEM – AQ model |
VerfasserIn |
J. Struzewska, J. W. Kaminski |
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 ; 12, no. 21 ; Nr. 12, no. 21 (2012-11-07), S.10387-10404 |
Datensatznummer |
250011572
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Publikation (Nr.) |
copernicus.org/acp-12-10387-2012.pdf |
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Zusammenfassung |
The aim of this study is to assess the impact of urban cover on
high-resolution air quality forecast simulations with the GEM-AQ (Global
Environmental Multiscale and Air Quality) model. The impact of urban area on
the ambient atmosphere is non-stationary, and short-term variability of
meteorological conditions may result in significant changes of the observed
intensity of urban heat island and pollutant concentrations. In this study
we used the Town Energy Balance (TEB) parameterization to represent urban
effects on modelled meteorological and air quality parameters at the final
nesting level with horizontal resolution of ~5 km over Southern
Poland. Three one-day cases representing different meteorological conditions
were selected and the model was run with and without the TEB
parameterization. Three urban cover categories were used in the TEB
parameterization: mid-high buildings, very low buildings and low density
suburbs. Urban cover layers were constructed based on an area fraction of
towns in a grid cell. To analyze the impact of urban parameterization on
modelled meteorological and air quality parameters, anomalies in the lowest
model layer for the air temperature, wind speed and pollutant concentrations
were calculated. Anomalies of the specific humidity fields indicate that the
use of the TEB parameterization leads to a systematic reduction of moisture
content in the air. Comparison with temperature and wind speed measurements
taken at urban background monitoring stations shows that application of
urban parameterization improves model results. For primary pollutants the
impact of urban areas is most significant in regions characterized with high
emissions. In most cases the anomalies of NO2 and CO concentrations
were negative. This reduction is most likely caused by an enhanced vertical
mixing due to elevated surface temperature and modified vertical stability. |
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