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Titel |
Hemispheric transport and influence of meteorology on global aerosol climatology |
VerfasserIn |
T. L. Zhao, S. L. Gong, P. Huang, D. Lavoué |
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. 16 ; Nr. 12, no. 16 (2012-08-22), S.7609-7624 |
Datensatznummer |
250011406
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Publikation (Nr.) |
copernicus.org/acp-12-7609-2012.pdf |
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Zusammenfassung |
Based on a 10-yr simulation with the global air quality modeling system
GEM-AQ/EC, the northern hemispheric aerosol transport with the inter-annual
and seasonal variability as well as the mean climate was investigated. The
intercontinental aerosol transport is predominant in the zonal direction from
west to east with the ranges of inter-annual variability between 14% and
63%, and is 0.5–2 orders of magnitude weaker in the meridional direction
but with larger inter-annual variability. The aerosol transport is found to
fluctuate seasonally with a factor of 5–8 between the maximum in late winter
and spring and the minimum in late summer and fall. Three meteorological
factors controlling the intercontinental aerosol transport and its
inter-annual variations are identified from the modeling results: (1)
Anomalies in the mid-latitude westerlies in the troposphere. (2) Variations
of precipitation over the intercontinental transport pathways and (3) Changes
of meteorological conditions within the boundary layer. Changed only by the
meteorology, the aerosol column loadings in the free troposphere over the
source regions of Europe, North America, South and East Asia vary
inter-annually with the highest magnitudes of 30–37% in January and
December and the lowest magnitudes of 16–20% in August and September, and
the inter-annual aerosol variability within the boundary layer influencing
the surface concentrations with the magnitudes from 6% to 20% is more
region-dependent. As the strongest climatic signal, the El Niño-Southern
Oscillation (ENSO) can lead the anomalies in the intercontinental aerosols in
El Niño- and La Niña-years respectively with the strong and weak
transport of the mid-latitude westerlies and the low latitude easterlies in
the Northern Hemisphere (NH). |
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