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Titel |
Impact of mineral dust on cloud formation in a Saharan outflow region |
VerfasserIn |
L. Smoydzin, A. Teller, H. Tost, M. Fnais, J. Lelieveld |
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. 23 ; Nr. 12, no. 23 (2012-12-03), S.11383-11393 |
Datensatznummer |
250011636
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Publikation (Nr.) |
copernicus.org/acp-12-11383-2012.pdf |
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Zusammenfassung |
We present a numerical modelling study investigating the impact of mineral
dust on cloud formation over the Eastern Mediterranean for two case studies:
(i) 25 September 2008 and (ii) 28/29 January 2003. In both cases dust plumes
crossed the Mediterranean and interacted with clouds forming along frontal
systems. For our investigation we used the fully online coupled model
WRF-chem.
The results show that increased aerosol concentrations due to the presence of
mineral dust can enhance the formation of ice crystals. This leads to slight
shifts of the spatial and temporal precipitation patterns compared to
scenarios where dust was not considered to act as ice nuclei. However, the
total amount of precipitation did not change significantly. The only
exception occurred when dust entered into an area of orographic ascent,
causing glaciation of the clouds, leading to a local enhancement of rainfall.
The impact of dust particles acting as giant cloud condensation nuclei on
precipitation formation was found to be small. Based on our simulations the
contribution of dust to the CCN population is potentially significant only
for warm phase clouds. Nevertheless, the dust-induced differences in the
microphysical structure of the clouds can contribute to a significant
radiative forcing, which is important from a climate perspective. |
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