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| Titel |
A GCM study of organic matter in marine aerosol and its potential contribution to cloud drop activation |
| VerfasserIn |
G. J. Roelofs |
| 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 ; 8, no. 3 ; Nr. 8, no. 3 (2008-02-13), S.709-719 |
| Datensatznummer |
250005555
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| Publikation (Nr.) |
 copernicus.org/acp-8-709-2008.pdf |
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| Zusammenfassung |
| With the global aerosol-climate model ECHAM5-HAM we investigate the
potential influence of organic aerosol originating from the ocean on aerosol
mass and chemical composition and the droplet concentration and size of
marine clouds. We present sensitivity simulations in which the uptake of
organic matter in the marine aerosol is prescribed for each aerosol mode
with varying organic mass and mixing state, and with a geographical
distribution and seasonality similar to the oceanic emission of dimethyl
sulfide. Measurements of aerosol mass, aerosol chemical composition and
cloud drop effective radius are used to assess the representativity of the
model initializations. Good agreement with the measurements is obtained when
organic matter is added to the Aitken, accumulation and coarse modes
simultaneously. Representing marine organics in the model leads to higher
cloud drop number concentrations and thus smaller cloud drop effective
radii, and this improves the agreement with measurements. The mixing state
of the organics and the other aerosol matter, i.e. internal or external
depending on the formation process of aerosol organics, is an important
factor for this. We estimate that globally about 75 Tg C yr−1 of
organic matter from marine origin enters the aerosol phase, with comparable
contributions from primary emissions and secondary organic aerosol
formation. |
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