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| Titel |
Aerosol indirect forcing in a global model with particle nucleation |
| VerfasserIn |
M. Wang, J. E. Penner |
| 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 ; 9, no. 1 ; Nr. 9, no. 1 (2009-01-14), S.239-260 |
| Datensatznummer |
250006643
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| Publikation (Nr.) |
 copernicus.org/acp-9-239-2009.pdf |
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| Zusammenfassung |
| The number concentration of cloud condensation nuclei (CCN) formed as a
result of anthropogenic emissions is a key uncertainty in the study of
aerosol indirect forcing and global climate change. Here, we use a global
aerosol model that includes an empirical boundary layer nucleation
mechanism, the use of primary-emitted sulfate particles to represent
sub-grid scale nucleation, as well as binary homogeneous nucleation to
explore how nucleation affects the CCN concentration and the first aerosol
indirect effect (AIE). The inclusion of the boundary layer nucleation scheme
increases the global average CCN concentrations in the boundary layer by
31.4% when no primary-emitted sulfate particles are included and by
5.3% when they are included. Particle formation with the boundary layer
nucleation scheme decreases the first indirect forcing over ocean, and
increases the first indirect forcing over land when primary sulfate
particles are included. This suggests that whether particle formation from
aerosol nucleation increases or decreases aerosol indirect effects largely
depends on the relative change of primary particles and SO2 emissions from
the preindustrial to the present day atmosphere. Including primary-emitted
sulfate particle significantly increases both the anthropogenic fraction of
CCN concentrations and the first aerosol indirect forcing. The forcing from
various treatments of aerosol nucleation ranges from −1.22 to −2.03 w/m2.
This large variation shows the importance of better quantifying
aerosol nucleation mechanisms for the prediction of CCN concentrations and
aerosol indirect effects. |
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