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| Titel |
The complex response of Arctic aerosol to sea-ice retreat |
| VerfasserIn |
J. Browse, K. S. Carslaw, G. W. Mann, C. E. Birch, S. R. Arnold, C. Leck |
| 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 ; 14, no. 14 ; Nr. 14, no. 14 (2014-07-29), S.7543-7557 |
| Datensatznummer |
250118906
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| Publikation (Nr.) |
 copernicus.org/acp-14-7543-2014.pdf |
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| Zusammenfassung |
| Loss of summertime Arctic sea ice will lead to a large increase in the
emission of aerosols and precursor gases from the ocean surface. It has been
suggested that these enhanced emissions will exert substantial aerosol
radiative forcings, dominated by the indirect effect of aerosol on clouds.
Here, we investigate the potential for these indirect forcings using a global
aerosol microphysics model evaluated against aerosol observations from the Arctic Summer
Cloud Ocean Study (ASCOS) campaign to examine the response of Arctic cloud condensation nuclei
(CCN) to sea-ice retreat. In response to a complete loss of summer ice, we
find that north of 70° N emission fluxes of sea salt, marine
primary organic aerosol (OA) and dimethyl sulfide increase by a factor of
~ 10, ~ 4 and ~ 15 respectively. However, the CCN response is
weak, with negative changes over the central Arctic Ocean. The weak response
is due to the efficient scavenging of aerosol by extensive drizzling
stratocumulus clouds. In the scavenging-dominated Arctic environment, the
production of condensable vapour from oxidation of dimethyl sulfide grows
particles to sizes where they can be scavenged. This loss is not sufficiently
compensated by new particle formation, due to the suppression of nucleation
by the large condensation sink resulting from sea-salt and primary OA
emissions. Thus, our results suggest that increased aerosol emissions will
not cause a climate feedback through changes in cloud microphysical and
radiative properties. |
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