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| Titel |
Offsetting effects of aerosols on Arctic and global climate in the late 20th century |
| VerfasserIn |
Q. Yang, C. M. Bitz, S. J. Doherty |
| 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. 8 ; Nr. 14, no. 8 (2014-04-22), S.3969-3975 |
| Datensatznummer |
250118628
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| Publikation (Nr.) |
 copernicus.org/acp-14-3969-2014.pdf |
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| Zusammenfassung |
| We examine the impacts of atmospheric aerosols on Arctic and global climate
using a series of 20th century transient simulations from Community Climate
System Model version 4 (CCSM4). We focus on the response of surface air
temperature to the direct radiative forcing driven by changes in sulfate and
black carbon (BC) concentrations from 1975 to 2005 and we also examine the
response to changes in sulfate, BC, and organic carbon (OC) aerosols
collectively. The direct forcing from sulfate dominates the aerosol climate
effect. Globally averaged, simultaneous changes in all three aerosols produce
a cooling trend of 0.015 K decade−1 during the period 1975–2005. In
the Arctic, surface air temperature has large spatial variations in response
to changes in aerosol concentrations. Over the European Arctic, aerosols
induce about 0.6 K decade−1 warming, which is about 1.8 K warming
over the 30-year period. This warming is triggered mainly by the reduction in
sulfate and BC emissions over Europe since the 1970s and is reinforced by sea
ice loss and a strengthening in atmospheric northward heat transport. Changes
in sulfate concentrations account for about two thirds of the warming and BC
for the remaining one third. Over the Siberian and North American Arctic,
surface air temperature is likely influenced by changes in aerosol
concentrations over Asia. An increase in sulfate optical depth over Asia
induces a large cooling while an increase in BC over Asia causes a
significant warming. |
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