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Titel |
Black carbon in the atmosphere and snow, from pre-industrial times until present |
VerfasserIn |
R. B. Skeie, T. Berntsen, G. Myhre, C. A. Pedersen, J. Ström, S. Gerland, J. A. Ogren |
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 ; 11, no. 14 ; Nr. 11, no. 14 (2011-07-18), S.6809-6836 |
Datensatznummer |
250009917
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Publikation (Nr.) |
copernicus.org/acp-11-6809-2011.pdf |
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Zusammenfassung |
The distribution of black carbon (BC) in the atmosphere and the deposition
of BC on snow surfaces since pre-industrial time until present are modelled
with the Oslo CTM2 model. The model results are compared with observations
including recent measurements of BC in snow in the Arctic. The global mean
burden of BC from fossil fuel and biofuel sources increased during two
periods. The first period, until 1920, is related to increases in emissions
in North America and Europe, and the last period after 1970 are related
mainly to increasing emissions in East Asia. Although the global burden of
BC from fossil fuel and biofuel increases, in the Arctic the maximum
atmospheric BC burden as well as in the snow was reached in 1960s, with a
slight reduction thereafter. The global mean burden of BC from open biomass
burning sources has not changed significantly since 1900. With current
inventories of emissions from open biomass sources, the modelled burden of
BC in snow and in the atmosphere north of 65° N is small compared to the
BC burden of fossil fuel and biofuel origin. From the concentration changes
radiative forcing time series due to the direct aerosol effect as well as
the snow-albedo effect is calculated for BC from fossil fuel and biofuel.
The calculated radiative forcing in 2000 for the direct aerosol effect is
0.35 W m−2 and for the snow-albedo effect 0.016 W m−2 in this
study. Due to a southward shift in the emissions there is an increase in the
lifetime of BC as well as an increase in normalized radiative forcing,
giving a change in forcing per unit of emissions of 26 % since 1950. |
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