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| Titel |
Shortwave Radiative Impacts of Atmospheric Dust Burden on the Earth Climate of the Last Glacial Cycle Simulated with CLIMBER-2 |
| VerfasserIn |
E. Bauer, V. Petoukhov, A. Ganopolski |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250019735
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| Zusammenfassung |
| Mineral dust particles provide the dominant contribution to the aerosol mass
in the atmosphere while showing enormous variations in space and time. Dust
deposition flux data range over more than four orders of magnitude. The
largest values are reconstructed from Asian loess areas, followed by values
from the Arabian Sea and the low latitudes in the eastern Atlantic, and the
smallest values are from Antarctica. In general, deposition fluxes are about
one order of magnitude larger in glacial periods than during interglacials. We
present a dust cycle scheme for the CLIMBER-2 Earth system model of
intermediate complexity for studying large-scale changes of the climatic
impact of mineral dust. The scheme describes in a simple manner processes of
dust emission, transport and deposition. We show that simulated and
reconstructed time series of dust deposition fluxes for Antarctica agree
reasonably well over the last glacial cycle. In the next step we account for
the radiative forcing caused by dust particles with radii in the range of the
solar wavelengths. With relevant optical parameters, the atmospheric dust
burden leads to a global cooling that is concentrated in low and middle
latitudes. Subsequently, precipitation decreases, potential dust source
regions grow and the dust emission increases. This positive feedback in the
dust cycle simulation enhances the dust emission considerably in glacial
periods and thus brings long-term series of dust deposition flux from
simulation and reconstruction into closer agreement. |
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