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| Titel |
The Fully Online Integrated Model System COSMO-ART to Simulate Interactions of Aerosols, Clouds, and Radiation on the Regional to the Continental Scale |
| VerfasserIn |
Bernhard Vogel, Max Bangert, Heike Vogel, Rayk Rinke, Kristina Lundgren |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250046982
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| Zusammenfassung |
| In order to quantify the feedback processes between aerosols and the state of the
atmosphere on the continental to regional scale the fully online integrated model
system COSMO-ART with two-way interactions between different atmospheric
processes was developed (Vogel et al., 2009, Bangert et al., 2010). The operational
weather forecast model of the Deutscher Wetterdienst was extended to treat secondary
aerosols as well as directly emitted components like soot, mineral dust, sea salt and
biological material. Secondary aerosol particles are formed from the gas phase.
Therefore, a complete gas phase mechanism (RADMKA) is included in COSMO-ART.
New methods to calculate efficiently the photolysis frequencies and the radiative
fluxes based on the actual aerosol load were developed based on the GRAALS
radiation scheme (Geleyn and Ritter, 1992). Modules for the emissions of biogenic
precursors of aerosols, mineral dust, sea salt, biomass burning aerosol and pollen
grains are included. Processes as coagulation, condensation (including the explicit
treatment of the soot aging; Riemer et al., 2004), deposition, sedimentation, and
washout are taken into account. To simulate the impact of aerosol particles on cloud
formation and precipitation the two moment scheme of Seifert and Beheng (2001)
is used. The activation of aerosol particles is based on Koehler theory using the
parameterization of Abdul-Razzak and Ghan (2000). Recently, the treatment of the
interaction of aerosol particles and cloud microphysics was extended (Bangert et al.,
2010). The activation parameterization considers the CCN adsorption activation of
dust particles (Kumar et al. 2009, Barahona et al. 2010) and the competition for
water with the activation of soluble particles and in addition the ice nucleation
parameterization of Barahona and Nenes 2009. The latter includes the competition effects
of heterogeneous freezing involving dust and BC with homogenous freezing of
aerosol.
In May 2008 a strong Saharan dust outbreak covered large areas over Europe.
During this time period the operational weather forecast models over predicted the
observed 2 m temperature. Applications of COSMO-ART demonstrate that the
treatment of the two way interactions improves the weather forecast. Sensitivity runs
will show the contribution of direct and indirect effects to these improvements. |
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