HR: 17:15h
AN: A44B-06    [Abstracts]
TI: The Microphysical Coupling of Natural and Anthropogenic Aerosol Cycles
AU: * Stier, P
EM: stier@dkrz.de
AF: Max Planck Institute for Meteorology, Bundesstrasse 53, Hamburg, 20146 Germany
AU: Feichter, J
EM: feichter@dkrz.de
AF: Max Planck Institute for Meteorology, Bundesstrasse 53, Hamburg, 20146 Germany
AU: Kinne, S
EM: kinne@dkrz.de
AF: Max Planck Institute for Meteorology, Bundesstrasse 53, Hamburg, 20146 Germany
AU: Kloster, S
EM: kloster@dkrz.de
AF: Max Planck Institute for Meteorology, Bundesstrasse 53, Hamburg, 20146 Germany
AU: Vignati, E
EM: elisabetta.vignati@jrc.it
AF: Institute for the Environment and Sustainability, European Commission Joint Research Centre, DG JRC TP 280, Ispra, 21020 Italy
AU: Wilson, J
EM: julian.wilson@jrc.it
AF: Institute for the Environment and Sustainability, European Commission Joint Research Centre, DG JRC TP 280, Ispra, 21020 Italy
AB: Aerosols are thought to play an important role in the global climate system. However, their effects on the radiation budget and even their global distribution and composition are not understood satisfactorily. A major uncertainty is the anthropogenic contribution of the global aerosol distribution and eventually the anthropogenic impact on aerosol radiative effects. Up to now, most multi-component aerosol modules in global circulation models approach this issue with a bulk approach predicting the mass of the aerosol components independently as external mixture. However, observations show that the mixing state of the global aerosol system is highly variable with a large internally mixed contribution. These results underscore that the aerosol components cannot be simulated independently and that aerosol aging processes need to be taken into account. The new aerosol-climate modelling system ECHAM5-HAM predicts size-distribution, composition, and mixing state of an ensemble of partly internally mixed modes for the components sulfate, black carbon, organic carbon, sea salt and dust. The microphysical approach includes the aging of aerosols via condensation, coagulation, and cloud processing. Results from a series of nudged simulations will be presented, in which we investigate the microphysical coupling of natural and anthropogenic aerosol cycles by the inclusion / omission of emissions of specific aerosol sources. Unlike the almost linear relationship of emissions and aerosol load in the bulk modelling approach, our results show that the microphysical coupling induces non-linearity in the system. In addition, the size-distribution and therefore the aerosol number concentrations are coupled non-linearly to the emissions with consequences for the direct and indirect aerosol radiative effects.
DE: 3309 Climatology (1620)
DE: 1610 Atmosphere (0315, 0325)
DE: 1615 Biogeochemical processes (4805)
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0322 Constituent sources and sinks
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting