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| Titel |
Comparison of MADE3-simulated and observed aerosol distributions with a focus on aerosol vertical profiles |
| VerfasserIn |
Christopher Kaiser, Johannes Hendricks, Mattia Righi, Patrick Jöckel |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250127741
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| Publikation (Nr.) |
 EGU/EGU2016-7648.pdf |
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| Zusammenfassung |
| The reliability of aerosol radiative forcing estimates from climate models depends on the
accuracy of simulated global aerosol distribution and composition, as well as on the
models’ representation of the aerosol–cloud and aerosol–radiation interactions. To
help improve on previous modeling studies, we recently developed the new aerosol
microphysics submodel MADE3 that explicitly tracks particle mixing state in the Aitken,
accumulation, and coarse mode size ranges. We implemented MADE3 into the
global atmospheric chemistry general circulation model EMAC and evaluated it by
comparison of simulated aerosol properties to observations. Compared properties include
continental near-surface aerosol component concentrations and size distributions,
continental and marine aerosol vertical profiles, and nearly global aerosol optical
depth.
Recent studies have shown the specific importance of aerosol vertical profiles for
determination of the aerosol radiative forcing. Therefore, our focus here is on the evaluation
of simulated vertical profiles. The observational data is taken from campaigns between 1990
and 2011 over the Pacific Ocean, over North and South America, and over Europe. The
datasets include black carbon and total aerosol mass mixing ratios, as well as aerosol particle
number concentrations.
Compared to other models, EMAC with MADE3 yields good agreement with the
observations – despite a general high bias of the simulated mass mixing ratio profiles.
However, BC concentrations are generally overestimated by many models in the upper
troposphere. With MADE3 in EMAC, we find better agreement of the simulated BC profiles
with HIPPO data than the multi-model average of the models that took part in the AeroCom
project.
There is an interesting difference between the profiles from individual campaigns and
more “climatological” datasets. For instance, compared to spatially and temporally localized
campaigns, the model simulates a more continuous decline in both total aerosol and black
carbon mass mixing ratio with altitude than found in the observations. In contrast, measured
profiles from the HIPPO project are qualitatively captured well. Similar conclusions hold for
the comparison of simulated and measured aerosol particle number concentrations. On the
one hand, these results exemplify the difficulty in evaluating the representativeness of the
simulated global climatological state of the aerosol by means of comparison with
individually measured vertical profiles. On the other hand, it highlights the value of
aircraft campaigns with large spatial and temporal coverage for model evaluation. |
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