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| Titel |
Tropospheric aerosol microphysics simulation with assimilated meteorology: model description and intermodel comparison |
| VerfasserIn |
W. Trivitayanurak, P. J. Adams, D. V. Spracklen, K. S. Carslaw |
| 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 ; 8, no. 12 ; Nr. 8, no. 12 (2008-06-24), S.3149-3168 |
| Datensatznummer |
250006223
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| Publikation (Nr.) |
 copernicus.org/acp-8-3149-2008.pdf |
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| Zusammenfassung |
| We implement the TwO-Moment Aerosol Sectional (TOMAS) microphysics module
into GEOS-CHEM, a CTM driven by assimilated meteorology. TOMAS has 30 size
sections covering 0.01–10 μm diameter with conservation equations
for both aerosol mass and number. The implementation enables GEOS-CHEM to
simulate aerosol microphysics, size distributions, mass and number
concentrations. The model system is developed for sulfate and sea-salt
aerosols, a year-long simulation has been performed, and results are
compared to observations. Additionally model intercomparison was carried out
involving global models with sectional microphysics: GISS GCM-II' and
GLOMAP. Comparison with marine boundary layer observations of CN10 and
CCN(0.2%) shows that all models perform well with average errors of 30–50%.
However, all models underpredict CN10 by up to 42% between
15° S and 45° S while overpredicting CN10 up to 52% between
45° N and 60° N, which could be due to the sea-salt emission
parameterization and the assumed size distribution of primary sulfate
emission, in each case respectively. Model intercomparison at the surface
shows that GISS GCM-II' and GLOMAP, each compared against GEOS-CHEM, both
predict 40% higher CN10 and predict 20% and 30% higher CCN(0.2%)
on average, respectively. Major discrepancies are due to different emission
inventories and transport. Budget comparison shows GEOS-CHEM predicts the
lowest global CCN(0.2%) due to microphysical growth being a factor of 2
lower than other models because of lower SO2 availability. These
findings stress the need for accurate meteorological inputs, updated
emission inventories, and realistic clouds and oxidant fields when
evaluating global aerosol microphysics models. |
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