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| Titel |
Incremental testing of the Community Multiscale Air Quality (CMAQ) modeling system version 4.7 |
| VerfasserIn |
K. M. Foley, S. J. Roselle, K. W. Appel, P. V. Bhave, J. E. Pleim, T. L. Otte, R. Mathur, G. Sarwar, J. O. Young, R. C. Gilliam, C. G. Nolte, J. T. Kelly, A. B. Gilliland, J. O. Bash |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1991-959X
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| Digitales Dokument |
URL |
| Erschienen |
In: Geoscientific Model Development ; 3, no. 1 ; Nr. 3, no. 1 (2010-03-26), S.205-226 |
| Datensatznummer |
250000802
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| Publikation (Nr.) |
 copernicus.org/gmd-3-205-2010.pdf |
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| Zusammenfassung |
| This paper describes the scientific and structural updates to the latest
release of the Community Multiscale Air Quality (CMAQ) modeling system
version 4.7 (v4.7) and points the reader to additional resources for further
details. The model updates were evaluated relative to observations and
results from previous model versions in a series of simulations conducted to
incrementally assess the effect of each change. The focus of this paper is on
five major scientific upgrades: (a) updates to the heterogeneous N2O5
parameterization, (b) improvement in the treatment of secondary organic
aerosol (SOA), (c) inclusion of dynamic mass transfer for coarse-mode
aerosol, (d) revisions to the cloud model, and (e) new options for the
calculation of photolysis rates. Incremental test simulations over the
eastern United States during January and August 2006 are evaluated to assess
the model response to each scientific improvement, providing explanations of
differences in results between v4.7 and previously released CMAQ model
versions. Particulate sulfate predictions are improved across all monitoring
networks during both seasons due to cloud module updates. Numerous updates to
the SOA module improve the simulation of seasonal variability and decrease
the bias in organic carbon predictions at urban sites in the winter. Bias in
the total mass of fine particulate matter (PM2.5) is dominated by
overpredictions of unspeciated PM2.5 (PMother) in the winter
and by underpredictions of carbon in the summer. The CMAQv4.7 model results
show slightly worse performance for ozone predictions. However, changes to
the meteorological inputs are found to have a much greater impact on ozone
predictions compared to changes to the CMAQ modules described here. Model
updates had little effect on existing biases in wet deposition predictions. |
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