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| Titel |
Evaluation of the atmospheric transport in a GCM using radon measurements: sensitivity to cumulus convection parameterization |
| VerfasserIn |
K. Zhang, H. Wan, M. Zhang, B. Wang |
| 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. 10 ; Nr. 8, no. 10 (2008-05-29), S.2811-2832 |
| Datensatznummer |
250006153
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| Publikation (Nr.) |
 copernicus.org/acp-8-2811-2008.pdf |
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| Zusammenfassung |
The radioactive species radon (222Rn) has long been used as a
test tracer for the numerical simulation of large scale transport
processes. In this study, radon transport experiments are carried
out using an atmospheric GCM with a finite-difference dynamical
core, the van Leer type FFSL advection algorithm, and two
state-of-the-art cumulus convection parameterization schemes.
Measurements of surface concentration and vertical distribution of
radon collected from the literature are used as references in model
evaluation.
The simulated radon concentrations using both convection schemes
turn out to be consistent with earlier studies with many other
models. Comparison with measurements indicates that at the locations
where significant seasonal variations are observed in reality, the
model can reproduce both the monthly mean surface radon
concentration and the annual cycle quite well. At those sites where
the seasonal variation is not large, the model is able to give a
correct magnitude of the annual mean. In East Asia, where radon
simulations are rarely reported in the literature, detailed analysis
shows that our results compare reasonably well with the
observations.
The most evident changes caused by the use of a different convection
scheme are found in the vertical distribution of the tracer. The
scheme associated with weaker upward transport gives higher radon
concentration up to about 6 km above the surface, and lower values
in higher altitudes. In the lower part of the atmosphere results
from this scheme does not agree as well with the measurements as the
other scheme. Differences from 6 km to the model top are even
larger, although we are not yet able to tell which simulation is
better due to the lack of observations at such high altitudes. |
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