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| Titel |
Comparing two years of Saharan dust source activation obtained by regional modelling and satellite observations |
| VerfasserIn |
I. Tegen, K. Schepanski, B. Heinold |
| 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 ; 13, no. 5 ; Nr. 13, no. 5 (2013-03-01), S.2381-2390 |
| Datensatznummer |
250018460
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| Publikation (Nr.) |
 copernicus.org/acp-13-2381-2013.pdf |
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| Zusammenfassung |
| A regional-scale dust model is used to simulate Saharan dust emissions and
atmospheric distributions in the years 2007 and 2008. The model results are
compared to dust source activation events compiled from infrared dust index
imagery from the geostationary Meteosat Second Generation (MSG) satellite.
The observed morning maximum in dust source activation frequencies indicates
that the breakdown of nocturnal low level jets is an important mechanism for
dust source activation in the Sahara. The comparison shows that the time of
the day of the onset of dust emission is delayed in the model compared to
the observations. Also, the simulated number of dust emission events
associated with nocturnal low level jets in mountainous regions is
underestimated in the model. The MSG dust index observations indicate a
strong increase in dust source activation frequencies in the year 2008
compared to 2007. The difference between the two years is less pronounced in
the model. Observations of dust optical thickness, e.g. at stations of the
sunphotometer network AERONET, do not show such increase, in agreement with
the model results. This indicates that the number of observed dust
activation events is only of limited use for estimating actual dust emission
fluxes in the Sahara. The ability to reproduce interannual variability of
Saharan dust with models remains an important challenge for understanding
the controls of the atmospheric dust load. |
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