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| Titel |
Validating CM-SAF |
| VerfasserIn |
J. Kalisch, A. Macke, R. Hollmann |
| Konferenz |
EGU General Assembly 2009
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250024243
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| Zusammenfassung |
| The present work investigated the quality of the downward shortwave (DSR) and longwave
(DLR) radiation retrieved by Meteosat Second Generation (MSG) algorithms for the Atlantic
sea surface.
The datasets of two transatlantic research cruises were chosen as an ideal basis to be
compared with the MSG products for incoming surface radiation fluxes of Meteosat-8 and
Meteosat-9. Onboard the research vessels Ioffe and Polarstern high quality in situ
measurements for DSR and DLR fluxes were performed. Additionally the cloudy sky has
been monitored permanently by means of an automated full sky imager, and meteorological
standard measurements were performed. This allowed a comprehensive evaluation of the
skills of MSG radiative retrievals in different climate zones and under various cloud and
weather conditions.
The incoming DSR was retrieved by MSG with a positive bias of 2.77Wm-2 to
22.23Wm-2 depending on the cruise. The bias for the DLR was -1.73Wm-2 to
2.76Wm-2. The differences between the two cruises were influenced by its distribution of
typical weather scenarios. Significant differences of Meteosat-8 and Meteosat-9 were shown
for the same in situ dataset.
In general DSR and DLR for clear sky conditions are captured with a high accuracy. Largest
errors occur for retrieved insolation of fast fluctating broken cloud conditions, though in
average the MSG algorithms matched well. Semitransparent cirrus was found to cause a
negative bias for the retrieved DSR. In tropics and subtropics the errors for DLR are reduced
compared to higher latitudes. A significant dependency of errors of both the DSR and the
DLR on the solar elevation, the humidity near the surface, SST and the shift of day and night
was not found. |
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