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| Titel |
Arctic Clouds and Surface Radiation – a critical comparison of satellite retrievals and the ERA-Interim reanalysis |
| VerfasserIn |
M. Zygmuntowska, T. Mauritsen, J. Quaas, L. Kaleschke |
| 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 ; 12, no. 14 ; Nr. 12, no. 14 (2012-07-27), S.6667-6677 |
| Datensatznummer |
250011350
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| Publikation (Nr.) |
 copernicus.org/acp-12-6667-2012.pdf |
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| Zusammenfassung |
| Clouds regulate the Earth's radiation budget, both by reflecting part of the
incoming sunlight leading to cooling and by absorbing and emitting infrared
radiation which tends to have a warming effect. Globally averaged, at the top
of the atmosphere the cloud radiative effect is to cool the climate, while at
the Arctic surface, clouds are thought to be warming. Here we compare a
passive instrument, the AVHRR-based retrieval from CM-SAF, with recently
launched active instruments onboard CloudSat and CALIPSO and the widely used
ERA-Interim reanalysis. We find that in particular in winter months the three
data sets differ significantly. While passive satellite instruments have
serious difficulties, detecting only half the cloudiness of the modeled
clouds in the reanalysis, the active instruments are in between. In summer,
the two satellite products agree having monthly means of 70–80 percent, but
the reanalysis are approximately ten percent higher. The monthly mean long-
and shortwave components of the surface cloud radiative effect obtained from
the ERA-Interim reanalysis are about twice that calculated on the basis of
CloudSat's radar-only retrievals, while ground based measurements from SHEBA
are in between. We discuss these differences in terms of instrument-,
retrieval- and reanalysis characteristics, which differ substantially between
the analyzed datasets. |
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