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| Titel |
Aerosol-cloud interactions in the ECHAM6-HAM2 GCM and Aerosol_cci/Cloud_cci satellite products |
| VerfasserIn |
David Neubauer, Ulrike Lohmann |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250105471
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| Publikation (Nr.) |
 EGU/EGU2015-4997.pdf |
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| Zusammenfassung |
| The first indirect aerosol effect or cloud albedo effect can be estimated as a radiative forcing.
While the sign of this forcing is agreed to be negative, model-based estimates of its
magnitude show a large variability. The responses of cloud liquid water content and cloud
cover to aerosol increases also referred to as secondary indirect aerosol effects or fast
adjustments are uncertain as well. In studies that use the variability in the present day satellite
data to infer aerosol–cloud interactions (ACI), or that constrain model parameterizations
to better agree with satellite observations a less negative ACI radiative forcing is
found.
The projects of the Climate Change Initiative (CCI) programme of ESA aim at producing
long time series of satellite data of essential climate variables with specific information on
errors and uncertainties. The quantification of uncertainty in satellite retrievals provides an
opportunity to get insights in the discrepancy between model based and satellite based
estimates of ACI.
Within the Aerosol_cci project susceptibilities of cloud properties from Cloud_cci to
aerosol properties from Aerosol_cci datasets are to be compared to susceptibilities from the
aerosol climate model ECHAM6-HAM2. Particularly interesting relationships for the first
indirect aerosol effect and the second aerosol indirect effect will be investigated. Satellite
studies show a strong effect of aerosol on cloud amount, which could be a methodological
artefact such as aerosol swelling or meteorological covariation. The immediate
vicinity of clouds needs to be excluded due to these potential cloud contaminations
although it would be the most interesting region for associations between aerosol and
clouds. As the resolution of the data can have an impact on statistical correlations
between cloud and aerosol properties, the assessment will be done on different
scales.
First results will be presented at the conference. |
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