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| Titel |
Regional and monthly and clear-sky aerosol direct radiative effect (and forcing) derived from the GlobAEROSOL-AATSR satellite aerosol product |
| VerfasserIn |
G. E. Thomas, N. Chalmers, B. Harris, R. G. Grainger, E. J. Highwood |
| 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. 1 ; Nr. 13, no. 1 (2013-01-15), S.393-410 |
| Datensatznummer |
250017556
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| Publikation (Nr.) |
 copernicus.org/acp-13-393-2013.pdf |
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| Zusammenfassung |
| Using the GlobAEROSOL-AATSR dataset, estimates of the instantaneous,
clear-sky, direct aerosol radiative effect and radiative forcing have
been produced for the year 2006. Aerosol Robotic Network
sun-photometer measurements have been used to characterise the random
and systematic error in the GlobAEROSOL product for 22 regions
covering the globe. Representative aerosol properties for each region
were derived from the results of a wide range of literature
sources and, along with the de-biased GlobAEROSOL AODs, were used to
drive an offline version of the Met Office unified model radiation
scheme. In addition to the mean AOD, best-estimate run of the
radiation scheme, a range of additional calculations were done to
propagate uncertainty estimates in the AOD, optical properties,
surface albedo and errors due to the temporal and spatial averaging of
the AOD fields. This analysis produced monthly, regional estimates of
the clear-sky aerosol radiative effect and its uncertainty, which were combined to
produce annual, global mean values of (−6.7 ± 3.9) W m−2 at the
top of atmosphere (TOA) and (−12 ± 6) W m−2 at the surface. These
results were then used to give estimates of regional, clear-sky
aerosol direct radiative forcing, using modelled pre-industrial AOD
fields for the year 1750 calculated for the AEROCOM PRE experiment. However, as
it was not possible to quantify the uncertainty in the pre-industrial
aerosol loading, these figures can only be taken as indicative and
their uncertainties as lower bounds on the likely errors. Although the
uncertainty on aerosol radiative effect presented here is considerably
larger than most previous estimates, the explicit inclusion of the
major sources of error in the calculations suggest that they are
closer to the true constraint on this figure from similar
methodologies, and point to the need for more, improved estimates of
both global aerosol loading and aerosol optical properties. |
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