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| Titel |
Aerosol single scattering albedo retrieved from ground-based measurements in the UV and visible region |
| VerfasserIn |
V. Buchard, C. Brogniez, F. Auriol, B. Bonnel |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 4, no. 1 ; Nr. 4, no. 1 (2011-01-03), S.1-7 |
| Datensatznummer |
250001563
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| Publikation (Nr.) |
 copernicus.org/amt-4-1-2011.pdf |
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| Zusammenfassung |
Estimates of Aerosol Single Scattering Albedo (SSA) from ground-based
spectral measurements in the UV-visible are conducted at Villeneuve d'Ascq
(VdA) in France. In order to estimate this parameter, measurements of global
and diffuse UV-visible solar irradiances performed under cloud-free
conditions since 2003 with a spectroradiometer operated by the Laboratoire
d'Optique Atmosphérique (LOA) are used. The technique consists in
comparing the measured irradiance values to modelled irradiances computed
for various SSA. The retrieval is restricted to the 330–450 nm range to
avoid ozone influence.
For validation purpose, the retrieved values of SSA at 440 nm are compared
to the ones obtained from sunphotometer measurements of the AERONET/PHOTONS
network available on the LOA site. The results are rather satisfying: for
the period 2003–2006 the Root Mean Square (RMS) of the differences is about
0.05, this value is within the uncertainty domain of retrieval of both
products. Distinction between days characterized by different aerosol
content, by means of the aerosol optical thickness (AOT) retrieved from
ground-based measurements at the same wavelength, shows that the comparisons
between both products are better when AOT are higher. Indeed in case AOT are
greater than 0.2, the RMS is 0.031 compared to 0.060 for days with an AOT
lower than 0.2. The SSA estimated at 340 and 380 nm from ground-based
spectra are also studied, though no validation can be carried out with
sunphotometer data (440 nm is the shortest wavelength at which the SSA is
provided by the network). The good comparisons observed at 440 nm can let
assume that the SSA retrieved from spectroradiometer measurements at the two
other wavelengths are also obtained with a good confidence level. Thus these
values in the UV range can be used to complete aerosol data provided by
AERONET/PHOTONS at VdA. Moreover they can be used for a best knowledge of
the aerosol absorption that is necessary to quantify the error on surface UV
irradiances estimated from satellites. |
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