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Titel |
The effect of the global UV irradiance measurement accuracy on the single scattering albedo retrieval |
VerfasserIn |
S. Kazadzis, J. Gröbner, A. Arola, V. Amiridis |
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 ; 3, no. 4 ; Nr. 3, no. 4 (2010-08-12), S.1029-1037 |
Datensatznummer |
250001217
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Publikation (Nr.) |
copernicus.org/amt-3-1029-2010.pdf |
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Zusammenfassung |
The possibility of measuring aerosol optical absorption properties in the UV
spectral range such as single scattering albedo (SSA), using remote sensing
techniques, is currently an open scientific issue. We investigate the
limitations on calculating column average SSA using a combination of global
UV spectral measurements (that are comon in various UV monitoring stations
worldwide) with radiative transfer modeling. To point out the
difficulties in such a retrieval we have used the travelling reference
spectroradiometer QASUME (Quality Assurance of Spectral Ultraviolet
Measurements in Europe) results from 27 visits to UV monitoring stations
around Europe.
We have used the QASUME instrument as relative reference, analyzing
absolute differences and also temporal and spectral deviations of UV
irraidances, that are used as basic input for the SSA retrieval.
The results comparing the mean SSA derived by all instruments, measuring
synchronous UV spectra, showed that 5 were within ± 0.02 difference from
the SSA calculated from the QASUME instrument, while 17 were within ± 0.04, for the Solar zenith angle of 60 degrees. As for the uncertainty that
has been calculated using the 2σ standard deviation of the spectral
measurements, a mean 0.072 and 0.10 (2σ) uncertainties have been
calculated for 60° and 30°, respectively. Based on the fact that
additional uncertainties would be introduced in the SSA retrieval from AOD
model input accuracy, assymetry parameter assumptions, we show that only
very few instrumnents could be able to detect long term SSA changes.
However, such measurements/results ar useful in order to retrieve SSA at UV
wavelengths, a product needed for various applications such as, inputs for
modeling radiative forcing studies and satellite retrieval algorithms. |
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