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Titel |
Influence of scintillation on quality of ozone monitoring by GOMOS |
VerfasserIn |
V. F. Sofieva, V. Kan, F. Dalaudier, E. Kyrölä, J. Tamminen, J.-L. Bertaux, A. Hauchecorne, D. Fussen, F. Vanhellemont |
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 ; 9, no. 23 ; Nr. 9, no. 23 (2009-12-07), S.9197-9207 |
Datensatznummer |
250007786
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Publikation (Nr.) |
copernicus.org/acp-9-9197-2009.pdf |
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Zusammenfassung |
Stellar light passing through the Earth atmosphere is affected by refractive
effects, which should be taken into account in retrievals from stellar
occultation measurements. Scintillation caused by air density irregularities
is a nuisance for retrievals of atmospheric composition. In this paper, we
consider the influence of scintillation on stellar occultation measurements
and on the quality of ozone retrievals from these measurements, based on
experience of the GOMOS (Global Ozone Monitoring by Occultation of Stars)
instrument on board the Envisat satellite.
In GOMOS retrievals, the scintillation effect is corrected using
scintillation measurements by the fast photometer. We present quantitative
estimates of the current scintillation correction quality and of the impact
of scintillation on ozone retrievals by GOMOS. The analysis has shown that
the present scintillation correction efficiently removes the distortion of
transmission spectra caused by scintillations, which are generated by
anisotropic irregularities of air density. The impact of errors of dilution
and anisotropic scintillation correction on the quality of ozone retrievals
is negligible. However, the current scintillation correction is not able to
remove the wavelength-dependent distortion of transmission spectra caused by
isotropic scintillations, which can be present in off-orbital-plane
occultations. This distortion may result in ozone retrieval errors of
0.5–1.5% at altitudes 20–40 km. This contribution constitutes a
significant percentage of the total error for bright stars. The advanced
inversion methods that can minimize the influence of scintillation
correction error are also discussed. |
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