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| Titel |
On the efficient treatment of temperature profiles for the estimation of atmospheric transmittance under scattering conditions |
| VerfasserIn |
R. Lindstrot, R. Preusker |
| 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 ; 5, no. 10 ; Nr. 5, no. 10 (2012-10-26), S.2525-2535 |
| Datensatznummer |
250003131
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| Publikation (Nr.) |
 copernicus.org/amt-5-2525-2012.pdf |
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| Zusammenfassung |
| The vertical temperature profile of the atmosphere has an influence on the
width and intensity of gaseous absorption lines. In the visible and near
infrared part of the spectrum, this poses a problem for the fast forward
simulation of the radiative transfer, needed in algorithms for the retrieval
of any atmospheric or surface-related parameter from satellite measurements.
We show that the main part of the global variability of temperature profiles
can be described by their first 2 to 6 eigenvectors, depending on the
accuracy requirement, by performing a Principal Component Analysis (PCA) on a
global set of temperature profiles from the Global Forecast System (GFS).
Furthermore, we demonstrate the possibility to approximate the atmospheric
transmittance in the O2 A band for any temperature profile with almost
perfect accuracy by a linear combination of the transmittances attributed to
each of the significant temperature eigenvectors. For the retrieval of
surface pressure from O2 A band measurements, this reduces the global root
mean square error from >30 hPa to better than 1 hPa by strongly reducing
the regional bias of surface pressure, retrieved on the assumption of an
average temperature profile. The technique can be applied under scattering
conditions to eliminate temperature-induced errors in, e.g., simulated
radiances. In principal, the method can be useful for any problem including
gaseous absorption or emission with a significant influence of the
temperature profile, such as the retrieval of total water vapour content
or sea surface temperature. |
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