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| Titel |
Understanding the aerosol information content in multi-spectral reflectance measurements using a synergetic retrieval algorithm |
| VerfasserIn |
D. Martynenko, T. Holzer-Popp, H. Elbern, M. Schroedter-Homscheidt |
| 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. 6 ; Nr. 3, no. 6 (2010-11-19), S.1589-1598 |
| Datensatznummer |
250001362
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| Publikation (Nr.) |
 copernicus.org/amt-3-1589-2010.pdf |
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| Zusammenfassung |
An information content analysis for multi-wavelength
SYNergetic AErosol Retrieval algorithm SYNAER was performed to quantify the
number of independent pieces of information that can be retrieved. In
particular, the capability of SYNAER to discern various aerosol types is
assessed. This information content depends on the aerosol optical depth, the
surface albedo spectrum and the observation geometry. The theoretical
analysis is performed for a large number of scenarios with various
geometries and surface albedo spectra for ocean, soil and vegetation. When
the surface albedo spectrum and its accuracy is known under cloud-free
conditions, reflectance measurements used in SYNAER is able to provide for
2–4° of freedom that can be attributed to retrieval parameters:
aerosol optical depth, aerosol type and surface albedo.
The focus of this work is placed on an information content analysis with
emphasis to the aerosol type classification. This analysis is applied to
synthetic reflectance measurements for 40 predefined aerosol mixtures of
different basic components, given by sea salt, mineral dust, biomass burning
and diesel aerosols, water soluble and water insoluble aerosols. The range
of aerosol parameters considered through the 40 mixtures covers the natural
variability of tropospheric aerosols. After the information content analysis
performed in Holzer-Popp et al. (2008) there was a necessity to compare derived degrees of freedom
with retrieved aerosol optical depth for different aerosol types, which is
the main focus of this paper.
The principle component analysis was used to determine the correspondence
between degrees of freedom for signal in the retrieval and derived aerosol
types. The main results of the analysis indicate correspondence between the
major groups of the aerosol types, which are: water soluble aerosol, soot,
mineral dust and sea salt and degrees of freedom in the algorithm and show
the ability of the SYNAER to discern between this aerosol types.
The results of the work will be further used for the development of the
promising methodology of the construction error covariance matrices in the
assimilation system. |
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