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| Titel |
A multi-angle aerosol optical depth retrieval algorithm for geostationary satellite data over the United States |
| VerfasserIn |
H. Zhang, A. Lyapustin, Y. Wang, S. Kondragunta, I. Laszlo, P. Ciren, R. M. Hoff |
| 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 ; 11, no. 23 ; Nr. 11, no. 23 (2011-12-02), S.11977-11991 |
| Datensatznummer |
250010232
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| Publikation (Nr.) |
 copernicus.org/acp-11-11977-2011.pdf |
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| Zusammenfassung |
| Aerosol optical depth (AOD) retrievals from geostationary satellites have
high temporal resolution compared to the polar orbiting satellites and thus
enable us to monitor aerosol motion. However, current Geostationary
Operational Environmental Satellites (GOES) have only one visible channel for
retrieving aerosols and hence the retrieval accuracy is lower than those from
the multichannel polar-orbiting satellite instruments such as the Moderate
Resolution Imaging Spectroradiometer (MODIS). The operational GOES AOD
retrieval algorithm (GOES Aerosol/Smoke Product, GASP) uses 28-day composite
images from the visible channel to derive surface reflectance, which can
produce large uncertainties. In this work, we develop a new AOD retrieval
algorithm for the GOES imager by applying a modified Multi-Angle
Implementation of Atmospheric Correction (MAIAC) algorithm. The algorithm
assumes the surface Bidirectional Reflectance Distribution Function (BRDF) in
the channel 1 of GOES is proportional to seasonal average MODIS BRDF in the
2.1 μm channel. The ratios between them are derived through time series
analysis of the GOES visible channel images. The results of AOD and surface
reflectance retrievals are evaluated through comparisons against those from
Aerosol Robotic Network (AERONET), GASP, and MODIS. The AOD retrievals from
the new algorithm demonstrate good agreement with AERONET retrievals at
several sites across the US with correlation coefficients ranges from 0.71 to
0.85 at five out of six sites. At the two western sites Railroad Valley and
UCSB, the MAIAC AOD retrievals have correlations of 0.8 and 0.85 with AERONET
AOD, and are more accurate than GASP retrievals, which have correlations of
0.7 and 0.74 with AERONET AOD. At the three eastern sites, the correlations
with AERONET AOD are from 0.71 to 0.81, comparable to the GASP retrievals. In
the western US where surface reflectance is higher than 0.15, the new
algorithm also produces larger AOD retrieval coverage than both GASP and
MODIS. |
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