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| Titel |
A study on the aerosol extinction-to-backscatter ratio with combination of micro-pulse LIDAR and MODIS over Hong Kong |
| VerfasserIn |
Q. S. He, C. C. Li, J. T. Mao, A. K. H. Lau, P. R. Li |
| 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 ; 6, no. 11 ; Nr. 6, no. 11 (2006-08-07), S.3243-3256 |
| Datensatznummer |
250004051
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| Publikation (Nr.) |
 copernicus.org/acp-6-3243-2006.pdf |
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| Zusammenfassung |
| The aerosol extinction-to-backscatter ratio is an important parameter for
inverting LIDAR signals in the LIDAR equation. It is a complicated function
of the aerosol microphysical characteristics. In this paper, a method to
retrieve the column-averaged aerosol extinction-to-backscatter ratio by
constraining the aerosol optical depths (AOD) from a Micro-pulse LIDAR (MPL)
by the AOD measurements from the Moderate Resolution Imaging
Spectroradiometer (MODIS) is presented. Both measurements were taken on
cloud free days between 1 May 2003 and 30 June 2004 over Hong Kong, a
coastal city in south China. Simultaneous measurements of aerosol scattering
coefficients with a forward scattering visibility sensor are compared with
the LIDAR retrieval of aerosol extinction coefficients. The data are then
analyzed to determine seasonal trends of the aetrosol
extinction-to-backscatter ratio. In addition, the relationships between the
extinction-to-backscatter ratio and wind conditions as well as other aerosol
microphysical parameters are presented. The mean aerosol
extinction-to-backscatter ratio for the whole period was found to be
29.1±5.8 sr, with a minimum of 18 sr in July 2003 and a maximum of 44 sr
in March 2004. The ratio is lower in summer because of the dominance of
oceanic aerosols in association with the prevailing southwesterly monsoon.
In contrast, relatively larger ratios are noted in spring and winter because
of the increased impact of local and regional industrial pollutants
associated with the northerly monsoon. The extended LIDAR measurements over
Hong Kong provide not only a more accurate retrieval of aerosol extinction
coefficient profiles, but also significant substantial information for air
pollution and climate studies in the region. |
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