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| Titel |
Deriving the effect of wind speed on clean marine aerosol optical properties using the A-Train satellites |
| VerfasserIn |
V. P. Kiliyanpilakkil, N. Meskhidze |
| 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. 22 ; Nr. 11, no. 22 (2011-11-16), S.11401-11413 |
| Datensatznummer |
250010194
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| Publikation (Nr.) |
 copernicus.org/acp-11-11401-2011.pdf |
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| Zusammenfassung |
| The relationship between "clean marine" aerosol optical properties and
ocean surface wind speed is explored using remotely sensed data from the
Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on board the
CALIPSO satellite and the Advanced Microwave Scanning Radiometer (AMSR-E) on
board the AQUA satellite. Detailed data analyses are carried out over 15
regions selected to be representative of different areas of the global ocean
for the time period from June 2006 to April 2011. Based on remotely sensed
optical properties the CALIPSO algorithm is capable of discriminating
"clean marine" aerosols from other types often present over the ocean
(such as urban/industrial pollution, desert dust and biomass burning). The
global mean optical depth of "clean marine" aerosol at 532 nm
(AOD532) is found to be 0.052 ± 0.038 (mean plus or minus standard
deviation). The mean layer integrated particulate depolarization ratio of
marine aerosols is 0.02 ± 0.016. Integrated attenuated backscatter and
color ratio of marine aerosols at 532 nm were found to be 0.003 ± 0.002 sr−1
and 0.530 ± 0.149, respectively. A logistic regression
between AOD532 and 10-m surface wind speed (U10) revealed three
distinct regimes. For U10 ≤ 4 m s−1 the mean CALIPSO-derived
AOD532 is found to be 0.02 ± 0.003 with little dependency on the
surface wind speed. For 4 < U10 ≤ 12 m s−1, representing the
dominant fraction of all available data, marine aerosol optical depth is
linearly correlated with the surface wind speed values, with a slope of
0.006 s m−1. In this intermediate wind speed region, the AOD532
vs. U10 regression slope derived here is comparable to previously
reported values. At very high wind speed values (U10 > 18 m s−1),
the AOD532-wind speed relationship showed a tendency toward leveling
off, asymptotically approaching value of 0.15. The conclusions of this study
regarding the aerosol extinction vs. wind speed relationship may have been
influenced by the constant lidar ratio used for CALIPSO-derived AOD532.
Nevertheless, active satellite sensor used in this study that allows
separation of maritime wind induced component of AOD from the total AOD over
the ocean could lead to improvements in optical properties of sea spray
aerosols and their production mechanisms. |
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