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| Titel |
Three years of routine Raman lidar measurements of tropospheric aerosols: Backscattering, extinction, and residual layer height |
| VerfasserIn |
J. Schneider, R. Eixmann |
| 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 ; 2, no. 4 ; Nr. 2, no. 4 (2002-11-13), S.313-323 |
| Datensatznummer |
250000631
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| Publikation (Nr.) |
 copernicus.org/acp-2-313-2002.pdf |
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| Zusammenfassung |
| We have performed a three-year series of routine lidar
measurements at preselected times. The measurements were performed between 1 December 1997, and 30 November 2000, at
Kühlungsborn, Germany (54°07' N, 11°46' E). Using a Rayleigh/Mie/Raman lidar
system, we measured the aerosol backscatter coefficients at three wavelengths and the extinction coefficient at one wavelength. The
present data analysis focuses on after-sunset Raman measurements obtained on cloud-free days. Aerosol backscatter profiles are
available for altitudes above 100 m, while the majority of the extinction measurements has been restricted to heights above the
residual layer. The residual layer shows an annual cycle with its maximum height in summer (2000 m) and minimum height in winter
(850 m). The backscatter coefficients in the residual layer were found to be about
10 times higher than above. The mean aerosol optical depth above the residual layer and below
5 km is 0.3(±1.0) x10-2 in summer, and 1.5(±1.0) x10-2 in winter, which almost is negligible
compared to values measured in during daytime in the planetary boundary layer. A cluster analysis of the backward trajectories
yielded two major directions of air mass origin above the residual layer and
4 major directions inside. A marked difference between the aerosol properties dependent on the air mass origin could be
found for air masses originating from the west and travelling at high wind speeds. Comparing the measured spectral dependence of
the backscatter coefficients with data from the Global Aerosol Data Set, we found a general agreement, but only a few conclusions
with respect to the aerosol type could be drawn due to the high variability of the measured backscatter coefficients. |
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