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Titel |
Continuous monitoring of the boundary-layer top with lidar |
VerfasserIn |
H. Baars, A. Ansmann, R. Engelmann, D. Althausen |
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 ; 8, no. 23 ; Nr. 8, no. 23 (2008-12-10), S.7281-7296 |
Datensatznummer |
250006497
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Publikation (Nr.) |
copernicus.org/acp-8-7281-2008.pdf |
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Zusammenfassung |
Continuous lidar observations of the top height of the boundary
layer (BL top) have been performed at Leipzig (51.3° N,
12.4° E), Germany, since August 2005. The results of
measurements taken with a compact, automated Raman lidar over a
one–year period (February 2006 to January 2007) are presented.
Main goals of the study are (a) to demonstrate that BL top
monitoring with lidar throughout the year is possible, (b) to
present the required data analysis method that permits an
automated, robust retrieval of BL top at all weather situations,
and (c) to use this opportunity to compare the lidar-derived BL
top data with respective BL tops hourly predicted by the regional
weather forecast model COSMO. Four different lidar methods for the
determination of the BL top are discussed. The wavelet covariance
algorithm is modified so that an automated retrieval of BL depths
from lidar data is possible. Three case studies of
simultaneous observations with the Raman lidar, a vertical-wind
Doppler lidar, and accompanying radiosonde profiling of
temperature and humidity are presented to compare the potential
and the limits of the four lidar techniques. The statistical analysis of the one-year data
set reveals that the seasonal mean of the daytime (about
08:00–20:00 Local Time, LT) maximum BL top is 1400 m in spring,
1800 m in summer, 1200 m in autumn, and 800 m in winter at the
continental, central European site.
BL top typically increases by 100–300 m per hour in
the morning of convective days. The comparison between the
lidar-derived BL top heights and the predictions of COSMO yields
a general underestimation of the BL top by about 20% by the
model. |
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