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Titel |
Quasi-periodic oscillations of aerosol backscatter profiles and surface meteorological parameters during winter nights over a tropical station |
VerfasserIn |
M. G. Manoj, P. C. S. Devara |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
0992-7689
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Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 29, no. 3 ; Nr. 29, no. 3 (2011-03-04), S.455-465 |
Datensatznummer |
250016985
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Publikation (Nr.) |
copernicus.org/angeo-29-455-2011.pdf |
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Zusammenfassung |
Atmospheric gravity waves, which are a manifestation of
the fluctuations in buoyancy of the air parcels, are well known for their
direct influence on concentration of atmospheric trace gases and aerosols,
and also on oscillations of meteorological variables such as temperature,
wind speed, visibility and so on. The present paper reports quasi-periodic
oscillations in the lidar backscatter signal strength due to aerosol
fluctuations in the nocturnal boundary layer, studied with a high space-time
resolution polarimetric micro pulse lidar and concurrent meteorological
parameters over a tropical station in India. The results of the spectral
analysis of the data, archived on some typical clear-sky conditions during
winter months of 2008 and 2009, exhibit a prominent periodicity of 20–40 min
in lidar-observed aerosol variability and show close association
with those observed in the near-surface temperature and wind at 5%
statistical significance. Moreover, the lidar aerosol backscatter signal
strength variations at different altitudes, which have been generated from
the height-time series of the one-minute interval profiles at 2.4 m vertical
resolution, indicate vertical propagation of these waves, exchanging energy
between lower and higher height levels. Such oscillations are favoured by
the stable atmospheric background condition and peculiar topography of the
experimental site. Accurate representation of these buoyancy waves is
essential in predicting the sporadic fluctuations of weather in the tropics. |
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