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| Titel |
Turbulent structure and scaling of the inertial subrange in a stratocumulus-topped boundary layer observed by a Doppler lidar |
| VerfasserIn |
J. Tonttila, E. J. O'Connor, A. Hellsten, A. Hirsikko, C. O'Dowd, H. Järvinen, P. Räisänen |
| 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 ; 15, no. 10 ; Nr. 15, no. 10 (2015-05-27), S.5873-5885 |
| Datensatznummer |
250119761
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| Publikation (Nr.) |
 copernicus.org/acp-15-5873-2015.pdf |
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| Zusammenfassung |
| The turbulent structure of a stratocumulus-topped marine boundary
layer over a 2-day period is observed with a Doppler lidar at Mace
Head in Ireland. Using profiles of vertical velocity statistics, the
bulk of the mixing is identified as cloud driven. This is supported by
the pertinent feature of negative vertical velocity skewness in the
sub-cloud layer which extends, on occasion, almost to the
surface. Both coupled and decoupled turbulence characteristics are
observed. The length and timescales related to the cloud-driven
mixing are investigated and shown to provide additional
information about the structure and the source of the mixing inside
the boundary layer. They are also shown to place constraints on the
length of the sampling periods used to derive products, such as the
turbulent dissipation rate, from lidar measurements. For this, the
maximum wavelengths that belong to the inertial subrange are studied through
spectral analysis of the vertical velocity.
The maximum wavelength
of the inertial subrange in the cloud-driven layer scales relatively well
with the corresponding layer depth during pronounced decoupled structure
identified from the vertical velocity skewness. However, on many occasions,
combining the analysis of the inertial subrange and vertical velocity
statistics suggests higher decoupling height than expected from the skewness profiles.
Our results show that investigation of the length scales related to the inertial subrange
significantly complements the analysis of the vertical velocity statistics and enables a more
confident interpretation of complex boundary layer structures using measurements from a Doppler lidar. |
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