 |
| Titel |
Comparing turbulent parameters obtained from LITOS and radiosonde measurements |
| VerfasserIn |
A. Schneider, M. Gerding, F.-J. Lübken |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 4 ; Nr. 15, no. 4 (2015-02-27), S.2159-2166 |
| Datensatznummer |
250119465
|
| Publikation (Nr.) |
 copernicus.org/acp-15-2159-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| Stratospheric turbulence is important for the mixing of trace species and the
energy balance, but direct measurements are sparse due to the required
resolution and accuracy. Recently, turbulence parameters such as the energy
dissipation rate ε were inferred from standard radiosonde data by
means of a Thorpe analysis. To this end, layers with vertically decreasing
potential temperature are analysed, which is expected to indicate turbulence.
Such an application assumes a proportionality between the Thorpe length
LT and the Ozmidov scale LO. While this relation is
accepted for the ocean, experimental evidence for such proportionality in the
stratosphere is sparse. We have developed a high-resolution (8 kHz)
turbulence measurement system called LITOS (Leibniz Institute Turbulence
Observations in the Stratosphere), which for the first time resolves the inner
scale of turbulence in the stratosphere. Therewith the energy dissipation rate
ε can be determined by spectral analysis. This independent value for
ε enables us to check the relation LO ∝ LT.
In our measurements no such proportionality can be seen, although the mean of
the ratio LO/LT is close to what is assumed in radiosonde
analyses. Dissipation rates for individual layers obtained from radiosondes
deviate up to a factor of ~3000 from those obtained by spectral analysis.
Some turbulent layers measured by LITOS are not observed by the radiosonde at all,
and vice versa.
However, statements about the statistical mean seem to be possible by Thorpe analysis. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|