 |
| Titel |
Rocket measurements of positive ions during polar mesosphere winter echo conditions |
| VerfasserIn |
A. Brattli, T. A. Blix, Ø. Lie-Svendsen, U.-P. Hoppe, F.-J. Lübken, M. Rapp, W. Singer, R. Latteck, M. Friedrich |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1680-7316
|
| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 6, no. 12 ; Nr. 6, no. 12 (2006-12-07), S.5515-5524 |
| Datensatznummer |
250004200
|
| Publikation (Nr.) |
 copernicus.org/acp-6-5515-2006.pdf |
|
|
|
|
|
| Zusammenfassung |
| On 18 January 2005, two small, instrumented rockets were launched
from Andøya Rocket Range (69.3° N, 16° E) during
conditions with Polar Mesosphere Winter Echoes (PMWE). Each of the
rockets was equipped with a Positive Ion Probe (PIP) and a Faraday
rotation/differential absorption experiment, and was launched as
part of a salvo of meteorological rockets measuring temperature and
wind using falling spheres and chaff. Layers of PMWE were detected
between 55 and 77 km by the 53.5 MHz ALWIN radar. The rockets were
launched during a solar proton event, and measured extremely high
ion densities, of order 1010 m−3, in the region where PMWE
were observed. The density measurements were analyzed with the
wavelet transform technique. At large length scales, ~103 m,
the power spectral density can be fitted with a k−3 wave number
dependence, consistent with saturated gravity waves.
Outside the PMWE layers the k−3 spectrum extends down to
approximately 102 m where the fluctuations are quickly damped and
disappear into the instrumental noise. Inside the PMWE layers the
spectrum at smaller length scales is well fitted with a k−5/3
dependence over two decades of scales. The PMWE are therefore
clearly indicative of turbulence, and the data are consistent with
the turbulent dissipation of breaking gravity waves. We estimate a
lower limit for the turbulent energy dissipation rate of about
10−2 W/kg in the upper (72 km) layer. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|