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| Titel |
Large mesospheric ice particles at exceptionally high altitudes |
| VerfasserIn |
L. Megner, M. Khaplanov, G. Baumgarten, J. Gumbel, J. Stegman, B. Strelnikov, S. Robertson |
| 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 ; 27, no. 3 ; Nr. 27, no. 3 (2009-03-02), S.943-951 |
| Datensatznummer |
250016429
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| Publikation (Nr.) |
 copernicus.org/angeo-27-943-2009.pdf |
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| Zusammenfassung |
| We here report on the characteristics of exceptionally high Noctilucent clouds
(NLC) that were detected with
rocket photometers during the ECOMA/MASS campaign at Andøya, Norway 2007.
The results from three separate flights are shown
and discussed in connection to
lidar measurements.
Both the lidar measurements and the large difference
between various rocket passages through the NLC show that the cloud
layer was inhomogeneous on large scales. Two passages showed a
particularly high, bright and vertically extended cloud, reaching to approximately
88 km.
Long time series of
lidar measurements show that NLC this
high are very rare, only one NLC measurement out of
thousand reaches above 87 km.
The NLC is found to consist of three distinct layers.
All three were bright enough to
allow for particle size retrieval by phase function analysis, even though the
lowest layer proved too
horizontally inhomogeneous to obtain a trustworthy result. Large particles,
corresponding to an effective radius of 50 nm, were observed both in the
middle and top of the NLC.
The present cloud does not comply with the conventional picture that
NLC ice particles
nucleate near the temperature minimum and grow to larger sizes as they sediment to lower
altitudes. Strong
up-welling, likely caused by gravity wave activity, is required to explain its
characteristics. |
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