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| Titel |
Summertime shallow katabatic flows in Dronning Maud Land, Antarctica |
| VerfasserIn |
Rostislav Kouznetsov, Priit Tisler, Timo Palo, Timo Vihma |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250082185
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| Zusammenfassung |
| The vertical structure of the atmospheric boundary layer had been observed near the Finnish
Antarctic station Aboa in Dronning Maud Land (73°03’S, 13°25’W) in austral
summer 2010-2011 by means of the three-axes Doppler sodar Latan-3 and a 10-m
meteorological mast. The measuring site is located at practically flat slightly sloped (about
1%) surface of the glacier. The sodar was operated with 20–800Â meters sounding
range, 20 m vertical and 10 s temporal resolution. The mast was equipped with wind
and temperature measurements at 5 levels and two sonic anemometers at 2 and 10
meters.
During the measurements the atmospheric boundary layer was most of the time within the
sounding range of the sodar. A large variety of sodar echo patterns and wind speed profiles
have been observed, however, several cases of clear steady katabatic flows were observed.
Practically all of them were Easterly, whereas the uphill direction is Southern. The thickness
of the katabatic flow varied from few tens to several hundreds of meters, the wind speed
maximum could be as low as 5Â meters. Thin katabatic flows had lower wind speed and much
stronger temperature gradient (up to 1Â K/m), but smaller surface heat flux than the thicker
ones.
Such situations pose a major challenge for meteorological models, since the surface layer
in these cases appears just within the lowest meters. |
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