Strong-wind events and their influence on the formation of snow dunes: observations from Kohnen station, Dronning Maud Land, Antarctica

• Main Authors: Birnbaum, G., Freitag, J., Brauner, R., König-Langlo, G., Schulz, E., kipfstuhl, J., Oerter, H., Reijmer, C.H., Schlosser, E., Faria, S.H., Ries, H., Loose, B., Herber, A., Duda, M. G., Powers, J. G., Manning, K. W., van den Broeke, M.R.
• Other Authors: Marine and Atmospheric Research, Dep Natuurkunde, Sub Dynamics Meteorology
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2010
• Subjects: Austral; Dronning Maud Land; Kohnen; Kohnen Station; Antarc*; Antarctica; EPICA
• Online Access: https://dspace.library.uu.nl/handle/1874/202998

Analyses of shallow cores obtained at the European Project for Ice Coring in Antarctica (EPICA) drilling site Kohnen station (758000 S, 008040 E; 2892ma.s.l.) on the plateau of Dronning Maud Land reveal the presence of conserved snow dunes in the firn. In situ observations during three dune formation events in the 2005/06 austral summer at Kohnen station show that these periods were characterized by a phase of 2 or 3 days with snowdrift prior to dune formation which only occurred during high wind speeds of >10ms–1 at 2m height caused by the influence of a low-pressure system. The dune surface coverage after a formation event varied between 5% and 15%, with a typical dune size of (4 2)m (8 3) m, a maximum height of 0.2 0.1m and a periodicity length of about 30 m. The mean density within a snow dune varied between 380 and 500 kgm–3, whereas the mean density at the surrounding surface was 330 5kgm–3. The firn cores covering a time-span of 22 2 years reveal that approximately three to eight events per year occurred, during which snow dunes had been formed and were preserved in the firn.