Schneefernerhaus as a mountain research station for clouds and turbulence
- 1Max Planck Institute for Dynamics & Self-Organization (MPIDS), 37077 Göttingen, Germany
- 2Leibniz Institute for Tropospheric Research, 04318 Leipzig, Germany
- 3Department of Physics, Michigan Technological University, Houghton, MI 49931, USA
- 4Institute for Nonlinear Dynamics, University of Göttingen, 37077 Göttingen, Germany
- 5Laboratory of Atomic and Solid State Physics and Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY 14853, USA
Abstract. Cloud measurements are usually carried out with airborne campaigns, which are expensive and are limited by temporal duration and weather conditions. Ground-based measurements at high-altitude research stations therefore play a complementary role in cloud study. Using the meteorological data (wind speed, direction, temperature, humidity, visibility, etc.) collected by the German Weather Service (DWD) from 2000 to 2012 and turbulence measurements recorded by multiple ultrasonic sensors (sampled at 10 Hz) in 2010, we show that the Umweltforschungsstation Schneefernerhaus (UFS) located just below the peak of Zugspitze in the German Alps, at a height of 2650 m, is a well-suited station for cloud–turbulence research. The wind at UFS is dominantly in the east–west direction and nearly horizontal. During the summertime (July and August) the UFS is immersed in warm clouds about 25 % of the time. The clouds are either from convection originating in the valley in the east, or associated with synoptic-scale weather systems typically advected from the west. Air turbulence, as measured from the second- and third-order velocity structure functions that exhibit well-developed inertial ranges, possesses Taylor microscale Reynolds numbers up to 104, with the most probable value at ~ 3000. In spite of the complex topography, the turbulence appears to be nearly as isotropic as many laboratory flows when evaluated on the "Lumley triangle".