Dynamic of Snow Cover’s Spatial Distribution over Alpine Topography

3D Image of Laser Scanning measurements at the Wannengrat catchment of November 2008 (lower panel) and March 2009 (upper panel). Figure: Luca Egli (SLF/WSL).

The project addresses the description and modeling of the dynamic of snow cover’s spatial distribution over Alpine topography at scales of 1 m, 10 m, 100 m & 1 km – 100 km during accumulation and ablation.

The main objective of the study is the description and modelling of the snow cover's dynamic depending on the underlying topography. Applications of the project are provided for hydrological, snow-climatologic and avalanche dynamic modeling as a subpixel-parametrisation. The main focus of the application is to improve the estimation of Alpine snow water resources stored in form of snow with a stochastic modelling approach. During the ablation period the results of the project help to improve the forecast of meltwater run-off in mountainous rivers.

Steps of the project

• 2008: Dynamics of snow depths variability in the entire Swiss Alpine region: "Hysteretic dynamics of seasonal snow depth distribution in the Swiss Alps", publication in "Geophysical Research Letters" (download).
• November 2008 - Juni 2010: Field season at the Wannengrat test site near Davos using a Terrestrial Laser Scanner (TLS). Biweekly snow depths measurement with a horizontal resolution of 1m and a coverage of alomost 1 km². Main objective of the measurements is to record the seasonal dynamics of snow depths variability on complex Alpine topography during the accumulation and ablation period at scales between 10 m to 1000 m.
  
• April 2009: Analysis of the numerical weather prediction model COSMO-7, in collaboration with MeteoSwiss. COSMO-7 can be used by a simple correction routine to determine daily new snow water equivalent and snow depths on a regular mesh size of 7 km. Publication: "A virtual network for estimating daily new snow water equivalent and snow depths in the Swiss Alps" for "Annals of Glaciology".
• 2010: Hysteresis of the Alpine snow depths variability at scales between 10 km to 100 km. First dataset from the IMIS- and Observer snow measuring network for operational avalanche warning. Second dataset from COSMO-7 weather prediction model (Bachelorthesis Nena Griessinger). Study: "A virtual network for estimating daily new snow water equivalent and snow depths in the Swiss Alps" for "Annals of Glaciology".
• 2010: Hysteretic dynamics of snow depths variability on complex Alpine topography and its influence on the snow water equivalent during the ablation period at the Wannengrat catchment. Study: „Dynamics of snow ablation in a small Alpine catchment observed by terrestrial laser scans”.
• 2011: First simple stochastic model approach based on the observed dynamic of the seasonal development of snow depth variability with verification in the Dischma-Valley (Davos) .
• Outlook: The stochastic model will be combined with latest technologies (e.g. optical scanner) to estimate the variability of snow depths and to improve the prediction of meltwater forecast.

Project team

• Luca Egli
• Tobias Jonas

Students / trainees

Nena Griessinger (2009)

Contact