Item: Deriving Mean Snow Depth in Complex Terrain From Flat Field Measurements
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Title: Deriving Mean Snow Depth in Complex Terrain From Flat Field Measurements
Proceedings: International Snow Science Workshop 2016 Proceedings, Breckenridge, CO, USA
Authors:
- Nora Helbig [ SLF, Davos Dorf, Switzerland ]
- Alec van Herwijnen [ SLF, Davos Dorf, Switzerland ]
- Tobias Jonas [ SLF, Davos Dorf, Switzerland ]
Date: 2016-10-02
Abstract: Snow depth is an important parameter for various applications, including hydrological and avalanche forecasting. Various measurement networks were therefore developed throughout the world to measure snow depth and/or snow water equivalent. However, measurement stations are generally located in gentle terrain (flat field measurements) most often at lower or mid elevation. While measurements from these sites have provided a wealth of information, various studies have questioned the representativity of such flat field snow depth measurements for the surrounding topography, especially in alpine regions. In this study, we used highly resolved snow depth maps at peak of winter from two distinct climatic regions in eastern Switzerland and in the Spanish Pyrenees to develop a mean snow depth parameterization for large-scale model applications over complex topography based on flat field snow depth measurements and easy to derive topographical parameters. Removing the elevation dependent gradient in mean snow depth revealed remaining topographic correlations with the sky view factor. We performed a scale dependent analysis for domain sizes to specify error statistics inherent in large-scale grid cell sizes. Overall, our results show that correlations between subgrid terrain characteristics and mean snow depth increase with increasing domain size. As the parameterization is independent of a specific geographic region it could be used to assimilate flat field snow depth measurements into large-scale snow model frameworks.
Object ID: ISSW16_P1.46.pdf
Language of Article: English
Presenter(s):
Keywords: mean snow depth, avalanche forecasting, meteorological models, subgrid parameterization
Page Number(s): 707-712
Subjects: avalanche forecasting weather models snow depth
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