Item: AUTOMATED LIDAR REMOTE SENSING FOR MEASURING THE SPATIAL AND TEMPORAL EVOLUTION OF SURFACE HOAR FORMATION
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Title: AUTOMATED LIDAR REMOTE SENSING FOR MEASURING THE SPATIAL AND TEMPORAL EVOLUTION OF SURFACE HOAR FORMATION
Proceedings: International Snow Science Workshop Proceedings 2023, Bend, Oregon
Authors:
- Benjamin Walter [ WSL Institute for Snow and Avalanche Research SLF, CH-7260 Davos Dorf, Switzerland ]
- Loic Brouet [ WSL Institute for Snow and Avalanche Research SLF, CH-7260 Davos Dorf, Switzerland ]
- Matthias Jaggi [ WSL Institute for Snow and Avalanche Research SLF, CH-7260 Davos Dorf, Switzerland ]
- Henning Löwe [ WSL Institute for Snow and Avalanche Research SLF, CH-7260 Davos Dorf, Switzerland ]
Date: 2023-10-08
Abstract: Surface hoar buried within a snowpack by subsequent snowfall forms a weak layer that may fail and result in an avalanche. The spatial variability of surface hoar formation depends on slope aspect, elevation and on local meteorological conditions, making it difficult to predict when and where weak layers form. The aim of this study is to assess the potential of LiDAR remote sensing for the detection and characterization of the spatial and temporal variability of surface hoar. We used an automated laser scanner to periodically scan surface hoar while growing on a snow sample in a ring wind tunnel under laboratory conditions. Our results show that the mean surface reflectance during surface hoar formation may increase or decrease with little changes of ≈ 4%, making it rather useless for surface hoar detection in the field. However, the spatial variability of the reflectance was found to strongly increase up to 600% during surface hoar formation, which is the result of the continuously increasing, plate-like surface hoar crystals of various orientation favouring specular reflections. We propose that the standard deviation of the spatial reflectance variability may be a useful, empirical metric for the detection of surface hoar formation in the field during cold clear nights.
Object ID: ISSW2023_P3.30.pdf
Language of Article: English
Presenter(s): Benjamin Walter
Keywords: surface hoar, lidar, remote sensing, reflectance
Page Number(s): 1409 - 1415
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