Scaling properties of snow depth over larger domains: Is there a second scale break?

The scaling properties of snow depth provide valuable information to understand snow dynamics in Alpine areas. Previous studies have reported detailed observational datasets and insights on the main drivers of snowpack distribution in different regions of the world through variogram analysis, identifying scale break lengths and their anisotropies. The identification of such breaks helps to determine the combination of processes that govern snow dynamics at different spatial scales, providing guidance for the spatial configuration of physically based snow and hydrological models. Nonetheless, most of the domains previously studied are not large enough to identify potential large scale break lengths, as the observations usually relied on Terrestrial Laser Scanners. This study exploits a dataset of more than 20 UAV (Unmanned Aerial Vehicles) observations covering more than 300 ha at the Izas Experimental Catchment and the surrounding area (located in Central Spanish Pyrenees) from 2020 to 2023. The extent of this novel observational technique has enabled variogram analysis up to 2000 m, along with the adjustment of other geostatistical models (multisegment log-log linear, speherical, Gaussian and exponential). The results obtained in this study area, show a very high temporal consistency for the first detected scale break lengths and a variety of second scale break lengths. The dominant wind direction and the topographic characteristics observed in this study area might partially explain the snowpack scaling properties. These results are compared with previous snow depth variogram analyses conducted on TLS (Terrestrial Laser Scanner) observations for a smaller area in the same study site.
The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)