Pflug et al. (2024) -- Processed data and model outputs

Snow distribution at wind-drift spatial scales ( 10 m) can be difficult to estimate due to modeling and observational constraints. Fortunately, the timing of snow disappearance is related to the distribution of snow water equivalent (SWE) throughout the spring snowmelt season. Here, we show that snow cover maps generated from PlanetScope’s constellation of Dove Satellites can resolve the 3 m date of snow disappearance across seven alpine domains in California and Colorado. Across a 5-year period (2019 – 2023), the average uncertainty in the date of snow disappearance, or the period of time between the last date of observed snow cover and first date of observed snow absence, was 3 days. Using a simple shortwave-based snowmelt model calibrated at nearby snow pillows, the PlanetScope date of snow disappearance could be used to reconstruct spring snow water equivalent (SWE). Relative to lidar SWE estimates, the SWE reconstruction had a spatial coefficient of correlation of 0.75, and SWE spatial variability that was biased by 9%, on average. SWE reconstruction biases were then improved to within 0.04 m, on average, by adjusting snowmelt rates using assumed distributions of SWE spatial heterogeneity and the evolution of fractional snow cover observed by PlanetScope. This study demonstrates the utility of fine-scale and high-frequency optical observations of snow cover, and the simple and annually repeatable connections between snow cover and spring snow water resources in regions with seasonal snowpack.