Insights into the North Hemisphere daily snowpack at high resolution from the new Crocus-ERA5 product

Abstract. This article provides a detailed analysis of the Crocus-ERA5 snow product covering the Northern Hemisphere from 1950 to 2022. It assesses the product’s performance in terms of snow depth and extent compared to in situ observations and satellite data. Compared to its predecessor, Crocus-ERA-Interim, Crocus-ERA5 benefits from improved spatial resolution and better atmospheric data assimilation, resulting in more accurate snowpack estimates, especially in spring in Eurasia. The findings show a good match with observations, though biases remain, particularly in boreal forest areas and some Arctic regions, where the model tends to overestimate spring melt. The production of this snow dataset is motivated by its use by the continental cryosphere community, and in particular by the collaboration between the French National Center for Meteorological Research (CNRM) and Environment and Climate Change Canada (ECCC), which has been involved in Arctic snow cover monitoring as part of the "Terrestrial Snow" section of the Arctic Report Card since 2017. The Crocus-ERA5 product is freely available on a daily basis and at 0.25° resolution over the 1950-07-01 to 2023-06-30 period (Decharme et al., 2024, https://doi.org/10.5281/zenodo.14513248).