Snow cover phenology dataset over global mountain regions from 2000 to 2023.

Monitoring temporal and spatial changes in the mountain seasonal snowpack is a key step to better quantify the impact of recent climate warming on this very sensitive environment. In this context, to support the research on large scale, there is an urgent need of consistent and accurate data sets over global mountain regions. This paper presents a dataset derived from Moderate Resolution Imaging Spectroradiometer (MODIS) imagery collection 6.1 onboard of Terra satellite containing information on snow cover area and snow cover phenology (duration, start and end of the season) at 500 m ground resolution and covering the global mountain regions as delineated by the Global Mountain Biodiversity Assessment (GMBA) shapefile. The dataset contains yearly averaged snow cover area (SCA), snow cover duration (SCD), first snow day (FSD) and last snow day (LSD). The snow cover area SCA is based on snow cover fraction daily maps averaged on a yearly basis. To derive the snow phenology variables, SCD, FSD, LSD, a second-order autoregressive approach was adopted to interpolate the data thus reducing the impact of cloud coverage. The dataset was processed for the entire MODIS time series starting from October 2000 up to September 2023 and it is provided on yearly basis considering the hydrological year timeframe: from 1 October to 30 September of the subsequent year for the Northern Hemisphere and from 1 April to 31 March of the subsequent year for the Southern Hemisphere. The use of the data can be manyfold from quantifying the snowpack changes in the last 23 years, to addressing the impact of snowpack changes on water resources and vegetation phenology.