First results of an inventory of mountain snow information at global scale

Snow information from mountain regions worldwide is of high relevance but its spatial and temporal distribution inhomogeneous. The currently running IACS Joint Body on the Status of Mountain Snow Cover, a joint initiative of IACS together with MRI and WMO GCW aims at improving the snow information, data availability and the access to the data for mountain regions worldwide. As part of the initiative, an inventory was initiated which should provide a first and overall picture on the spatial and temporal availability of snow information in the various mountain regions of the world. As there is no strict delineation of mountain from non-mountain regions, it has been up to the contributing experts to decide on what is part/not part of a mountain region. For larger mountain regions with rather different snow climates, the spatial resolution of the inventory was split into several parts. The inventory was launched in May 2023 and was implemented as on online tool. The paper presents initial analyses of the inventory, looking at the spatial and temporal patterns of snow information at a global scale. The picture derived from the feedback of the inventory shows fairly clear global differences, with regions where individual researchers (e.g. Central Asia) are driving access to snow information, while other regions have well established access routines/portals provided by the institutions operating the snow networks (e.g. the US). A preliminary analysis based on metadata from the inventory, a digital elevation model and the GMBA mountain delineation identifies the distribution of in-situ station and their snow information worldwide and how this varies by region and elevation. Information on already estimated spatial and temporal trends of key snow cover variables from mountain regions, such as for snow depth HS and depth of snowfall HN (from unpublished and published papers), are compiled together, although the different trend periods do not make comparison easy. Overall, a rather inhomogeneous picture emerges with regions such as the Alps or the Scandinavian mountains on the one hand, in which the snow information is spatially and temporally dense (with many published studies), and on the other hand regions (such as Greenland or Patagonia) in which the snow information from observations is extremely sparse.