Climate controls on snow reliability in French Alps ski resorts

Abstract

Ski tourism is a major sector of mountain regions economy, which is under the threat of long-term climate change. Snow management, and in particular grooming and artificial snowmaking, has become a routine component of ski resort operations, holding potential for counteracting the detrimental effect of natural snow decline. However, conventional snowmaking can only operate under specific meteorological conditions. Whether snowmaking is a relevant adaptation measure under future climate change is a widely debated issue in mountainous regions, with major implications on the supply side of this tourism industry. This often lacks comprehensive scientific studies for informing public and private decisions in this sector. Here we show how climate change influences the operating conditions of one of the main ski tourism markets worldwide, the French Alps. Our study addresses snow reliability in 129 ski resorts in the French Alps in the 21st century, using a dedicated snowpack model explicitly accounting for grooming and snowmaking driven by a large ensemble of adjusted and downscaled regional climate projections, and using a geospatial model of ski resorts organization. A 45% snowmaking fractional coverage, representative of the infrastructures in the early 2020s, is projected to improve snow reliability over grooming-only snow conditions, both during the reference period 1986–2005 and below 2 °C global warming since pre-industrial. Beyond 3 °C of global warming, with 45% snowmaking coverage, snow conditions would become frequently unreliable and induce higher water requirements.

Overloaded! Critical revision and a new conceptual approach for snow indicators in ski tourism

“…Nevertheless, in situ time series have long been used for the assessment of both snow and climatic conditions at the local and regional scales. Beyond the use of in situ data for the calculation of indicators for each location, in situ *Depending on the specific snow model setting, "technical" may refer to "natural but groomed," "natural and machine-made," and "natural, machinemade, and groomed" snow data can be interpolated or extrapolated in space, in order to generate driving data for snowpack models spanning a wider range of locations within and around ski areas (e.g., Hanzer et al 2014) and compute spatially distributed indicator values for entire ski areas (e.g., François et al 2014;Spandre et al 2019a). In contrast, mountain areas are generally inadequately represented in large-scale climate datasets, both due to a lack of some of the key processes in mountain regions in the models and to their too coarse spatial resolution (Hock et al 2020).…”

Snow Reliability and Water Availability for Snowmaking in the Ski resorts of the Isère Département (French Alps), Under Current and Future Climate Conditions

“…Snow conditions in each of the ski resorts were simulated using the SURFEX/ISBA-Crocus model (Brun et al, 1992;Vionnet et al, 2012) with recent developments referred to as Crocus-Resort allowing explicit consideration of snowmaking and grooming (Spandre et al, 2016(Spandre et al, , 2019. In French mountain areas, Crocus is generally driven by meteorological data provided by the SAFRAN system (Durand et al, 1993).…”

“…In order to feed the Crocus-Resort model and the hydrological models, the hourly meteorological time series over the period 1950-2100 were calculated using the ADAMONT method developed by Verfaillie et al 2017, using the SAFRAN reanalysis as an observation base for the period 1960-1990. In order to cover the uncertainties associated with possible climate changes in the coming decades, thirteen distinct climate scenarios were used, each composed of global model driving a regional model (see Verfaillie et al, 2018 andSpandre et al, 2019, for the list of models used).…”

Fiabilité de l’enneigement et disponibilité des ressources en eau pour la production de neige dans les domaines skiables du Département de l’Isère (France), en conditions climatiques actuelles et futures

“…Ces échanges ont également permis la collecte de données complémentaires (consommation et approvisionnement en eau, pilotage des installations et fréquentation) nécessaires pour contextualiser notre approche et ainsi comparer les valeurs issues des simulations avec celles mesurées. Les conditions d'enneigement sur chacun des domaines skiables ont été modélisées en utilisant le modèle SURFEX/ISBA-Crocus (Brun et al, 1992 ;Vionnet et al, 2012) avec les récents développements baptisés Crocus-Resort permettant la prise en compte explicite de la production de neige et du damage (Spandre et al, 2016, Spandre et al, 2019. Dans les zones de montagnes françaises, Crocus est généralement utilisé en association avec le Système d'Analyse Fournissant des Renseignements Atmosphériques à la Neige (SAFRAN) (Durand et al, 1993).…”

“…Afin d'alimenter le modèle Crocus-Resort et le modèles hydrologiques, les chroniques météorologiques horaires sur la période 1950-2100, spatialisées sur les massifs, ont été calculées grâce à la méthode ADAMONT développée par Verfaillie et al (2017), en utilisant la réanalyse SAFRAN comme base d'observation pour la période 1960-1990. Afin de couvrir les incertitudes associées aux évolutions possibles du climat dans les décennies à venir, nous avons utilisé treize scénarios climatiques distincts, composés chacun du couple d'un modèle global avec un modèle régional(voir Verfaillie et al, 2018et Spandre et al, 2019, pour la liste des modèles utilisés).…”