OBSERVER: Managing winter’s challenges with Copernicus Land
OBSERVER: Managing winter’s challenges with Copernicus Land
evan
Fri, 13/12/2024 – 11:53
As winter approaches, the Northern Hemisphere faces growing challenges linked to climate change, with unpredictable snowfall patterns and shorter snow seasons impacting ecosystems, water resources, and industries. These shifts underscore the importance of tools like the Copernicus Land Monitoring Service (CLMS), which provides critical data on snow and ice coverage to support decision-making in hydropower generation, flood prevention, and ecological conservation.
In today’s Observer, we explore how CLMS snow products are helping Europe adapt to a warming climate and manage the complex challenges of winter.
A changing winter landscape
As winter descends on the Northern Hemisphere, Europe braces for yet another unpredictable snow season. With the continued warming of the global climate, snowfall and snow accumulation trends are undergoing a dramatic shift away from their stable and predictable past towards an increasingly volatile and uncertain future.
Lower elevation areas, particularly in southern Europe and the lower Alps, now experience significantly reduced snowfall as warmer temperatures bring rain instead. Snow seasons across the continent are becoming shorter as well, disrupting ecosystems, straining water resources, and threatening winter sports industries which rely on steady snow cover. The quality of the snow is also changing, with denser, wetter snow becoming more common, a phenomenon with significant consequences when snow begins to melt. Meanwhile, snowfall remains more consistent at higher elevations and in some cases has actually intensified due to increased atmospheric moisture.
This volatility not only complicates life for communities and industries tied to winter weather, it also puts undue pressure on ecosystems and species adapted to snowy winters. With Europe’s winter climate becoming more unpredictable, the future of snow cover is uncertain and will likely continue to shift as warming progresses. It is therefore more important than ever to have tools at our disposal to help us monitor and adapt to these changing conditions.
A suite of datasets for monitoring snow and ice coverage
The Copernicus Land Monitoring Service (CLMS) provides a suite of datasets related to mapping and monitoring of snow and ice coverage, which provides useful insights into snow dynamics. These datasets, derived from spatial observations at varying resolutions, are mostly delivered in near real-time. Broadly, CLMS snow products fall into three main categories: Snow Cover Extent, Snow State, and Snow Water Equivalent.
The Snow Cover Extent products provide daily and yearly updates on snow cover in Europe and the Northern Hemisphere:
- Northern Hemisphere (1 km resolution, daily): Covers land areas between 25°N and 84°N latitude, including Greenland but excluding mountainous regions.
- Continental Europe (500 m resolution, daily): Extends from 35°N to 72°N latitude and 11°W to 50°E longitude, encompassing forested and non-forested areas.
- Pan-European Fractional Snow Cover (20 m resolution, daily): Provides detailed daily updates for the land areas of EEA38 and the UK, distinguishing snow cover on the canopy and ground.
- Persistent Snow Area (20 m resolution, yearly): Derived from Fractional Snow Cover data, this product provides annual maps showing the extent of persistent snow cover for the land areas of EEA38 and the UK.
Products in the Snow State category provide information on the relative wetness of snow and snow condition across Europe:
- SAR Wet Snow: Targets high-mountain areas within the land areas of EEA38 and the UK, providing data on wet snow extent and distinguishing snow-free, patchy, or dry snow areas.
- Wet/Dry Snow: Covers the land areas of EEA38 and the UK, identifying snow-free regions and distinguishing between wet and dry snow conditions.
Both SAR Wet Snow and Wet/Dry Snow products are based on Sentinel-1 radar data at 60 m resolution.
Finally, the Snow Water Equivalent product provides estimates of the amount of liquid water stored in the snowpack for land surface areas in the Northern Hemisphere between 35°N and 85°N latitude. Its coverage excludes equatorial regions, subtropical zones, the Arctic areas beyond 85°N, as well as mountainous regions, glaciers, and Greenland.
Supporting hydropower generation through better understanding of snowmelt dynamics
The CLMS snow products are not only important for understanding snow and ice dynamics but also play a critical role in supporting industries which depend on snowmelt as a resource. In Alpine nations such as Austria and Switzerland, over 60% of energy production comes from hydroelectric power, making it arguably the region’s most crucial energy source. This energy is largely harnessed through large dams, which act as the primary infrastructure for capturing the energy of water. These dams store massive volumes of water in reservoirs, which can be released to drive turbines and produce electricity. Although rain and groundwater help to replenish these reservoirs, the primary source is snowmelt. Snow accumulates through the winter and then melts as temperatures rise in the spring. This water then flows into rivers and streams that feed into hydroelectric reservoirs. Sudden or intense melting events can strain dam infrastructure and pose safety concerns, while insufficient melt can reduce electricity generation, impacting the energy supply for communities and industries. For this reason, accurate melt pattern predictions are essential for managing reservoirs effectively and maximising electricity output.
Predictive models are, however, very reliant on high quality, accurate data. Fortunately, CLMS’s Wet/Dry Snow product provides users with near-real-time information on the wet snow extent and the snow-free, patchy, or dry snow extent across the European continent. Like all CLMS datasets, it is also freely available to the public. This combination of quality and accessibility has led to eager uptake by users, including regional authorities such as the Environmental Protection Agency of Aosta Valley in the Italian Alps, which leverages these wet snow data to create models which can be used, among other things, for optimising hydropower generation in the region.
Managing the risks of spring thaw and flooding
The spring thaw presents other challenges beyond hydroelectric power generation. Dammed reservoirs allow for more control over the flow of water, but the vast majority of water bodies do not have such infrastructure in place. This means that snowmelt typically enters streams and rivers in an uncontrolled manner, which can, and regularly does, cause significant flooding in downstream areas. The likelihood of these kinds of flooding events is exacerbated during years of above-average snowfall or during periods of rapid warming, both of which are becoming more common as the climate patterns continue to shift. As such, having the ability to monitor both the total snow cover and the relative water content of the snowpack is crucial for regional authorities in their emergency planning and disaster prevention efforts.
In June of this year, melting snow and heavy rains caused massive flooding of the Vénéon River in the French Alps. The floods were catastrophic, all but destroying the village of La Bérarde. CLMS snow products proved invaluable in analysing the role of snowmelt in the disaster, leveraging Sentinel-2 satellite imagery which showed a significant reduction in snowpack, and then using snow maps to quantify this change. This provided important insights into snow cover extent before and after the flood. By combining these data with Copernicus Climate Change Service (C3S) ERA5 climate datasets, researchers determined that rain fell at high altitudes, destabilising an already water-saturated snowpack and accelerating snowmelt. This kind of information is invaluable for understanding the factors which contribute to such disasters, enabling authorities to refine their risk assessments and update predictive models, ensuring better preparation and more effective mitigation strategies for future flood events.
Supporting alpine ecology with CLMS data
CLMS Water, Snow & Ice data products are also invaluable in the field of alpine ecology. With climate change drastically altering snow cover patterns and shortening snow seasons, alpine habitats are facing unprecedented challenges. As an example, ecologists studying the white-winged snowfinch—a bird uniquely adapted to snowy, high-altitude environments—used Fractional Snow Cover datasets to remotely monitor snow patterns, revealing that these birds preferentially nest in areas with above-average snow cover. This nesting behaviour is tightly linked to their reliance on crane fly larvae, which flourish in the wet soils near melting snowpack. As snowfall decreases and snowmelt timing shifts, these changes threaten the snowfinch’s ability to find suitable nesting sites and feed its offspring, highlighting the broader ecological challenges facing alpine species in a warming climate. The implications of this study extend beyond the snowfinch. This methodology can be applied to monitor the behavior, physiology, and habitats of other at-risk alpine species, from birds to mammals and insects, whose survival is intricately linked to snow cover.
A critical tool for adapting to the complex challenges of winter
CLMS is an essential resource for facing the challenges of winter under climate change. From supporting hydropower generation in Alpine nations to helping predict spring flooding, CLMS snow and water products enable stakeholders to anticipate challenges and develop effective mitigation strategies. In the realm of alpine ecology, these datasets empower researchers to study the intricate relationships between snow cover and species survival, offering hope for conservation in the face of climate change.
As climate impacts intensify, the need for reliable, actionable data has never been greater. The quality and reliability of CLMS’s data products promises to improve our understanding of snow and ice dynamics for years and perhaps even decades to come. By equipping decision-makers with the tools necessary to adapt to an uncertain future, CLMS stands as a cornerstone of Europe’s commitment to environmental stewardship and sustainable development.
Fri, 13/12/2024 – 12:00
