Towards an operational glacier monitoring service: Europe’s Copernicus Climate Change Service
A Blog post by Isabelle Gärtner-Roer (WDS Scientific Committee member)
In the 'European State of the Climate 2017' report, presented at the European Parliament in April 2018, glaciers represent one-out-of-five 'Headline Climate Indicators', which focus on long-term key indicators for global and regional climate change.
On the global level, the World Glacier Monitoring Service (WGMS; WDS Regular Member) is in charge of compiling changes in glacier length, area, volume, and mass, based on in-situ (length, mass) and remote sensing (area, volume) measurements. An increasing number of glacier-related research projects produce data from air- and space-borne sensors. Combined with the existing in-situ network, these studies complement the multi-level glacier monitoring strategy of the Global Terrestrial Network for Glaciers. WGMS actively fosters glacier observations from space through several initiatives, such as its cooperation with the Copernicus Climate Change Service (C3S) or the Climate Change Initiative of the European Space Agency.
Figure 1. The Copernicus Services implemented by ECMWF
C3S is implemented by the European Centre for Medium-Range Weather Forecasts (ECMWF) within the Copernicus programme, which is Europe’s flagship project to monitor the Earth and her many ecosystems. C3S delivers freely accessible operational data and information services that provide users with reliable and up-to-date information related to environmental issues, and that are based on the Sentinel satellites and other contributing space missions, as well as 'in-situ' (meaning 'in the field' or 'on-site') measurement sensors on land, sea, and air. Collectively, these sources provide huge amounts of Earth observation data that are converted into products for up to 20 Environmental Climate Variables. The products can be freely accessed from a one stop portal: the Copernicus Climate Data Store (CDS). This wealth of climate information forms the basis for generating a wide variety of climate indicators aimed at supporting adaptation and mitigation policies in Europe in a number of sectors; for example, water management, tourism, energy, and health (Fig. 1).
WGMS and the Department of Geography at the University of Zurich, together with Gamma Remote Sensing, the University of Oslo, and the US National Snow and Ice Data Center are contributing glacier data and information to C3S. The partners compile and produce information on the global distribution of glaciers (inventories), as well as their volume and mass changes, using field and remote sensing observations at a global scale. Starting in 2017, they integrated both the Randolph Glacier Inventory 6.0 and the available glacier volume and mass change series from the Fluctuations of Glaciers database maintained by WGMS into the CDS. Furthermore, C3S enables the improvement and extension of existing glacier inventory datasets and will also boost the compilation and computation of glacier volume changes (geodetic method) using space-borne sensors.
Figure 2. Cumulative glacier mass changes in Europe from 1967–2017 for glaciers with long-term records in nine different regions. Cumulative mass balance values are given in the unit ‘metre water equivalent (m w.e.)’ relative to 1997.
Data source: WGMS (2017, updated),.Credit: WGMS / C3S.
Similar to the global mean, glaciers in Europe experienced relative stable to slightly negative mass balances in the 1970s and 1980s with short periods of mass gain (e.g., in the Alps at end of the 1980s or in coastal Scandinavia in the 1990s), followed by strong and continued mass losses after the year 1997 (Fig. 2). Since 1997, the monitored glaciers in Europe have lost between 7 m and 23 m of water equivalent or tons per square metre. In the mean, this is a loss of about 14 tons of water per square metre of ice cover, or when multiplied by the total glacier area (51250 km2, excluding peripheral glaciers on Greenland), about 690 km3; namely, 14-times the water volume of Lake Constance. In other words, the mean annual ice loss of these glaciers (35 km3) would cover the fresh water needs of New York City (see NYC OpenData 2018), the city with the highest consumption worldwide (Kennedy et al. 2015), over a period of about 25 years. The graph also highlights a strong regional variability; in particular, when comparing Northern Scandinavia and the Alps.
– Global Terrestrial Network for Glaciers: http://www.gtn-g.org
– World Glacier Monitoring Service: http://www.wgms.ch
– Copernicus Climate Change Service: https://climate.copernicus.eu/about-c3s
– Earlier WDS Blog post: https://www.icsu-wds.org/news/blog/essential-climate-variables