In order to be able to study glaciers, snow and permafrost worldwide better, researchers have formed networks and linked monitoring stations.
It’s actually quite simple: to measure the snow depth, you push a measuring rod into the snow cover until it reaches the ground and then note the value. That’s all. But what do you do if the snow is lying on a glacier or on sea-ice where there is no ground? Similar questions arise with almost all the variables that snow researchers record, regardless of whether they are measuring density, grain shape or temperature. Scientists tend to use different measurement methods, which is why their data are often not comparable.
Researchers from very different countries therefore created the network Global Cryosphere Watch (GCW) under the umbrella of the World Meteorological Organisation. A GCW working group certifies monitoring stations and sites that collect and store cryosphere data according to established standards or standards developed by GCW. The cryosphere refers to all parts of the Earth in which snow falls or lies, where rivers, lakes or seas are frozen seasonally or throughout the year, and where permafrost, glaciers or ice sheets can be found. This applies to around hundred countries worldwide at all latitudes.
Reliable and professionally performed measurements are essential for ensuring information about snow and ice from all over the world can be used – which is GCW’s main aim. What may sound rather dry can actually have considerable impact. For example, snow-depth measurements from the Caucasus were previously not available, but they will be soon – thanks to the GCW. This will make it easier to understand how climate change is affecting seasonal snow cover worldwide.
Charles Fierz at SLF is a member of GCW’s steering committee. He sees the group’s work extending beyond science: “In some regions in the world with ongoing political conflicts, snow and glacier measurements enable initial rapprochements between the people,” he explains, citing Russia and Georgia as examples where scientists from two hostile countries are working together.
Using data better instead of just collecting more
In Switzerland, such political tensions are fortunately not a problem. The country can therefore set an example with the way it documents and carefully keeps long-term datasets. Charles worked hard to ensure that a whole cluster of monitoring stations in the region Davos were included in the GCW network. “This means the value of our work can be better appreciated worldwide because we don’t necessarily need to collect more data, but we should use it better,” he explains. Wolfgang Schöner, from the University of Graz, who is responsible for the certification of the monitoring stations in GCW, sees this similarly: “The Davos cluster is internationally an outstanding example. Not only do the stations monitor the permafrost, snow and glaciers and record any changes, but they also note how they interrelate with climate change.”
To be able to use such valuable data and experiences in other parts of the world, data-exchange between researchers must function as simply as possible. Charles and his colleagues at SLF are therefore elaborating standard processes, defining data formats and developing software further for all the researchers in the GCW network to use so that they can record their data in a comparable way and exchange it among themselves. “This is of particular benefit for researchers from countries where the economic conditions do not allow them to finance such tools themselves,” says Wolfgang.
And what about measuring snow depths on glaciers or sea-ice now? “That’s simple,” says Charles: “A reference depth must first be set. Where possible, this is the ground, but if it’s on ice, it must be defined. It could, for example, be the snow surface on 31 December of the previous year. What exactly is defined as the reference depth is not really relevant – it must just be well documented and always applied in the same way.” (Birgit Ottmer, Diagonal 2/18)