Satellites make ski treks safer

Satellites make ski treks safer

September 30, 2013
Senior Research Scientist

Tromsø scientists want to establish a centre of excellence for avalanche monitoring.

By using satellites and unmanned aerial vehicles (UAV) we will be able to measure snow everywhere, and in addition we will be able to provide better warning of avalanches, snow melting, floods and climate changes. Tromsø scientists wish to establish a centre of excellence for avalanche monitoring.

In the winter of 2013 there was a series of large avalanches in Troms, which led to closed roads for weeks, evacuated communities and the loss of six lives. Half of all the avalanches resulting in fatalities in Norway over the past decade have occurred in the Tromsø area. The large increase in summit ski climbs is an important cause of the many avalanche accidents.

The avalanches in 2013 were triggered after prolonged periods of snowfall on unstable layers of snow caused by mild weather and rain in late February. The snow avalanche danger scale remained at considerable throughout the entire period.

The avalanche forecasts are published on the website varsom.no. These forecasts are based on weather forecasts and knowledge about the snow conditions in the mountains. Wind direction, temperature, unstable layers of snow and a host of other factors come into play. The Norwegian Water Resources and Energy Directorate (NVE) and the Norwegian Meteorological Institute collaborate to prepare the forecasts.

Avalanche observers

In order to remedy the lack of observations, NVE has employed several avalanche observers to undertake measurements in the mountains. This activity involves 1-2 people in the Tromsø area. Even though this is a significant improvement compared to earlier, we realize that it will be difficult for a couple of people to monitor the varying conditions we have in the mountains.

During the spring Norut worked to test out the use of radar satellites and UAV for monitoring avalanches. Up to now this research has had two objectives.

Firstly, we want to be able to detect avalanches that have been triggered. We were able to demonstrate this well through both high resolution radar satellite images and UAV on Senja and at Kattfjordeidet in March and April.

Secondly, we want to be able to measure the properties of the snow, such as depth, layering and moisture, which may be important for avalanche warning. We can now use radar satellites to measure moisture in snow. Using satellite, we observed that the snow had been wet high up in the mountains in late February. This layer of wet snow would later prove to be a major factor for the high avalanche activity.

The results of this research must be regarded as extremely promising, and could in time be included in the avalanche warning. The results will be presented at avalanche and satellite conferences during the autumn.

Satellites and unmanned aerial vehicles

At the same time we notice that satellites have certain limitations. Current satellites do not enable us to measure important properties such as depth and layering.

Consequently, we wish to use UAV with radars that penetrate the snow and measure depth and various layers. Cameras that characterize the surface of the snow will also be able to provide detailed information in avalanche areas. At the same time we will be able to test out technology that may come in the satellites of the future.

Norut in collaboration with the Norwegian Geotechnical Institute (NGI) have therefore this autumn applied for a major research project, in which we propose to develop a centre of excellence for avalanche monitoring based on satellite and UAV technology. Our ambition is for this centre to become a world leader in this type of monitoring.

We believe that a new centre of excellence for monitoring of avalanches will provide the basis for improved avalanche warning and enhanced knowledge of where and when avalanches are triggered. Last winter we also observed avalanches from satellites that had not been reported previously, as they occurred in areas where few people venture. Archived satellite images can also show what the snow was like before the avalanches.

The scientists in Tromsø are already world leading in the use of satellites for monitoring snow. These maps are used, for instance, by the power companies to calculate the amount of snow in their reservoirs. Other users of satellite-based snow maps include scientists, meteorologists, hydrologists responsible for flood preparedness and ecologists in nature resource management.

Can measure everywhere

Norut has collaborated with Kongsberg Satellite Services (KSAT) since the 1990s on the use of various satellite sensors for mapping snow. The images from different satellites are currently processed automatically at KSAT. The snow maps are supplied to a host of users, both nationally and internationally.

The advantage of satellites is that they make it possible to obtain measurements everywhere. Such data serves as a valuable supplement to the more detailed ground surveys at a few places in the mountains or at the meteorological stations.

We currently monitor Norway, Sweden and Finland on a daily basis. The maps will soon be expanded to cover the whole of Europe. Through an EU-financed project, Norut and KSAT are currently collaborating with scientists from Finland, Switzerland and Austria to supply snow maps for the whole of Europe.

Tromsø leading the way

The EU will also launch a series of new satellites from 2014. These satellites will allow us to monitor the whole world frequently and with images of extremely good quality. For Norwegian conditions, the Sentinel 1 satellites are of particular importance.

The first of these satellites will be launched in March 2014 and will feature a radar with particularly impressive characteristics. It will be able to provide daily monitoring of the High North in great detail, regardless of the weather and light conditions. This will represent a big step forward for the snow and avalanche applications.

Monitoring of snow is important both locally and globally. The research and technology community in Tromsø is an international leader in this area, and is now concentrating on building a centre in Tromsø that will be responsible for monitoring areas that pose a danger for avalanches. This is important in order to plan safer ski treks, monitor our energy resources and study changes in the snow owing to climate changes.

We believe that a new centre of excellence for avalanche monitoring will provide the basis for improved avalanche warning and enhanced knowledge of where and when avalanches are triggered.

This chronicle was published in Nordlys on September 27 in conjunction with the annual Norwegian Science Week.