New satellite technology has been tested in the Schnalstal/Sinalis Valley to measure the thermal conductivity of snow

Over the past few days, a small Cessna carrying experimental technology has flown over the Senalis Valley in South Tyrol between Lake Fernago and Grawand. Over the course of two flights, a sensor measured the heat exchange between the snow and the air.

On the ground, along the same roads, eight teams led by Eurac Research experts measured the depth of the snow with stepped rails and the weight of the snow to determine its type. If analysis of the data collected proves that the technology is reliable and the measurements match those taken on the ground, it can be superimposed on satellites.

For weeks, emails between researchers have been circulating: “There is a possible window next week,” “Cancelled: bad weather on the way,” “We will try again once high pressure returns.” Then finally the announcement: “We have to move on for tomorrow.” Emails take on a new tone. Equipment checklists, updated equipment checklists, flight plans, and safety arrangements for the umpteenth time.

At first light on April 4, the first group sets out, loaded with skis, ski skins, and backpacks. Soon after, a small Cessna took off from Trento Airport. On board, the technology will be tested.

The first flight reached the valley around 7 am, and the second around 1 pm. During each flight, the Cessna zigzagged over the area at 5,000 meters for about 40 minutes. For the research team, getting the same flight at different times of the day was crucial.

“So far, to monitor snow, we’ve used satellite imagery that measures direct characteristics such as depth and density,” explains Carlo Marin, remote sensing engineer at Eurac Research.

“Instead, this technology developed by the University of Milano Bicocca measures how snow respires, that is, the heat exchange between snow and air. From this information we can measure properties such as the density and type of snow. On an early morning ride, the temperature is colder, and in the warmer hours From today, the surface layer of snow is much warmer due to higher temperatures and sunlight. The difference in temperature relates to how different types of snow exchange heat with their surroundings.”

“In addition, the sensor’s experimental images are very high resolution.”

As the small Cessna flew along 12 sectors technically known as “cross sections,” 22 people were on the ground measuring the depth and weight of the snow at three-meter intervals. By doing so, we were able to determine the density of the snow: the heavier the moisture, the lighter, powderier and finer it was.

Some search parties were not far from the lifts, but others had to reach remote areas, such as the summit of Teufelsegg, below Weisskugel / Palla Bianca (3738m), by trekking for hours with skis, skiskins and backpacks loaded with equipment. One team was also accompanied by technicians carrying the same type of sensors that were installed on board to further confirm the measurements from the ground.

In the coming months, the research team will review the measurement results and test whether the technology is mature enough to be installed on a satellite and put into operation.

“In light of the climate crisis making water an increasingly scarce and valuable commodity, an accurate account of the presence of snow, particularly at high altitudes, will become increasingly important in assessing more accurately the availability of water for the summer season and, thus, providing support to those who must Manage this resource,” Marin concludes.