Snow research – from roads to snowball fights

Snow is not just something we pulse through in winter – it is a complex material that affects everything from traffic to tire development and the perfect shape of the snowball. Johan Casselgren and his team of researchers are working to understand snow in depth, partly to improve road safety. But he can also explain to us why some types of snow are better than others for snowball fights.

Snow and traffic - data that saves lives

Through collaborations with the Swedish Transport Administration and their suppliers Volvo Cars and Nira Dynamics, researchers at Luleå University of Technology analyze how snow affects road friction. Connected cars and plow trucks collect huge amounts of data - as many as 45 million friction measurements per month – which are then processed with advanced algorithms.

"Sometimes one driving lane can be slippery while the other has better traction. By interpreting data from plough trucks, their position, speed and salt and ploughing efforts, we can optimize winter road maintenance," says Johan Casselgren, assistant professor and researcher in experimental mechanics with a focus on snow and ice.

The tire industry is also using this research. Winter tire tests show that results can differ depending on where they are conducted - Nokian tires performed best in Ivalo, while Pirelli's were better in Älvsbyn. The reason? Snow differs between locations, and to get fair results you need to understand its characteristics.

How to create the perfect snowball?

The same snow properties that affect the grip of your tires also determine whether you can make a perfect snowball.

"It's all about the shape of the snow grains and how much moisture the snow contains. When the snow has just fallen, the grains are often star-shaped, but over time they transform into small round balls – a process called metamorphism. For a snowball to stick together, it needs a certain amount of moisture and the right temperature, preferably close to zero degrees," says Casselgren.

Is it too cold? Then you need to compress the snow harder. Is it warm? Then the moisture helps the grains to freeze together so that the snow almost becomes ice. So the history of snow affects how it behaves – an insight that can both settle a snowball fight and improve winter tire testing.

The magic of snow - benefit and pleasure

Research is not only about improving road safety, but also about understanding the unique properties of snow.

"I'm totally buried in this, Casselgren says with a laugh. It's so much fun to share – snow is a part of our everyday lives, but few people realize how much it actually affects us."

Next time you're standing there with a snowball in your hand – remember that it's a result of temperature, moisture and the history of snow grains. And if you're taking part in the World Snowball Fighting Championship? Then you can be sure that the snow is perfect for the battle, created using a tent and a diesel generator to create the best snow for the task.