Back in 1856, the American naturalist Henry David Thoreau remarked of snowflakes: “How full of the creative genius is the air in which these are generated! I should hardly admire more if real stars fell and lodged on my coat.”
The six-sided snowflakes described by Thoreau are one of the many shapes that snowflakes can take on, and now a citizen science project called Snowflake ID is using people’s powers of observation to help train a specially designed camera to classify the different types of snowflake that fall.
The aim of the project, run by Tim Garrett and his colleagues at the University of Utah, is not just to catalogue snowflakes, but to use this information to improve weather forecasts. For example, if forecasters know that clouds are amassing small hail-like pellets called graupel, then they can expect a faster accumulation of snow on the ground than if fluffy clusters of traditional snowflakes are gathering.
Such information helps to inform decisions about which roads need to be cleared, or where the avalanche risk is high. Meanwhile, studying the shape, size and density of snowflakes falling to the ground provides information about the type of cloud cover above, enabling scientists to monitor our changing climate.
