A NASA scientist has developed the first three-dimensional model of snowflake melting that creates a video that is not only beautiful, but can seriously affect weather forecasting and understanding of climate change. Not every snow is the same and scientists have been trying to figure out how to best simulate their melting, as many factors can affect this transition. This new model, described in an article in the Journal of Geophysical Research, has worked it out.
It is the work of Jussi Leinonen, one of NASA's Jet Propulsion Laboratory scientists in Pasadena, California. This may not be an area particularly known for its snowfall, but part of Leinonen's day's work is to identify atmospheric radar profiles taken from the space agency's high-resolution instruments.
These cross sections, which extend from the surface of the planet to the upper atmosphere, still contain some secrets. For example, there is a prominent layer where falling snow and hail melt. "The reasons for this shift are not very clear yet," explains Leinonen, "and there has been some discussion in the community." Of course, this is not the first model of melting snowflakes, but it's one of the deepest yet.
First, the concave areas of the surface of the snowflake serve to collect meltwater; the volume gradually grows until each region comes together. The resulting liquid shell around an ice core eventually develops into a drop of water.
The above video shows the 3D rendering of Leinonen's mathematical model. It shows a snowflake about one centimeter long that consists of several ice crystals that have caught.
While the animation can be beautiful, there is more than just aesthetics to recommend. According to NASA, the model will have practical weather forecasting applications, especially to understand how wet, heavy snow appears on the radar. The distinction of lighter snowfall could make a big difference when it comes to predicting areas threatened by power outages and blocked roads, where power lines and trees can be lowered by the added weight.
In addition, the model could have wider implications for climate change in general. NASA is already monitoring the change of ice sheets, sea ice and snowpacks around the world; mathematical understanding how to apply this to the changes that ice and snow could help predict the evolution of Earth's temperature. Two new satellite missions will be launched later this year to enhance research on the current global ice and snow system.