Tackling the Difficult Problem of Predicting Snowfall Accumulation
Most of us enjoy watching a gentle winter snowfall settle over the landscape. We might, perhaps, enjoy wondering if it will grant us a “snow day,” a break from work or school. However, when we see snow piling up quickly driven by high winds, our wondering might take on more urgency. Even after many years of study, predicting snow accumulation is a very difficult problem.
Authors Michele Guala (University of Minnesota Department of Civil, Environmental, and Geo-Engineering and the St. Anthony Falls Laboratory) and Jiarong Hong (University of Minnesota Department of Mechanical Engineering and the St. Anthony Falls Laboratory) have been working together in the area of snow imaging and settling for the last 10 years.
Recently, they wrote a review of the careful observations, experimentations, and future prediction models that snow scientists have developed over the last 80 years. Their review was recently published in the Annual Review of Fluid Mechanics. A review of this scope is a great effort, and also an honor.
Guala described how they came to write this review.
“Usually, the editorial board of Annual Reviews selects scientists who have been working steadily in a specific field of fluid mechanics. They approached me, triggered by the work Jiarong Hong and I did on turbine wakes, near surface turbulence, and snow settling, asking if we were interested in writing a review paper. I suggested a few topics and they liked the idea of snow settling in turbulence, which has never been reviewed.
“The same privilege was once given to my Ph.D. advisors, Giovanni Seminara and Ronald J. Adrian. It happens once in a lifetime, when it happens. So, I feel this is a great honor, and frankly, a very hard task. It took most of my energy for more than one year.
“The goal of this article is to recognize the complexity of snow particles falling in a turbulent atmosphere, to define the parameter space required to investigate the settling velocity more rigorously than what has been done in the past, and ultimately to set the experimental requirement to tackle this problem in future investigations. It is a very difficult problem, and despite the recent advances, we are still far from providing a complete modeling framework. That is one reason, among other challenges, snow accumulation is so hard to forecast.”
Guala noted, “Our department (CEGE) maintains a prestigious legacy with the Annual Review of Fluid Mechanics. To the best of my knowledge, it started with Roger Arndt, and continued with Fotis Sotiropoulos, Emmanuel Detourney, Kimberly Hill. So, stay tuned for the next one from CEGE!”