Pilots generally seek to avoid flying in clouds with “known icing,” but “unknown icing” also lurks out there — that is, our ability to predict and pinpoint which clouds harbor icing conditions is not precise. Now a team of engineers at Rowan University, in New Jersey, is working on a way to enable pilots to detect the threat of icing while en route, in time to change course. The team created ice clouds in a cloud chamber with ice crystals identical to those found in real clouds. They then projected a laser beam through the cloud and measured its change in polarization, which is dependent on the size, shape and distribution of ice crystals. The polarization is invisible to the naked eye, but can be measured using sensitive lenses and photodetectors. Eventually, this process could enable a pilot to use low-power lasers to detect the crystals in time to allow the plane to avoid the crystal-bearing clouds, the researchers say.
“No one has previously done what we are doing in terms of this lab scale and the ability to vary as many elements,” said Todd Nilsen, one of the researchers working on the project. The team, consisting mainly of undergraduates, spent two semesters to build the cloud chamber and develop the research project, funded by a $5,000 grant. The ability to re-create ice crystals that have the same characteristics as those found in nature, on such a small scale, will make it possible to conduct further research with little financial burden.
