Field research of diamond dust in Fairbanks, Alaska

Project Report Overseas Fellowship Program Report

January 23, 2025

Overseas Fellowship Program Participant：FY2024 Short-Term Program
Satoko Oki (University of Toyama)

For about three weeks from November 14 to December 10, 2024, I stayed in Fairbanks, Alaska, to conduct field observations of diamond dust. Diamond dust is generally considered to be a phenomenon in which small snow crystals (ice crystals) sparkle on a clear, windless winter day. However, the actual conditions under which diamond dust is observed are unclear. On the other hand, the Arctic region is known as one of the places on earth where climate change is most pronounced. In order to investigate how diamond dust, a phenomenon that occurs at low temperatures, is currently occurring in such a place, I visited Fairbanks, Alaska, near the Arctic Circle. Specifically, a time-lapse camera was set up on the campus of the University of Alaska Fairbanks, and when diamond dust was generated, observations were made using a digital microscope in addition to video and photography (Fig. 1). A thermo-hygrometer was also installed on the university campus to record weather data from the surrounding area.

(Fig. 1) Taking close-up photographs using a digital microscope

During our stay, we were able to observe diamond dust only once, on November 27 (Fig. 2). Along with diamond dust, a rainbow (sundog), which can be seen in the direction of the sun under very cold conditions, was also observed on that occasion. On November 27 and 28, we also succeeded in taking close-up photographs of ice crystals drifting in the air (Fig. 3). We plan to organize the occurrence of ice crystals based on observation records and further analysis using remote sensing data.

(Fig. 2) Diamond dust observed during the stay

The average temperature in Fairbanks in winter is -15°C. It was very difficult for us to get used to the cold. At its lowest point, the temperature was -36°C, and we had to deal with many equipment malfunctions due to the cold. On the other hand, I was able to see the Northern Lights (Fig. 4), which can only be seen in the polar regions, and participate in Thanksgiving, an American holiday, which made my days very fulfilling in terms of both research and daily life.