Field-based investigation of snow-drift flux increases in blowing snow and application to mapping of short-term visibility reduction using mesoscale meteorological simulation

Blowing snow, driven by strong winds, significantly reduces visibility and poses a serious threat to winter road safety in snowy regions. To address this issue, this study aimed to investigate the short-term fluctuations in snow-drift flux caused by turbulent wind gusts, which can lead to rapid visibility reductions. We conducted field observations in a snowfield located on the east side of Hokkaido, Japan, to analyze the relationships between 10-min mean wind speed, 10-min mean snow-drift flux, and the maximum 1-min mean snow-drift flux during the same period. Using these relationships, we demonstrated visibility maps with mesoscale meteorological simulation as an application. Our results indicated that the 10-min mean snow-drift flux at 1.0 m height under a wind speed of 20 m/s was two orders of magnitude larger than that at a wind speed of 10 m/s. Additionally, the maximum 1-min snow-drift flux was approximately three times larger than the 10-min mean value. Thus, the estimated minimum 1-min mean visibility showed approximately half of the 10-min mean visibility. These findings provide valuable insights into the spatial distribution of visibility reduction, which could be instrumental in improving road safety measures and guiding drivers to select appropriate routes during blowing snow conditions.