Blowing Snow Transport Analysis for Estimating Drift Orientation and Severity

Abstract

A methodology for performing a snow drift transport analysis is provided that considers the demonstrated dependency of snow transport on approximately the fourth power of wind speed, giving much greater weight to high winds transporting snow. Data that have long sampling intervals (e.g., 3-h data) do not capture short-duration winds and tend to underpredict snow transport. This study introduces a way to account for the fluctuating component of the wind by including turbulence-intensity estimates. Its use was demonstrated via several cases studies. Based on available data, including turbulence intensity in the transport equations improved the estimate of the snow transport using 3- and 12-h data by 50%–100%. This study also illustrated the error in determining the transport wind direction from a wind rose. In an extreme case, the dominant transport direction was 180° out of phase with the prevailing wind direction determined by wind rose analysis. In two other case studies, a 50°–80° difference between the prevailing wind and dominate snow transport direction was not uncommon.