Using Near-Infrared Photography to Better Study Snow Microstructure and Its Variability Over Time and Space

摘要

The methods typically used to study snow stratigraphy, microstructure, and variability are expensive, cumbersome, and often highly subjective. Near-infrared (NIR) photography is a low-cost, portable tool to rapidly collect high-resolution, objective measurements of snow microstructure and variability. To expand its application, an active-source NIR flash was introduced to the traditionally passive-source method. NIR imagery was collected alongside proven snowpit methods such as manual observation, Snow Fork wetness, and Snow Micro-Penetrometer hardness profiles. NIR photography was also deployed in five pits along a 10.6 km transect in Grand Mesa, CO, to track stratigraphy variations in space. The NIR flash was found to improve contrast and lower noise for layer detection using automated statistical processing of the images. NIR photography data complemented traditional methods and was shown to provide unique, insightful observations, especially on stratigraphy and microstructure. NIR photography is demonstrated to be a convenient, valuable method to correlate layer stratigraphy across small and large distances. NIR photography is shown to be a rapid snow stratigraphy technique providing repeatable, unique, and informative insight into the complex and rapidly evolving nature of snowpack stratigraphy, microstructure, and variability.