Light Absorbing Particles Are Retained in Snow During Springtime Snowmelt in the Sierra Nevada, CA

Abstract Light absorbing impurities, such as black carbon (BC) and mineral dust (MD) particles, are important constituents of seasonal snowpacks, especially when they are present near the surface where they can influence snow albedo and energy balance. Such impurities can be directly deposited or accumulate on the snow surface during melt processes. While soluble chemical species are known to rapidly flush from snowpacks during melt, the behavior of BC and MD particles, which mostly consist of insoluble species, is not well constrained. Previous work has shown that BC particles can either be concentrated at the snow surface or flushed from the snowpack under different conditions. Here we develop a comprehensive data set of BC and MD particles within and eluting from a seasonal Sierra Nevada, CA, USA snowpack by combining timeseries of snow profile measurements with time‐resolved characterization of meltwater captured by snow lysimeters. Together, the snow and lysimeter measurements indicate that BC and MD particles are retained until the final few days of snowmelt, when they are rapidly flushed from the remaining, shallow snow column. During the final melt, BC and MD concentrations and mass fluxes closely parallel melt rates, indicating that snowpack properties and melt rates are the main controls on how these impurities behave in a given snowpack.