Snow Sublimation in Mountain Environments and Its Sensitivity to Forest Disturbance and Climate Warming. Issue 2 (23rd February 2018)

• Record Type: Journal Article
• Authors: Sexstone, Graham A.; Clow, David W.; Fassnacht, Steven R.; Liston, Glen E.; Hiemstra, Christopher A.; Knowles, John F.; Penn, Colin A.
• Is Part Of: Water resources research. Volume 54:Issue 2(2018)
• Page Start: 1191
• Page End: 1211
• Publication Date: 2018-02-23
• Subjects: sublimation -- SnowModel -- eddy covariance -- Colorado Rocky Mountains -- bark beetles -- climate warming; Hydrology -- Periodicals; 333.91
• DOI: 10.1002/2017WR021172
• Languages: English
• ISSNs: 0043-1397

Abstract

Abstract: Snow sublimation is an important component of the snow mass balance, but the spatial and temporal variability of this process is not well understood in mountain environments. This study combines a process‐based snow model (SnowModel) with eddy covariance (EC) measurements to investigate (1) the spatio‐temporal variability of simulated snow sublimation with respect to station observations, (2) the contribution of snow sublimation to the ablation of the snowpack, and (3) the sensitivity and response of snow sublimation to bark beetle‐induced forest mortality and climate warming across the north‐central Colorado Rocky Mountains. EC‐based observations of snow sublimation compared well with simulated snow sublimation at stations dominated by surface and canopy sublimation, but blowing snow sublimation in alpine areas was not well captured by the EC instrumentation. Water balance calculations provided an important validation of simulated sublimation at the watershed scale. Simulated snow sublimation across the study area was equivalent to 28% of winter precipitation on average, and the highest relative snow sublimation fluxes occurred during the lowest snow years. Snow sublimation from forested areas accounted for the majority of sublimation fluxes, highlighting the importance of canopy and sub‐canopy surface sublimation in this region. Simulations incorporating the effects of tree mortality due to bark‐beetle disturbance resulted in a 4% reduction in snow sublimation from forested areas. Snow sublimation rates corresponding to climate warming simulations remained unchanged or slightly increased, but total sublimation losses decreased by up to 6% because of a reduction in snow covered area and duration. Key Points: Sublimation losses to the atmosphere were equivalent to 28% of winter precipitation and were relatively greater during low snow years Forested areas accounted for the majority of sublimation and bark‐beetle disturbance reduced this flux by 4% The net sublimation flux decreased under warming climate scenarios due to reductions in snow covered area and duration