QUANTIFYING TOPOGRAPHIC CONTROLS OF SNOWPACK MASS AND ENERGY BALANCES FOLLOWING HIGH-ELEVATION WILDFIRE IN THE SOUTHERN ROCKY MOUNTAINS

Wildfires are impacting high-elevation seasonal snowpacks at significantly greater rates since 2000. This increase in wildfire introduces considerable water resource management challenges as wildfires significantly alter the accumulation of snow and the timing and rate of snowmelt for at least a decade post-fire. While a consensus of the impacts of wildfire on seasonal snowpacks has emerged, there remains a key knowledge gap in how these impacts are modulated by complex terrain that typically characterize mountain environments. At high-elevations in the 2020 Cameron Peak wildfire burned area, there was no significant difference in peak snow water equivalent between burned and unburned areas on both north and south aspects in the second winter post-fire. Burned south aspects reached peak snow water equivalent 22-days prior to burned north and all unburned areas. Burned south aspects lost snow water equivalent at 147% of unburned south aspects (7.7–19.0 mm d^-1). Ablation rates on burned north aspects were elevated by 61% compared to unburned similar aspects (11.9–19.2 mm d^-1). These differences in ablation rates were driven by energy balance discrepancies with the net radiation flux being more positive at the burned site than the unburned site over the entire study period. These differences were due to a 137% increase in cumulative net radiation at the burned site unburned site while longwave radiation decreased by 206% at the burned site. We found snow processes on south aspects are more altered following wildfire than similar burn conditions on north aspects, resulting in earlier peak SWE date, rapid SWE ablation, and earlier SDD.