Arctic Alaska has been warming at a rate two times greater than the global average. The timing and magnitude of snowmelt runoff is impacted by this warming and changes in precipitation, permafrost, and snow cover. Snowmelt spring floods are the largest hydrologic event of the year in many Arctic Alaska river systems.
Research focused on hydrology in the Upper Kuparuk River watershed, where long-term air temperature, precipitation, and streamflow measurements were used to provide exploratory statistical analysis and hydrologic modeling.
While no statistically significant trends in snow accumulation and snowmelt runoff were identified during 1993-2017, observations highlight large year-to-year variability and include extreme years. Snow water equivalent ranges from 5.4 to 17.6 cm (average 11.0 cm) , peak snowmelt runoff ranges from 3.84 to 50.0 cms (average 22.4 cms) and snowmelt peak occurrence date ranges from May 13 to June 5 for the Upper Kuparuk period of record. The spring of 2015 stands out as the warmest, snowiest year on record in the Upper Kuparuk.
Further investigation into snowmelt included the analysis of remote sensing snow data and application of the Snowmelt Runoff Model (SRM). The MODIS snow product MODSCAG was successfully used to create accurate snow depletion curves for the Upper Kuparuk and improve hydrologic modeling using SRM. Testing SRM in the Upper Kuparuk provided insights and a set of recommendations for improved snowmelt runoff forecasting and hydrologic modeling in Arctic Alaska.
