Snow Water Equivalent Measurements in Remote Arctic Alaska Watersheds

Snow surveys in two Arctic watersheds located in Alaska, USA, provide 32 years of spatially distributed snow water equivalent (SWE) and snow depth observations. Annual snow surveys from the Imnavait Creek (20,036 measurements from 1985 to 2017) and Upper Kuparuk River (5,804 measurements from 1997 to 2017) watersheds were conducted to capture end-of-winter snow accumulation. The average end-of-winter SWE in the Upper Kuparuk River watershed (102 29 mm) is consistently less than the Imnavait Creek watershed (130 34 mm) during the common period of record (1997-2017). The average end-of-winter SWE in both watersheds indicates a positive trend. Comparison of SWE records with cumulative solid precipitation measured at the Imnaviat [sic] SNOTEL site highlights the undercatch of gauge precipitation and difference in long-term trends. In this paper, we present a historic overview of data collection, discuss data accuracy, and point out advantages and limitations associated with ground-based snow measurements in remote Arctic locations. As new methods and techniques of measuring SWE and solid precipitation become available, the presented data set will provide a historic perspective for new observations and will quantitatively relate current or future snow conditions to those that have occurred since the late twentieth century. Key Points Repeated snow surveys (25,840 measurements over 32 years) are conducted in two Arctic watersheds for hydrologic applications Annual snow water equivalent range is 73-207 mm, with average SWE of 124 +/- 34 mm in the Imnavait Creek watershed (1985-2017) Annual snow water equivalent range is 51-169 mm with average SWE of 102 +/- 29 mm in the Upper Kuparuk River watershed (1997-2017)