The role of surface storage in a low-gradient Arctic watershed

[1] The Arctic land surface water balance plays an important role in regulating the planetary heat balance and global ocean circulation. Lakes and wetlands are common features in the low-gradient Putuligayuk River watershed in northern Alaska, with important implications for the annual water balance. Evapotranspiration exceeds precipitation over the summer, and there is a gradual reduction in wetland extent. Total inundated area derived from RADARSAT ScanSAR synthetic aperture radar images throughout 1999 and 2000 varied from 15 to 67 percent of the 471 km(2) watershed. The hydrological system becomes disconnected within 2 weeks of snowmelt, and overland flow largely ceases. End-of-winter snow water equivalent and discharge during the melt period for 1999, 2000, and 2001 were used to estimate that between 30 and 37 mm (24-42 percent) of snow meltwater serves to recharge the evaporation deficit of the previous summer. The percent of snowmelt entering storage is dependent on the available surface storage.