Parameters determining water temperature of a proglacial stream: The Phelan Creek and the Gulkana Glacier, Alaska

Abstract

AbstractThe heat budget of a proglacial stream, Phelan Creek, from the Gulkana Glacier, Alaska, is estimated by using the hourly time series of stream water temperature, discharge and meteorology obtained in the summer of 2006. As an analytical result, the net shortwave radiation and bed friction occupied 32.1 and 38.2% of the total thermal input to the stream, respectively. The time series of the water temperature were simulated by a deterministic model with the coupling of the heat budget and the thermal advective diffusion equation. The simulated result is agreeable to the observed one with the Nash‐Sutcliffe efficiency (NASH) of 0.747 and the root‐mean‐square error (RMSE) of 0.236°C over the observation period. However, under condition that the rainfall of more than 1 mm h−1 occurs continually for more than a day, the simulation was less reasonable with NASH = 0.225 and RMSE = 0.226°C. This is probably because the relatively warm subsurface flow input to the stream channel from the non‐glacial area. Copyright © 2009 John Wiley & Sons, Ltd.