No abstract

River discharge is a critical variable in many aspects of hydrology, particularly river mechanics. Due to the importance of river discharge, the standards for performing measurements are already established. In the extreme environmental conditions of breakup in Arctic regions, field crews face significant challenges in carrying out measurements, including risks to personnel, equipment safety, and river access difficulties. The use of a helicopter in performing river discharge measurements with these challenges provides an alternative to using a boat. We present the details of measuring river discharge with the help of a helicopter along the braided Sagavanirktok River on the Alaska North Slope.

Daily average springtime air temperatures from four weather stations distributed along north–south and nearly east–west directions within or on the divide of the Sagavanirktok River watershed in Arctic Alaska were studied and compared with discharge measurements and field observations made from 2015 to 2021 during breakup. The results indicate that under widespread air temperature events, during El Niño, rapid and dynamic breakup can occur (promoting sediment transport along the stream), while during La Niña, slow and thermal breakup can be expected. Due to these climate pattern effects, open channel conditions (i.e., ice-free channels) are reached earlier (18 May 2015) during El Niño and later (7 June 2021) during La Niña.