Heat balance of a low-elevated Svalbard glacier during the ablation season: A case study of Aldegondabreen

Abstract

ABSTRACT On the basis of in situ weather observations and a physical-based model, verified by a glaciological method, this article investigates the surface energy balance of the Aldegondabreen glacier during the summer melt season of 2021. Aldegondabreen (5.3 km2) is a low-elevation glacier near the western shore of Spitsbergen Island. On the timescale of the whole melt season, the prevalent positive heat flux is a shortwave radiative balance (84 percent). This result is in accordance with previous studies on similar low-elevation Svalbard glaciers. However, in August and September, when the sun is low, the turbulent fluxes may outweigh the input of the shortwave balance. The study identified six events of significantly increased turbulent fluxes, which contributed to 10 percent of the total heat influx, and attributed them to the particular type of synoptic situation. All of these events are related to cyclonic activity, which drastically increased the wind speed in the study area and, consequently, both sensible and latent heat fluxes. The frequency of the extreme cyclonic events in the Svalbard region is increasing, which may potentially extend the duration of the glacier melt season in the mid- and late autumn or reduce the accumulation of solid precipitation in that time period.