Heat balance of supraglacial lakes in the western Dronning Maud Land

• Published in: Annals of Glaciology
• Main Authors: Matti Leppäranta, Elisa Lindgren, Lauri Arvola
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press 2016
• Subjects: Antarctic glaciology; blue ice; heat balance; mass balance; radiation transfer; sublimation; Meteorology. Climatology; QC851-999; Antarctic; Dronning Maud Land; Annals of Glaciology; Antarc*
• Online Access: https://doi.org/10.1017/aog.2016.12; https://doaj.org/article/6ce04482ca0c44e883b6b64688d8bd54

Thermodynamics of a seasonal supraglacial lake were examined based on field data from three summers. At maximum, the lake body consisted of an upper layer with thin ice on top, and a lower layer with slush, hard ice and sediment at the bottom. Sublimation from the upper ice surface averaged to 0.7 mm d−1, and melting in the ice interior averaged to 9.1 mm d−1 during summer. Albedo was on average 0.6 and light attenuation coefficient was ~1 m−1. Averaged over December and January, and over 3 different years, we found that the net solar heating was 137 W m−2, while the losses averaged to 62 W m−2 for the longwave radiation, 16 W m−2 for the sensible heat flux, 24 W m−2 for the latent heat flux and 3 W m−2 for the bottom flux. The depth scale is determined by the light attenuation distance and thermal diffusion coefficient, and the net liquid water volume ranged from 0.5 to 1.0 m in different years. The potential winter growth is more than summer melting, and thus the lake freezes up completely in winter in the present climate.