Surface ablation and its drivers along a west–east transect of the Southern Patagonia Icefield

• Published in: Journal of Glaciology
• Main Authors: Bravo, Claudio, Ross, Andrew N., Quincey, Duncan J., Cisternas, Sebastián, Rivera, Andrés
• Other Authors: Fondo Nacional de Desarrollo Científico y Tecnológico
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2021
• Subjects: Journal of Glaciology
• Online Access: http://dx.doi.org/10.1017/jog.2021.92; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143021000927

Abstract Glaciers in the Southern Patagonia Icefield (SPI) have been shrinking in recent decades, but due to a lack of field observations, understanding of the drivers of ablation is limited. We present a distributed surface energy balance model, forced with meteorological observations from a west–east transect located in the north of the SPI. Between October 2015 and June 2016, humid and warm on-glacier conditions prevailed on the western side compared to dry and cold conditions on the eastern side. Controls of ablation differ along the transect, although at glacier-wide scale sensible heat (mean of 72 W m −2 to the west and 51 W m −2 to the east) and net shortwave radiation (mean of 54 W m −2 to the west and 52 W m −2 to the east) provided the main energy sources. Net longwave radiation was an energy sink, while latent heat was the most spatially variable flux, being an energy sink in the east (−4 W m −2 ) and a source in the west (20 W m −2 ). Ablation was high, but at comparable elevations, it was greater to the west. These results provide new insights into the spatial variability of energy-balance fluxes and their control over the ablation of Patagonian glaciers.