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

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.

Automated summary

Research on the Southern Patagonia Icefield suggests that glacial ablation is influenced by energy balance, with significant differences in climatic conditions and energy fluxes between the western and eastern parts of the icefield.