Glaciares de Chile


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

Bravo, C., A. Ross, D. Quincey, S. Cisternas and A. Rivera (2021): Journal of Glaciology, 1–14.

Resumen / 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 72Wm-² to the west and 51Wm-² to the east) and net shortwave radiation
(mean of 54Wm-² to the west and 52Wm-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 (−4Wm-²) and a source in the west (20Wm-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.