This work was funded by US National Science Foundation (NSF) Office of Polar Programs grants ANT-0423595 and ANT-0233823 and the Earth System Modeling program of the Office of Biological and Environmental Research within the US Department of Energy’s Office of Science.
Journal of Glaciology
McMurdo Dry Valleys (Antarctica), Glaciers -- Ecological aspects, Glaciers -- Antarctica -- Taylor Valley, Ablation (Aerothermodynamics)
The McMurdo Dry Valleys of Antarctica host the coldest and driest ecosystem on Earth, which is acutely sensitive to the availability of water coming from glacial runoff. We modeled the spatial variability in ablation and assessed climate sensitivity of the glacier ablation zones using 16 years of meteorological and surface mass-balance observations collected in Taylor Valley. Sublimation was the primary form of mass loss over much of the ablation zones, except for near the termini where melt, primarily below the surface, dominated. Microclimates in ~10 m scale topographic basins generated melt rates up to ten times higher than over smooth glacier surfaces. In contrast, the vertical terminal cliffs on the glaciers can have higher or lower melt rates than the horizontal surfaces due to differences in incoming solar radiation. The model systematically underpredicted ablation for the final 5 years studied, possibly due to an increase of windblown sediment. Surface mass-balance sensitivity to temperature was ~−0.02 m w.e. K−1, which is among the smallest magnitudes observed globally. We also identified a high sensitivity to ice albedo, with a decrease of 0.02 having similar effects as a 1 K increase in temperature, and a complex sensitivity to wind speed.
MATTHEW J. HOFFMAN, ANDREW G. FOUNTAIN and GLEN E. LISTON (2016). Distributed modeling of ablation (1996–2011) and climate sensitivity on the glaciers of Taylor Valley, Antarctica. Journal of Glaciology.