Quantifying the snowmelt–albedo feedback at Neumayer Station, East Antarctica

Abstract

We use 24 years (1992–2016) of high-quality meteorological observations at Neumayer Station, East Antarctica, to force a surface energy balance model. The modelled 24-year cumulative surface melt at Neumayer amounts to 1154 mm water equivalent (w.e.), with only a small uncertainty (±3 mm w.e.) from random measurement errors. Results are more sensitive to the chosen value for the surface momentum roughness length and new snow density, yielding a range of 900–1220 mm w.e. Melt at Neumayer occurs only in the months November to February, with a summer average of 50 mm w.e. and large interannual variability (σ=42 mm w.e.). This is a small value compared to an annual average (1992–2016) accumulation of 415±86 mm w.e. Absorbed shortwave radiation is the dominant driver of temporal melt variability at Neumayer. To assess the importance of the snowmelt–albedo feedback we include and calibrate an albedo parameterisation in the surface energy balance model. We show that, without the snowmelt–albedo feedback, surface melt at Neumayer would be approximately 3 times weaker, demonstrating how important it is to correctly represent this feedback in model simulations of surface melt in Antarctica.