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

Abstract. We quantify the snowmelt-albedo feedback at Neumayer Station, East Antarctica, using 24 years (1992–2016) of high-quality meteorological observations to force a surface energy balance model. The modelled 24-year cumulative surface melt at Neumayer amounts to 1060 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 fresh snow density, yielding a range of 800–1140 mm w.e. Melt at Neumayer occurs only in the months November to February, with a summer average of 46 mm w.e. and large interannual variability (σ = 40 mm w.e.). Absorbed shortwave radiation is the dominant driver of temporal melt variability at Neumayer. To assess the importance of the melt-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 three times weaker, demonstrating how important it is to correctly represent this feedback in model simulations of surface melt.