Response of glaciers in the Suntar-Khayata range, eastern Siberia, to climate change

Following an International Geophysical Year project, we conducted meteorological observations during 2004-07 around the Suntar-Khayata range in eastern Siberia, where a strong temperature inversion exists throughout the winter. The temperature on the flat plain around Oymyakon (∼700ma.s.l.) was ∼20°C lower than that in a glaciated area located at ∼2000ma.s.l. The inversion remained stable from October to April due to the Siberian high. Snowfall was limited to the beginning and end of winter. The stable conditions prevented atmospheric disturbances and inhibited snowfall during midwinter. From 1945 to 2003, glaciers in the Suntar-Khayata range retreated, with an area reduction of 19.3%. To assess this retreat, we estimated the response of the glaciers to climate change. According to US National Centers for Environmental Prediction (NCEP) data, the temperature in this region increased by ∼1.9°C over 60 years. By calculating snow accumulation and ablation, the sensitivity of the equilibrium-line altitude (ELA) to the temperature shift was evaluated. We estimated snow precipitation based on precipitation at <0°C and ablation using the degree-day method. By these estimates, the ELA of Glacier No. 31, assumed 2350 m at present, could rise ∼150 m if temperature rises an average of 1°C. Furthermore, a 1.8°C temperature rise could cause the ELA to rise to 2600ma.s.l., removing the accumulation zone. With no accumulation zone, the glacier body would decrease, roughly halving in volume after ∼400 years.