The sub-seasonal and interannual spatio-temporal variability of bare-ice albedo of Abramov Glacier, Kyrgyzstan

Abstract As snowlines retreat, the bare ice of Central Asian glaciers is increasingly exposed to short-wave radiation and high temperatures. The importance of bare-ice albedo for glacier melt rates is thus rising. Little is known about the variability of bare-ice albedo, its drivers or its implications for glacier melt. We address this gap by presenting the sub-seasonal and interannual variability of bare-ice albedo of Abramov Glacier in Kyrgyzstan between 1999 and 2022. We derived albedo products from Landsat surface reflectance data, investigated the relationship between air temperature and bare-ice albedo variability and explored the implications of this variability for glacier melt. Our results indicate that bare-ice albedo undergoes a sub-seasonal cycle controlled by air temperature and elevation-dependent refreezing events. Bare-ice albedo decreased over the tongue in July and August between 1999 and 2017, while, in 2018, a lateral displacement of the ice resulted in a shift in the patterns of bare-ice albedo. We found significant correlations between bare-ice albedo variability and both temperature and glacier melt at various timescales. Rising temperatures are thus expected to lead to darker bare ice and amplified feedback melt cycles. Integrating albedo variability into glaciological models is thus crucial for accurate predictions of accelerated glacier response to intensifying climate change.