Annual mass balance time series for the Tien Shan and Pamir from 2000 to 2018

Annual mass time series for Central Asia were calculated using the transient snowline position and its rate of change during the ablation season to constrain the winter snow accumulation and the melt parameters of a distributed accumulation and temperature-index model for each glacier and year individually. This method is based on Barandun et al., 2018, TC and was regionally applied in Barandun et al., accepted, GRL (GRL mannuscript identifier: 2020GL092084). The transient snowline on a glacier marks the transition between the ice and snow surface, thus approximates the zero-mass balance line of the glacier during the ablation season. The snowline is hence a proxy for the surface mass balance. Automatic snowline mapping at the scale of individual glaciers on over 3,000 Landsat surface reflectance products provided a total of 255,000 snowlines from 2000 to 2018 for the region. As a second-order calibration, we calculated geodetic mass balances using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) scenes and High Mountain Asia Digital Elevation Models (HMA DEMs).

Our mass balance calculations, tied to transient snowline observations, provided annual mass balance time series for 1,222 (61%) glaciers greater than 2km2 located in the Tien Shan and Pamir. Details on the methods can be found in:

Barandun, Martina, Matthias Huss, Ryskul Usubaliev, Erlan Azisov, Etienne Berthier, Andreas Kääb, Tobias Bolch, and Martin Hoelzle. "Multi-decadal mass balance series of three Kyrgyz glaciers inferred from modelling constrained with repeated snow line observations." The Cryosphere 12, no. 6 (2018): 1899-1919.

These annual time series have been presented in: 

Barandun, Martina, Eric Pohl, Kathrin Naegeli, Robert McNabb, Matthias Huss, Etienne Berthier, Tomas Saks and Martin Hoelzle. "Hot spots of glacier mass balance variability in Central Asia". Geophysical Research Letters, accepted (GRL mannuscript identifier: 2020GL092084).