Abstract
Estimating annual glacier mass balance is crucial for assessing climate change impacts and understanding glacier water resource availability. On a regional level, the satellite-based geodetic method provides relevant results but is generally limited to multi-decadal estimates and lacks accuracy on an annual scale.
In this study, we propose a novel method that combines annual glacier-wide albedo anomalies derived from MODIS data with ASTER-based geodetic glacier mass balance estimates to produce annual glacier mass balance estimates at regional scales. This method leverages 20 years of ASTER-derived geodetic mass balance data to calibrate the relationship between annual albedo anomalies and mass balance anomalies, enabling the conversion of relative anomalies into absolute annual mass balance values.
Validation against in-situ measurements from the World Glacier Monitoring Service (WGMS) from 2000 to 2020 was conducted on glaciers in the Alps, Scandinavia, and Svalbard. Results showed a root mean square error (RMSE) of 0.23 m and R² of 0.55 for the Alps, an RMSE of 0.67 m and R² of 0.39 for Scandinavia, and an RMSE of 0.19 m and R² of 0.30 for Svalbard. These results indicate a reasonable agreement with in-situ observations, suggesting the method’s robustness across different glacial environments.
Building on this validated methodology, we have generated time series of annual glacier mass balance from 2000 to 2024 for all glaciers larger than 0.5 km² in the Alps, Scandinavia, and Svalbard. These newly derived datasets offer valuable insights into the temporal variability of glacier mass balance and provide a comprehensive assessment of regional glacier responses to climate change.
This study highlights the potential of integrating remote sensing products to improve large-scale annual glacier mass balance estimations. By leveraging multi-sensor satellite data, we propose a scalable approach to glacier monitoring, which could be extended to other glacierized regions worldwide. The results can contribute to a better understanding of glacier-climate interactions and have implications for water resource management and sea-level rise projections in a warming climate.