Combining geodetic data and summer MODIS albedo anomalies for annual glacier mass balance estimation

Abstract. Annual glacier mass balance time series are essential for understanding the impacts of climate change on glacierized regions. Satellite-based observations enable consistent and regionally comprehensive monitoring of glacier mass balance. While geodetic methods provide reliable estimates over decadal timescales, deriving accurate annual glacier mass balance estimates remains challenging. In this study, we propose a new approach that combines 20 years geodetic mass balance data with glacier-wide average summer albedo anomalies from MODIS to produce reliable annual glacier mass balance estimates for land-terminating glaciers. We generated time series from 2000 to 2024 for 2748 glaciers across three regions: the European Alps, Scandinavia, and Svalbard. Validation against 1108 available in-situ mass balance measurements yielded root mean square errors (RMSE) of 0.45, 0.79, and 0.42 m w.e. and coefficients of determination (R²) of 0.60, 0.44, and 0.35 for the European Alps, Scandinavia, and Svalbard, respectively. These results demonstrate the method’s effectiveness and its potential for application in other glacierized regions.