Assessing glacier mass sensitivity to climate variability using GRACE/-FO

In many mountain regions, glaciers constitute an essential freshwater reservoir and represent a critical water supply for downstream populations during droughts. Moreover, glacier mass changes provide a direct and valuable indicator of ongoing climate change. While long-term glacier mass loss is well documented, the drivers of temporal variability in regional glacier mass balance remain poorly constrained, despite their importance for understanding regional glacier–climate interactions.

Satellite gravimetry missions Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) provide direct observations of mass variations at monthly timescales with global coverage over the past two decades. Here, we use GRACE/-FO Level-3 products to estimate glacier mass changes over some regions of the Randolph Glacier Inventory (RGI v6.0) and to investigate their sensitivity to climate variability. Two GRACE/-FO solutions are considered: a solution based on Multichannel Singular Spectrum Analysis (M-SSA), and the SAGSA ensemble solution combining products from multiple processing centers. Signal leakage and separation effects related to the coarse spatial resolution of gravimetry are mitigated using geometry-based approaches, enabling regional mass balance estimates.

Monthly region-wide glacier mass balance are then used to explore relationships with key climate-related drivers, with an initial focus on near-surface air temperature and precipitation derived from the ERA5 reanalysis. This study aims to explore the links between glacier mass variability and climate-related drivers using GRACE/GRACE-FO observations.