The export of fresh water (solid and liquid) from glaciers and ice sheets plays an important role in the global climate system. Icebergs influence ocean salinity and circulation patterns and pose a growing hazard to Arctic navigation as sea ice cover declines. Therefore, quantifying the volume of icebergs calved from the Greenland ice sheet is essential. Here, we present iceberg size and volume distributions derived from high-resolution Satellite Pour l’Observation de la Terre (SPOT) images for Upernavik Isfjord, Northwest Greenland, during the 2020 open water season. The iceberg area–volume conversion is constrained by a 3D photogrammetric survey of icebergs within the fjord. By integrating glacier discharge over estimated iceberg residence times, we link remotely sensed iceberg volumes to calving rates at the primary outlet glaciers. We detected 343 769 icebergs with a total volume of 4.7 km$^3$. This corresponds to 88.7% of the estimated solid ice discharge and falls within the derived discharge range of 3.4–12.2 km$^3$. Uncertainties are primarily controlled by variability in residence time, extrapolation of the area–volume relationship beyond its calibration domain and assumptions regarding ice density.

Continuous monitoring of the mass balance of the Greenland ice sheet is crucial to assess its contribution to the rise of sea levels. The GRACE and GRACE-FO missions have provided monthly estimates of the Earth’s gravity field since 2002, which have been widely used to estimate monthly mass changes of ice sheets. However, there is an 11 month gap between the two missions. Here, we propose a data-driven approach that combines atmospheric variables from the ERA5 reanalysis with GRACE-derived mass anomalies from previous months to predict mass changes. Using an auto-regressive structure, the model is naturally predictive for shorter times without GRACE/-FO observations. The results show a high r2-score (> 0.73) between model predictions and GRACE/-FO observations. Validating the model’s ability to reproduce mass anomalies when observations are available builds confidence in estimates used to bridge the GRACE and GRACE/-FO gap. Although GRACE and GRACE-FO are treated equally by the model, we see a decrease in model performance for the period covered by GRACE-FO, indicating that they may not be as well-calibrated as previously assumed. Gap predictions align well with mass change estimates derived from other geodetic methods and remain within the uncertainty envelope of the GRACE-FO observations.