PRODEM-Xtract: a Python tool for extracting high-resolution annual ice elevation along Greenland flux gates

The Greenland Ice Sheet is a key component of the Earth’s climate system and assessing its mass balance is crucial for predicting sea-level rise. Solid ice discharge is a critical parameter that can be determined by calculating the mass flux through gates spanning all outlet glaciers. However, this calculation relies on accurate ice-thickness measurements. Here, we present an open-source Python package (PRODEM-Xtract) to extract high-resolution annual ice surface elevation and associated ice-thickness profiles along user-defined flux gates over the marginal zone of the Greenland Ice Sheet. PRODEM-Xtract builds on PRODEM, an annual series (2019–2024) of Digital Elevation Models covering the margin of the Greenland Ice Sheet, while further refining the product to deliver a higher spatial resolution of 32 metres. Bed topography is derived from BedMachine v6. Using PRODEM-Xtract, we analyse changes in surface elevation and corresponding ice thickness along flux gates across the three largest outlet glaciers of the Greenland Ice Sheet, for which we observe complex spatial and temporal variability over the period from 2019 to 2024 (inclusive). The evolving annual ice thickness will be incorporated into future assessments of the dynamic ice discharge from the Greenland Ice Sheet.