Petermann Glacier, a major outlet glacier of Northern Greenland, drains a marine-based basin vulnerable to destabilization. Using satellite radar interferometry data from the Sentinel-1a/b missions, we observe a seasonal glacier acceleration of 15% in the summer, from 1,250 m/yr to 1,500 m/yr near the grounding line, but the physical drivers of this seasonality have not been elucidated. Here, we use a subglacial hydrology model coupled one-way to an ice sheet model to evaluate the role of subglacial hydrology as a physical mechanism explaining the seasonality in speed. We model the basal effective pressure using the Glacier Drainage System model which then forces the Ice-sheet and Sea-level System Model. We find an excellent agreement between the observed and modeled velocity in terms of magnitude and timing, and conclude that seasonal changes in subglacial hydrology are sufficient to explain the observed seasonal speed up of Petermann Glacier.

This data publication provides all of the scripts and data necessary to initialize and run the subglacial hydrology model and ice sheet model used in this work (Manuscript number 2022GL098009). We also provide the model output and the scripts used to create the figures in the manuscript and the animations in the supplemental document. Several data sets are also made available here, including integrated melt water runoff derived from the regional climate model, MAR (Modèle Atmosphérique Régional), which is used to force the hydrology model, and daily average effective pressure derived from the hydrology model output, which is used to force the ice sheet model. These files combined are sufficient to reproduce all results and figures presented in this work.