Status: this preprint is open for discussion and under review for The Cryosphere (TC).
State and parameter estimation for Ronne Ice Shelf over 1992–2018
Daniel Cheng,Ian Fenty,Eric Larour,and Surendra Adhikari
Abstract. Projections of sea level change require ice sheet models that reconcile observations with ice flow dynamics to constrain poorly observed processes and parameters. We use the Ice-sheet and Sea-level System Model (ISSM) to construct a state and parameter estimate of Ronne Ice Shelf (RIS) and its drainage basin from 1992 to 2018. We assimilate time-varying observations of surface velocity and elevation change to reconstruct a dynamically consistent model of time-mean basal friction and ice rheology, and sub-shelf basal melting rates. Relative to existing methods, we reduce uncertainty weighted root mean square errors (RMSE) in elevation change and velocity by 21.2 % and 43.6 %, respectively. Our inferred basal melt estimates capture spatio-temporal patterns driven by ocean currents at 5 km spatial resolution, and match monthly amplitudes 43.1 % closer to observations relative to existing estimates. Detrended mass change in the upstream grounded basin also correlates with Gravity Recovery and Climate Experiment (GRACE-GFZ) estimates (R = 0.754). This physically-consistent 26-year reconstruction provides a framework for applications to Antarctica and beyond, with implications for prognostic modeling and future sea level projections.
Received: 09 Oct 2026 – Discussion started: 21 Oct 2026
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In Figure 9 on panels h-j, the site labels are mixed up (R14, R15, Site5a) - compared to ApRES melt rates from Fig 2 (R10, R14, R15) in https://doi.org/10.1029%2F2022JC018879. It is unclear if that mixup is only for the ApRES sites or also for the other time series on those panels. If the inconsistency is for whatever reason between the available ApRES time series data and the Fig 2 please let the authors (me) know so that it can be fixed on our side.
Understanding how Antarctic ice shelves evolve over time is critical for predicting future sea level rise, yet direct measurements of ice and below it are sparse. We combine satellite observations of ice velocity and height change with a physics model to reconstruct 26 years of melting and sub-surface changes beneath Antarctica's Ronne Ice Shelf. Our estimates better match available measurements than existing approaches, and independently agree with gravity-based mass change data.
Understanding how Antarctic ice shelves evolve over time is critical for predicting future sea...
In Figure 9 on panels h-j, the site labels are mixed up (R14, R15, Site5a) - compared to ApRES melt rates from Fig 2 (R10, R14, R15) in https://doi.org/10.1029%2F2022JC018879. It is unclear if that mixup is only for the ApRES sites or also for the other time series on those panels. If the inconsistency is for whatever reason between the available ApRES time series data and the Fig 2 please let the authors (me) know so that it can be fixed on our side.
Nice to see work like this coming out.
-Irena