Simulating surface height and terminus position for marine outlet glaciers using a level set method with data assimilation

TL;DR

This paper presents a data assimilation framework combining a level set method with the shallow shelf approximation to accurately simulate and predict the surface height and terminus position of marine outlet glaciers, demonstrated on idealized and real glaciers.

Contribution

It introduces a novel integration of level set methods with data assimilation for dynamic glacier modeling, improving tracking of glacier terminus and surface changes.

Findings

Effective tracking of seasonal and multi-year glacier cycles.

Improved accuracy in glacier terminus position predictions.

Successful application to Helheim Glacier with remote sensing data.

Abstract

We implement a data assimilation framework for integrating ice surface and terminus position observations into a numerical ice-flow model. The model uses the well-known shallow shelf approximation (SSA) coupled to a level set method to capture ice motion and changes in the glacier geometry. The level set method explicitly tracks the evolving ice-atmosphere and ice-ocean boundaries for a marine outlet glacier. We use an Ensemble Transform Kalman Filter to assimilate observations of ice surface elevation and lateral ice extent by updating the level set function that describes the ice interface. Numerical experiments on an idealized marine-terminating glacier demonstrate the effectiveness of our data assimilation approach for tracking seasonal and multi-year glacier advance and retreat cycles. The model is also applied to simulate Helheim Glacier, a major tidewater-terminating glacier of the Greenland Ice Sheet that has experienced a recent history of rapid retreat. By assimilating observations from remotely-sensed surface elevation profiles we are able to more accurately track the migrating glacier terminus and glacier surface changes. These results support the use of data assimilation methodologies for obtaining more accurate predictions of short-term ice sheet dynamics.