In my PhD project, I will work on improving the radar simulator from my master thesis to simulate radar data for different thermal regimes, basal conditions (ice frozen to bed vs. thawed ice), and internal structures of the ice. Subsequently, I will use this data within a simulation-based inference framework to disentangle how the different conditions inscribe themselves in radar measurements and to derive temperature profiles and basal reflectivity from radar measurements. This would allow for a better characterization of the basal and thermal state of Antarctica’s ice sheet. My PhD project is funded by a scholarship of the Heinrich-Böll-Stiftung.

Ice shelves, which are extensions of ice sheets connected to land but floating on the ocean, encompass over 75% of the Antarctic perimeter and act as an ice wall that restrains grounded glaciers. Within ice shelves, shear zones typically occur from grounding zones where fast outlet glaciers encounter slower floating ice for the first time. Here we investigate mechanisms that determine the evolution and strength of shear zones. This includes the seeding of the shear-zones at glacier outlets near the grounding zone, the evolution of the shear-zone in the mid-shelf region, and the role of shear zones in crevasse formation and iceberg calving at the ice-shelf front. Understanding these processes is crucial for refining computer models that predict Antarctica's contribution to global sea-level rise.

Within the Priority Programme SPP1158 from the German Reserach Foundation, the project QUASNO will investigate changes in snow accumulation and surface mass balance on the plateau of the DML during the last 500 years. It combines new airborne radar measurements, firn core data and statistical techniques to reconstruct spatio-temporal accumulation fields. The outcome will reduce the uncertainty on the role of climate change to global mean sea level rise in the 21st century.

Das Forschungsprojekt beschäftigt sich mit der großflächigen Bestimmung von basalem Schmelzen (also Schmelzen an der Eis-Ozean Kontaktfläche) von Eisschelfen (schwimmende Teile der Eisschilde). Schmelzraten großflächig, dennoch hochauflösend zu bestimmt ist elementar für Vorhersage zur Stabilität von Eisströmen und damit Vorhersagen zum Meeresspeigel. Dies ist mit aktuellen Radarsystemen noch nicht möglich.  Ein neues Radarsystem wird im Zuge einer Promotion und in Kooperation mit dem Institut für Mikrowellentechnik an der Universität Ulm entwickelt und final in der Antarktis getestet.

Predictions of melting glaciers and polar ice sheets require a better understanding of the processes driving their deformation. Here we dive into glacier dynamics by studying Grenzgletscher, Switzerland, using advanced radar technology.

The bed of glaciers can be studied using radar data. Here we map the bed of a glacier in iceland with a special focus to map drumlins, which are hills that forms under glaciers as a result of ice-sediment interactions. By analysing such data, we get a better understanding of the past and current glacier dynamics.

Ice sheets are reacting to the current temperature changes. They are losing mass at the edges, which is contributing to global sea level rise. However, a warmer atmosphere can also hold and transport more water vapor, which can lead to an increase in snowfall, i.e. accumulation, and thus the surface mass balance, especially in East Antarctica. This project will focus on the investigation of accumulation patterns (spatially and temporally) around the German summer station Kohnen on the East Antarctic Plateau using Ground-penetrating radar (GPR) data to illustrate and analyze the near-surface structures and past accumulation rates.

Ice Sheet models used e.g. to project sea level rise are forced by many parameters, some of which are often unknown. One of them is the net mass gain or loss of the ice sheet at the atmospheric boundary condition (surface mass balance). We use the internal layering of the ice sheet to reconstruct the surface mass balance the ice has experienced using a machine learning based method.

Ice crystals are mechanically and dielectrically anisotropic, meaning that their deformation behaviour and capability to transmit electromagnetic waves have a directional dependence. These anisotropic properties transfer to the bulk behaviour of polycrystalline ice in glaciers, ice sheets and ice shelfs. Accordingly, the macroscale flow dynamics of these ice masses depend on the microscale distribution of the orientations of ice crystals (also called 'ice fabric') within them. Thanks to the dielectric anisotropy, ice fabric can be measured with polarimetric radar techniques. In particular, using phase-sensitive radar small differences in the directionally dependent propagation velocities can be observed, allowing to reconstruct the ice fabric. Similarly, the detection of the englacial stratigraphic structure can be improved by applying interferometric techniques to profiles acquired with phase-sensitive radar. This englacial structure again allows to decipher past ice deformation, which is potentially controlled by the ice fabric.

This project is funded by a doctoral scholarship of the German Academic Scholarship Foundation (Studienstiftung des deutschen Volkes).

This BSc project developed an open-source, self-built geoelectric measurement device suitable to perform vertical electrical soundings and profiling in resistivity mapping. The instrument design is low-cost but competes well with professional resistivity meters at moderate electrode spacings.

In this BSc project, ground-penetrating radar data of kinematic waves near the grounding zone of Ekström ice shelf were processed and analyzed. Kinematic waves describe a complex stratigraphic structure caused by the interplay of ice flow and topography controlled spatially variable snow deposition. This structure was extracted to disentangle and better understand the underlying processes that lead to the formation of kinematic waves.