Glaciers play a crucial role in the Earth System: they are important water suppliers to lower-lying areas during hot and dry periods, and they are major contributors to the observed present-day sea-level rise. Glaciers can also act as a source of natural hazards and have a major touristic value. Given their societal importance, there is large scientific interest in better understanding and accurately simulating the temporal evolution of glaciers, both in the past and in the future. An important part of my research focuses on modelling the temporal evolution of glaciers. Using insights from ice flow modelling, I also try to enhance our understanding of where and why meteorites tend to concentrate at very specific locations on the Antarctic ice sheet.
Modelling glacier evolution across various spatial scales: from case studies to global glacier modelling
I started my academic journey by modelling the evolution of individual glaciers and ice caps with detailed 3-D ice flow models. More specifically, my PhD (2013-2017) entitled ‘modelling the evolution of glaciers and ice caps in a changing climate’ consisted of modelling the dynamics of a Swiss mountain glacier (Vadret da Morteratsch) and a Greenlandic ice cap (Hans Tausen Iskappe). For this, I used 3-D higher-order ice flow models, which were coupled to surface mass balance models. Additionally, I also developed a visualization toolbox (TopoZeko), and performed a statistical regression analyses on the surface mass balance of the Morteratsch glacier complex.
As a postdoctoral scientist (since October 2017), the focus of my research has more shifted toward modelling larger ensembles of glaciers, i.e. a focus on the regional- to global-scale evolution of glaciers. For this, we use techniques and models that are simpler than those typically used when modelling the evolution of single glaciers at high spatial resolution, but which include ice-flow processes nevertheless. The aim of my first two postdoctoral projects (2017-2019 @ ETH Zürich-WSL Birmensdorf and 2019-2021 @ TU Delft) was to extend the GLObal Glacier Evolution Model (GloGEM) of Huss & Hock (2015, Frontiers in Earth Science) by incorporating a dynamic ice flow component. The newly developed flowline model, GloGEMflow, was applied to the European Alps in order to project the future evolution of all glaciers under the EURO-CORDEX RCM ensemble. GloGEMflow was also used to produce results for the second phase of GlacierMIP and formed the starting point to create a response time inventory of all glaciers in the European Alps. Other applications include studying the evolution of glaciers in the European Alps under 1.0, 1.5 and 2 degree warming, modelling the future evolution of all glaciers in Iceland and Scandinavia, modelling debris cover evolution in High-Mountain Asia and the location of possible future ice-dammed lakes. GloGEMflow is now being used by various groups of scientists through various collaborations.
More recently, I have started exploring the possibility to use 3-D models to simulate the evolution of glaciers at regional- to global scales. The goal of this work is to use techniques that were previously typically used when modelling individual glaciers in detail and now use these for large-scale glacier modelling. Using 3-D techniques is particularly relevant for large glaciers that cover the underlying landscape (often referred to as ice caps), which are difficult to represent with flowline approaches such as OGGM and GloGEMflow.
Glacier hydrology and hydropower
Several collaborations have been established with hydrologists, who use our simulated future glacier evolutions as an input for modelling the future runoff in Alpine regions. This includes partnerships with scientists from WSL Birmensdorf, University of Bern, the École Polytechnique Fédérale de Lausanne (Switzerland), the TU Delft (Netherlands) and the University of Bourgogne (France). I have also participated in a study that estimated the global hydropower and water storage potential that will arise from deglaciating basins during the 21st century. Publications on these topics can be found here.
Antarctic meteorites
From December 2012 to February 2013, I had the unique chance to join a Belgian-Japanese meteorite search expedition on the Nansen ice field on the Antarctic plateau (ca. 2900 m elevation), 120 km south of the Belgian Antarctic Station (Princes Elisabeth). During this expedition hundreds of blue ice samples surface samples were collected and these revealed clear climatic signals at the surface. To constrain the age of the ice, the terrestrial age of selected meteorites (i.e. the time since they entered the atmosphere) was determined. By combining this with satellite derived surface velocities and other sources of information, we tried to better constrain the mechanism behind the Nansen blue ice trap. As of October 2020, we are now combining many different datasets in a machine learning algorithm in order to predict where to find meteorites on the Antarctic ice sheet. This work is led by Veronica Tollenaar, funded through a PhD fellowship of the Fonds de Recherche Scientifique – FNRS.