Clemens Schannwell
| Department | Climate Variability |
| Group | Ocean Physics |
| Position | Postdoc |
| phone | +49 40 41173-415 |
| clemens.schannwell@mpimet.mpg.de | |
| Room | B 231 |
About me
I am a postdoctoral researcher in the group of Dr Uwe Mikolajewicz. I am a glaciologist and my main research interests are in the area of ice dynamics of glaciers and ice sheets and their interactions with the ocean and atmosphere.
My main tools to study these processes are numerical models and observations from using geophysical methods. I am currently working on the PalMod project which aims to simulate the last 130,000 years with a fully-coupled Earth System Model to investigate climate variability and identify key processes that are driving this variability.
PalMod - From the Last Interglacial to the Anthropocene - Modeling a Complete Glacial Cycle
Scalar - Quantifying millennial timescale grounding-line retreat in East Antarctica
Since November 2019
Postdoc at Max Planck Institute for Meteorology, Germany
June 2017 - November 2019
Postdoc at University of Tübingen, Germany
November 2013- June 2017
PhD in Glaciology University of Birmingham and British Antarctic Survey, UK
2012-2013
MSc by Research in Glaciology, Swansea University, UK
2008-2012
BSc in Geography, University of Bonn, Germany
[14] Schannwell, C., Mikolajewicz, U., Kapsch, M.-L., and Ziemen, F. (2024). A mechanism for reconciling the synchronisation of Heinrich events and Dansgaard-Oeschger cycles. Nature Communications, 15, 2961, https://doi.org/10.1038/s41467-024-47141-7.
[13] Schannwell, C., Mikolajewicz, U., Ziemen, F., and Kapsch, M.-L. (2023). Sensitivity of Heinrich-type ice-sheet surge characteristics to boundary forcing perturbations. Clim. Past, 19, 179–198, https://doi.org/10.5194/cp-19-179-2023.
[12] Višnjević, V., Drews, R., Schannwell, C., Koch, I., Franke, S., Jansen, D., and Eisen, O. (2022). Predicting the steady-state isochronal stratigraphy of ice shelves using observations and modeling. The Cryosphere, 16, 4763–4777, https://doi.org/10.5194/tc-16-4763-2022.
[11] Henry, A. C. J., Drews, R., Schannwell, C., and Višnjević, V. (2022). Hysteretic evolution of ice rises and ice rumples in response to variations in sea level. The Cryosphere, 16, 3889–3905, https://doi.org/10.5194/tc-16-3889-2022.
[10] Kapsch, M.-L., Mikolajewicz, U., Ziemen, F., and Schannwell, C. (2022). Ocean response in transient simulations of the last deglaciation dominated by underlying ice-sheet reconstruction and method of meltwater distribution'. Geophysical Research Letters, 49, e2021GL096767. https://doi.org/10.1029/2021GL096767.
[9] Kapsch, M.-L., Mikolajewicz, U., Ziemen, F. A., Rodehacke, C. B., and Schannwell, C. (2021). Analysis of the surface mass balance for deglacial climate simulations. The Cryosphere, 15, 1131–1156, https://doi.org/10.5194/tc-15-1131-2021.
[8] Schannwell, C., Drews, R., Ehlers, T. A., Eisen, O., Mayer, C., Malinen, M., Smith, E. C., and Eisermann, H. (2020). Quantifying the effect of ocean bed properties on ice sheet geometry over 40 000 years with a full-Stokes model. The Cryosphere, 14, 3917–3934, https://doi.org/10.5194/tc-14-3917-2020.
[7] Drews, R., Schannwell, C., Ehlers, T. A., Gladstone, R., Pattyn, F., and Matsuoka, K. (2020). Atmospheric and oceanographic signatures in the ice‐shelf channel morphology of Roi Baudouin Ice Shelf, East Antarctica, inferred from radar data. Journal of Geophysical Research - Earth Surface, 125, e2020JF005587, https://doi.org/10.1029/2020JF005587.
[6] Schannwell, C., Drews, R., Ehlers, T. A., Eisen, O., Mayer, C., and Gillet-Chaulet, F. (2019). Kinematic response of ice-rise divides to changes in ocean and atmosphere forcing. The Cryosphere, 13, 2673–2691, https://doi.org/10.5194/tc-13-2673-2019.
[5] Schannwell, C., Cornford, S., Pollard, D., and Barrand, N. E. (2018). Dynamic response of Antarctic Peninsula Ice Sheet to potential collapse of Larsen C and George VI ice shelves. The Cryosphere, 12, 2307-2326, https://doi.org/10.5194/tc-12-2307-2018.
[4] Mayer, C., Schaffer. J., Hattermann, T., Floricioiu, D., Krieger, L., Dodd, P. A., Kanzow, T., Licciulli, C., and Schannwell, C. (2018). Large ice loss variability at Nioghalvfjerdsfjorden Glacier, Northeast-Greenland. Nature Communications 9 (1), 2768, doi: 10.1038/s41467-018-05180-x.
[3] Schannwell, C., Barrand, N.E., and Radic, V. (2016). Future sea-level rise from tidewater and ice-shelf tributary glaciers of the Antarctic Peninsula. Earth and Planetary Science Letters, 453, 161-170, http://dx.doi.org/10.1016/j.epsl.2016.07.054.
[2] Schannwell, C., Barrand, N.E., and Radic, V. (2015). Modeling ice dynamic contributions to sea level rise from the Antarctic Peninsula. Journal of Geophysical Research - Earth Surface, 120, 2374-2392, doi: 10.1002/2015JF003667.
[1] Schannwell, C., Murray, T., Kulessa, B., Gusmeroli, A., Saintenoy, A., and Jansson, P. (2014). An automatic approach to delineate the cold-temperate transition surface with ground-penetrating radar on polythermal glaciers. Annals of Glaciology 55 (67), 89-96, doi:10.3189/2014AoG67A102.
Research highlights
How ice rises and rumples affect the Antarctic ice sheet
Wherever ice shelves ground locally on the elevated seabed, ice rises can form, causing the flowing ice shelf to be diverted around the grounded region. On smaller elevated seabed anomalies, ice rumples can form, where the ice shelf flows over the grounded region (see figure 1). These islands surrounded by otherwise floating ice shelves play a key role buttressing discharge from the Antarctic Ice Sheet and regulating its contribution to sea level.
In the study, the authors A. Clara J. Henry and Clemens Schannwell (Max Planck Institute for Meteorology), Vjeran Višnjević and Reinhard Drews (University of Tübingen), investigate the evolution of ice rises. Because there are over 700 ice rises all around Antarctica, it is important to improve the understanding of their role in Antarctic ice sheet dynamics: The Antarctic ice sheet is the largest remaining ice sheet on the planet and has the potential to raise the global sea level by around 58 m. In addition, it is the largest source of uncertainty in sea level rise projections. Coastal Antarctica is particularly susceptible to a changing climate, necessitating a better understanding of the dominant physical processes there.
As climate and sea level change, ice rises respond by either increasing or decreasing in size. The change in size influences the flow of ice and can have an effect on the total Antarctic ice volume. Ice rises hold back or buttress the ice shelf, regulating the flow of ice and influencing the location of the grounding line. Because these features change in size over glacial cycles, they alter ice shelf buttressing. When there is an increase in sea level, ice rises reduce in size and provide less buttressing, increasing the speed of the ice shelf and resulting in a loss of ice from the Antarctic ice sheet. When the sea level decreases, the grounded area of ice rises increases, but with a time delay. This behavior is called hysteresis and has important implications for the Antarctic ice sheet evolution.
Ice rises and ice rumples are found all around the perimeter of the Antarctic Ice Sheet, but the mechanisms governing the transition from one flow regime to the other had previously not been investigated, and influences of the surrounding ice shelves on the local flow regimes had not yet been quantified. In order to explore these questions, the scientists use the three-dimensional, full Stokes model Elmer/Ice to simulate idealized ice rises and ice rumples under various basal friction scenarios and sea level perturbations.
This allows them to identify a hysteretic response of ice rises and ice rumples to changes in the sea level, with grounded area being larger in a sea-level-increase scenario than in a sea-level-decrease scenario. This hysteresis shows not only irreversibility following an equal increase and subsequent decrease in the sea level but also that the perturbation history is important for inferring the past ice rise or ice rumple geometry. The initial grounded area needs to be carefully considered, as this will determine the formation of either an ice rise or an ice rumple, thereby causing different buttressing effects.
Original publication
Henry, C. J., Drews, R., Schannwell, C., & Visnjevic, V. (2022). Hysteretic evolution of ice rises and ice rumples with variations in sea level. The Cryosphere, 16, 3889-3905. doi: 10.5194/tc-16-3889-2022
Contact
Clara Henry
PhD candidate
Max Planck Institute for Meteorology
Email: clara.henry@mpimet.mpg.de
Dr. Clemens Schannwell
Max Planck Institute for Meteorology
Email: clemens.schannwell@mpimet.mpg.de
How ice rises and rumples affect the Antarctic ice sheet
Wherever ice shelves ground locally on the elevated seabed, ice rises can form, causing the flowing ice shelf to be diverted around the grounded region. On smaller elevated seabed anomalies, ice rumples can form, where the ice shelf flows over the grounded region (see figure 1). These islands surrounded by otherwise floating ice shelves play a key role buttressing discharge from the Antarctic Ice Sheet and regulating its contribution to sea level.
In the study, the authors A. Clara J. Henry and Clemens Schannwell (Max Planck Institute for Meteorology), Vjeran Višnjević and Reinhard Drews (University of Tübingen), investigate the evolution of ice rises. Because there are over 700 ice rises all around Antarctica, it is important to improve the understanding of their role in Antarctic ice sheet dynamics: The Antarctic ice sheet is the largest remaining ice sheet on the planet and has the potential to raise the global sea level by around 58 m. In addition, it is the largest source of uncertainty in sea level rise projections. Coastal Antarctica is particularly susceptible to a changing climate, necessitating a better understanding of the dominant physical processes there.
As climate and sea level change, ice rises respond by either increasing or decreasing in size. The change in size influences the flow of ice and can have an effect on the total Antarctic ice volume. Ice rises hold back or buttress the ice shelf, regulating the flow of ice and influencing the location of the grounding line. Because these features change in size over glacial cycles, they alter ice shelf buttressing. When there is an increase in sea level, ice rises reduce in size and provide less buttressing, increasing the speed of the ice shelf and resulting in a loss of ice from the Antarctic ice sheet. When the sea level decreases, the grounded area of ice rises increases, but with a time delay. This behavior is called hysteresis and has important implications for the Antarctic ice sheet evolution.
Ice rises and ice rumples are found all around the perimeter of the Antarctic Ice Sheet, but the mechanisms governing the transition from one flow regime to the other had previously not been investigated, and influences of the surrounding ice shelves on the local flow regimes had not yet been quantified. In order to explore these questions, the scientists use the three-dimensional, full Stokes model Elmer/Ice to simulate idealized ice rises and ice rumples under various basal friction scenarios and sea level perturbations.
This allows them to identify a hysteretic response of ice rises and ice rumples to changes in the sea level, with grounded area being larger in a sea-level-increase scenario than in a sea-level-decrease scenario. This hysteresis shows not only irreversibility following an equal increase and subsequent decrease in the sea level but also that the perturbation history is important for inferring the past ice rise or ice rumple geometry. The initial grounded area needs to be carefully considered, as this will determine the formation of either an ice rise or an ice rumple, thereby causing different buttressing effects.
Original publication
Henry, C. J., Drews, R., Schannwell, C., & Visnjevic, V. (2022). Hysteretic evolution of ice rises and ice rumples with variations in sea level. The Cryosphere, 16, 3889-3905. doi: 10.5194/tc-16-3889-2022
Contact
Clara Henry
PhD candidate
Max Planck Institute for Meteorology
Email: clara.henry@mpimet.mpg.de
Dr. Clemens Schannwell
Max Planck Institute for Meteorology
Email: clemens.schannwell@mpimet.mpg.de
How ice rises and rumples affect the Antarctic ice sheet
Wherever ice shelves ground locally on the elevated seabed, ice rises can form, causing the flowing ice shelf to be diverted around the grounded region. On smaller elevated seabed anomalies, ice rumples can form, where the ice shelf flows over the grounded region (see figure 1). These islands surrounded by otherwise floating ice shelves play a key role buttressing discharge from the Antarctic Ice Sheet and regulating its contribution to sea level.
In the study, the authors A. Clara J. Henry and Clemens Schannwell (Max Planck Institute for Meteorology), Vjeran Višnjević and Reinhard Drews (University of Tübingen), investigate the evolution of ice rises. Because there are over 700 ice rises all around Antarctica, it is important to improve the understanding of their role in Antarctic ice sheet dynamics: The Antarctic ice sheet is the largest remaining ice sheet on the planet and has the potential to raise the global sea level by around 58 m. In addition, it is the largest source of uncertainty in sea level rise projections. Coastal Antarctica is particularly susceptible to a changing climate, necessitating a better understanding of the dominant physical processes there.
As climate and sea level change, ice rises respond by either increasing or decreasing in size. The change in size influences the flow of ice and can have an effect on the total Antarctic ice volume. Ice rises hold back or buttress the ice shelf, regulating the flow of ice and influencing the location of the grounding line. Because these features change in size over glacial cycles, they alter ice shelf buttressing. When there is an increase in sea level, ice rises reduce in size and provide less buttressing, increasing the speed of the ice shelf and resulting in a loss of ice from the Antarctic ice sheet. When the sea level decreases, the grounded area of ice rises increases, but with a time delay. This behavior is called hysteresis and has important implications for the Antarctic ice sheet evolution.
Ice rises and ice rumples are found all around the perimeter of the Antarctic Ice Sheet, but the mechanisms governing the transition from one flow regime to the other had previously not been investigated, and influences of the surrounding ice shelves on the local flow regimes had not yet been quantified. In order to explore these questions, the scientists use the three-dimensional, full Stokes model Elmer/Ice to simulate idealized ice rises and ice rumples under various basal friction scenarios and sea level perturbations.
This allows them to identify a hysteretic response of ice rises and ice rumples to changes in the sea level, with grounded area being larger in a sea-level-increase scenario than in a sea-level-decrease scenario. This hysteresis shows not only irreversibility following an equal increase and subsequent decrease in the sea level but also that the perturbation history is important for inferring the past ice rise or ice rumple geometry. The initial grounded area needs to be carefully considered, as this will determine the formation of either an ice rise or an ice rumple, thereby causing different buttressing effects.
Original publication
Henry, C. J., Drews, R., Schannwell, C., & Visnjevic, V. (2022). Hysteretic evolution of ice rises and ice rumples with variations in sea level. The Cryosphere, 16, 3889-3905. doi: 10.5194/tc-16-3889-2022
Contact
Clara Henry
PhD candidate
Max Planck Institute for Meteorology
Email: clara.henry@mpimet.mpg.de
Dr. Clemens Schannwell
Max Planck Institute for Meteorology
Email: clemens.schannwell@mpimet.mpg.de