Dynamic and thermodynamic behaviour of ice sheets and glaciers

Ralf Greve and Shin Sugiyama

 Inland ice sheets and glaciers are an important dynamic part of the Earth's climate system on the time scale of decades and beyond. More than 90% of the terrestrial freshwater reserves are stored in these ice masses. Their complete disintegration would lead to a global sea-level rise of approximately 70 meters and would have severe impacts on the atmospheric and oceanic circulation. Against the background of future global warming due to ongoing emissions of greenhouse gases, research into the behaviour of ice sheets and and glaciers is of great relevance.

 We conduct numerical simulations and field observations in order to reconstruct the evolution of ice sheets and glaciers in the past and predict their future changes. Dynamic/thermodynamic ice sheet models are used to investigate the glaciation of the northern hemisphere during past glacial-interglacial cycles, the past and present state of the Antarctic and Greenland ice sheets, and their response to future global-warming scenarios. Flow simulations are also an important tool for dating ice cores drilled in Antarctica, Greenland and ice caps in high mountains.

 In order to better understand the physical processes which control the changes of ice sheets and glaciers, field measurements on ice dynamics, glacier hydrology and mass balance are performed in the Alps, Kamchatka, Alaska, Patagonia and Antarctica. Field data are analyzed with the aid of numerical simulations and laboratory experiments. A new field of research is the study of extraterrestrial ice masses like the Martian polar caps or the suspected icy shell of the Jovian moon Europa.

Ralf Greve
- Simulation of rapid dynamical changes of the Greenland ice sheet in response to global warming
- Assessing the timing, extent and volume of Tibetan Plateau ice during the last 130,000 years by numerical simulations [external link]
- Induced anisotropy, fast ice flow and climate change in ice sheets
- Evolution and dynamics of the Martian polar ice caps over climatic cycles
- Heinrich Event INtercOmparison HEINO [external link]
- Development of the ice-sheet model SICOPOLIS

Shin Sugiyama
- Three-dimentional numerical modeling of Shirase Glacier drainage basin in the East Antarctic ice sheet [in Japanese]
- Physical structure of snow surface in the Antarctic ice sheet [in Japanese]
- Investigation of glacier fluctuation mechanism due to the formation of an proglacial lake [in Japanese]
- Mechanism of a drainage divide formation in mountain glaciers [in Japanese]
- Short-term variations in glacier flow at Perito Moreno Glacier, Southern Patagonian Ice Field, Argentina [in Japanese]

Physical and chemical properties of ice cores and reconstruction of paleoenvironments

Yoshinori Iizuka

 As a documentation of earth's history, ice core in polar ice sheets records paleoclimatic signals during several hundred thousand years. To accurately interpret the paleoclimatic signals, researchers must pay careful attention to the various physical and chemical processes that can alter ice-core properties. Our research group intends to examine how these processes affect climate information stored in ice core by using new tools and new methods for ice core analyses of x-ray and laser scattering.

Yoshinori Iizuka
- Physical properties of ice cores and paleoclimate/paleoenvironment reconstructions [in Japanese]

Places we visited for research

 We go out to Alps, Alaska or Antarctic where the glacier exists for investigation.And we often take part in meeting held in overseas and exchange opinions with foreign scholar.