The German climate modelling initiative (PalMod II) is funded by the Federal Ministry of Education and Science (BMBF) through the Research for Sustainability initiative (FONA) as a follow-up project to PalMod. The project aims to simulate a complete glacial-interglacial cycle using complex Earth system models.

An important assumption for consistent Earth system models over the glacial cycle is the modelling, understanding and quantification of the feedback between individual climate-relevant components. The last glacial-interglacial cycle, especially the termination of the last glacial period, is one of the best constrained global-scale climate change signal in Earth history documented by climate archives. Nevertheless, the understanding of the underlying dynamics is still limited, especially for epochs preceding the Last Glacial Maximum (LGM, 21,000 years before present) and with respect to abrupt climate shifts and associated changes in sea level and in the Atlantic meridional overturning circulation (AMOC) during glacial and interglacial periods (to name just two of them). In order to simulate these changes using Earth system models, various components such as the feedback of dynamic ice sheets to the Earth system must be implemented.

The section 1.3 is involved in the following project: Key processes of the solid Earth, ice an ocean

 Based on the first PalMod phase, the working group WG1.4 of PalMod II will investigate the key processes of the solid Earth, ice and ocean as well as their interaction. The focus is on the Southern Ocean and Antarctica. The aim is to understand the interactions between the model components as well as to improve model parameterizations for the coupled models. This is important for the coupled model systems focusing on small-scale and transient processes. The subproject TP1, located in this section at the GFZ, investigates the influence of the solid Earth on palaeoclimate dynamics. The model component VILMA (Viscoelasic Lithosphere and Mantle) describes the deformative feedback of the solid Earth (glacial-isostatic adjustment) as well as the gravitative consistent sea level change. The focus will be on lateral variations of the lithospheric structure and the viscosity of the Earth's mantle and their interaction with the dynamic Antarctic ice sheet.

 Topics that will be discussed are:

• Refinement of the three-dimensional viscoelastic Earth model VILMA for use global climate models and analysis of transient small-scale processes
• Implementation of a high-resolution sub-shelf cavity system
• Coupled simulations for a projection of the melting of the Antarctic ice sheet
• Investigations on feedback between ocean, ice shelf and solid Earth

Funding: BMBF - Bundesministerium für Bildung und Forschung

Funding period: 01.12.2019 - 30.11.2022

Website: www.palmod.de