National climate modelling initiative

The project aims at parametrising and validating a viscoelastic earth model for applications in earth-system models, which are applied in the national paleo climate modelling initiative (PalMod) . PalMod is funded by the Federal Ministry of Education and Science (BMBF) as Research for Sustainability initiative (FONA) to understand climate system dynamics and variability during the last glacial cycle.


The working Group 1, 'Physical Systems', aims at the modelling, understanding and quantification of feedbacks between climate components during glacial cycles. 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 (BP)) and with respect to abrupt climate shifts and associated changes in the sea level and Atlantic meridional overturning circulation (AMOC) during glacial and interglacial periods (to name just two of them). The current generation of state-of-the-art Earth System Models (ESMs) is not able to simulate these changes, as several necessary features (e.g. interactive ice sheets and related feedbacks) have not yet been implemented. The working group aims at the implementation of the missing components into state-of-art model systems and the subsequent transient simulation of the last termination with only greenhouse gases (GHGs) and insolation specified.

The section 1.3 is involved in two projects:

The overarching goal of the work package WP1.1 'Coupling of ice sheet models with AOGCMs' is development of coupled model systems (atmosphere-ocean-ice sheets-solid Earth) that will be used for the transient simulations. This involves the general setup, the test of various effects/parametrisations and the incorporation of important processes (e.g. interactive land sea mask, dust) into the model systems. The model systems will contain interactively coupled atmosphere-ocean-ice-sheet-solid earth models. All components will be state-of-the-art models.

The task of section 1.3 there in is to implement the solid-earth component VILMA which determines the deformation response of the solid earth to surface mass redistributions on time scales from 10 to 100,000 years and the resulting sea-level variations in a gravitationally consistent manner. In accordance, this model is aimed to represent the solid earth module in the earth-system models under investigation in PalMod.

Topics that will be discussed are:

  • coupling mechanisms due to changes in the land-ocean mask
  • surface-load induced topography changes of the continental areas
  • influence of relative sea level at the marine-based ice margins of the continental ice sheets. 

Therein, the goal of the work package 1.2, 'Scale interactions', which is coordinated by Section 1.3, is to validate the physical simulations for not yet implemented processes and resolutions that impact individual components as the overall performance of the coupling efforts. Furthermore, several sub-grid scale processes will be resolved for the cryosphere, the atmosphere, the ocean, the solid earth and the land systems. This work will develop new parameterisations or optimize the parameters of existing parameterizations. The main tasks of Section 1.3 will be to analyse qualitative and quantitative aspects of the solid earth's mechanical behaviour. These will be investigated in relation to the earth system models and process under consideration in PalMod. 

Following aspects will be considered:

  • effects due to coupling with other model components due to the deformability of the solid earth
  •  independent validations of the deformation state by means of sea-level height proxies
  • prediction of sea-level variation
  • assessment of specific rheological aspects like 3D structure or non-linearities in the mechanical behaviour of lithosphere and upper mantle to be implemented in the modelling set up of PalMod.


Latinovic, M. , Klemann, V., Irrgang, C., Bagge, M., Specht, S., Thomas, M. (2018): A statistical method to validate reconstructions of late-glacial relative sea level – Application to shallow water shells rated as low-grade sea-level indicators.  - Climate of the Past Discussions, {}, in review.

Funding: BMBF -  Federal Ministry of Education and Research

Funding period: completed 

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