Tools
In our studies, we use different models of the Earth system as well as statistical methods to analyse instrumental and proxy data. Analysing paleoclimate records and model results in tandem allows for an improved understanding of climate transitions and the identification of forcing and feedback mechanisms in the climate system.
Paleoclimate simulations with complex Earth System Models
For our simulations we use different earth system models in coupled an uncoupled modes.To include all major climate components such as land vegetation, the cryosphere, and the marine biosphere in our simulations we use the earth system model MPI-ESM, and the precursor version ESM-COSMOS. Such models provide a laboratory for the numerical simulation of various past climates as well as for future climate changes. As a new feature, we implemented an interactive cryosphere into the model and adapt the model system for long-term climate simulations.
The Finite Element Sea-Ice Ocean Model (FESOM) which was developed at the Alfred Wegener Institute, uses an unstructured triangular surface mesh which allows to locally increase the resolution in an otherwise coarser global setup without grid nesting techniques. This enables a regional downscaling for particular areas of interest in a global setup. The earth system model AWI-CM (coupling of FESOM with the atmosphere model ECHAM6) is also a novel model development from our institute. In climate scenarios, long-term changes can be evaluated on focussed areas such as coasts or polar latitudes.
Examples from our research:
Temperate rainforests near the South Pole during peak Cretaceous warmth
Mid-Holocene Atlantic circulation
Isotope Modelling
Water and carbon isotopes are widely used as climate proxies in paleoclimate research. They can be seen as a “common currency” among many different types of climate archives, e.g. ice cores, marine and lake sediments, speleothems, corals, tree rings, and others. The isotope variations stored in these archives allow reconstructing past changes of regional temperatures, precipitation amounts and the Earth’s water cycle, as well as the carbon cycle properties.
Some of our tools have been equipped with explicit isotope diagnostics, especially water isotopes. Such isotope-enabled general circulation models provide a mechanistic understanding of the physical and environmental processes influencing the isotopic composition of different branches of the climate system. Climate simulations with isotope-enabled models are therefore very useful for an improved interpretation of present and past climate variability.
Examples from our research:
Stable water isotopes in ECHAM5/MPI-OM
Dynamic system theory and conceptual modells
In addition to our work with complex climate modells, we make use of statistical data analyses and develop simplified as well as conceptual modells.
This combined approach has been successfully applied at different scientific problems, e.g., relating to feedback mechanisms and the fundamental dynamic of our climate system. By means of data analysis, we decipher different climate modes. To do so, we make use of manyfold statistical tools and environmental data. In this context, we work closely together with different working groups inside and outside of our institute.
In addition we develop modells of the record system and apply them to investigate how the climate adaptions are reflected in the data of the climate archives.
Examples from our research:
Abrupt climate and weather changes across time scales
Temperatures from energy balance models: the effective heat capacity matters
Atmospheric bridge on orbital time scales
