WG 2:  Biogeochemistry


Dr. Victor Brovkin

MPI for Meteorology, Bundesstr. 53, 20146 Hamburg


Dr. Tatiana Ilyina

MPI for Meteorology, Bundesstr. 53, 20146 Hamburg


Dr. Peter Köhler

Alfred-Wegener-Institut (AWI) Helmholz-Zentrum für Polar- und Meeresforschung, Am Alten Hafen 26, 27568 Bremerhaven


Participating institutions:

1.    Alfred-Wegener-Institut (AWI) Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven
2.    Institut für Biogeochemie und Meereschemie der Universität Hamburg (UHH), Hamburg
3.    Institut für Geowissenschaften der Universität Kiel (CAU), Kiel
4.    MARUM - Zentrum für Marine Umweltwissenschaften der Universität Bremen, Bremen
5.    Max-Planck-Institut für Chemie (MPI-C), Mainz
6.    Max-Planck-Institut für Meteorologie (MPI-M), Hamburg
7.    Potsdam-Institut für Klimafolgenforschung (PIK) e. V., Potsdam



Ice cores provide compelling evidence that glacial-interglacial changes in climate and greenhouse gases are tightly coupled. The long-term goal of WG2 in PalMod is to understand processes controlling this coupling and to quantify feedbacks between biogeochemistry and climate during glacial cycles using Earth System Models. In the 2nd phase, the main challenge for WG2 is to apply project ESMs for fully-coupled interactive climate-carbon cycle simulations through the last deglaciation (21 to 6 ka). Such simulations were never done before with full-scale ESMs. In addition to deglaciation runs, WG2 will also perform millennial-scale ESM simulations to analyze the carbon and CH4 cycle variability during abrupt climate events in MIS-3 and to compare them with available data together with WG3. To prepare fully-coupled interactive climate-biogeochemistry simulations through the last glacial cycle in the 3rd phase, first simulations of the glacial inception (125-110 ka) with prescribed atmospheric CO2 concentration for physics but prognostic CO2 concentration in biogeochemistry will be performed in cooperation with WG1.

Our general strategy is to use the model ensemble developed in phase 1: AWI-ESM, CESM, MPI-ESM. The principal feature of the global carbon cycle is that it strongly depends on the physical climate components: atmospheric and ocean circulations, as well as the cryosphere. Therefore, setting up the biogeochemical components (land vegetation and carbon cycle, ocean biogeochemistry) for transient simulations will be done in close interaction with WG1 packages 1.1 to 1.3. Every ESM team will prepare biogeochemistry models for the transient runs in coupled setup, when changes in land and ocean carbon fluxes simultaneously influence atmospheric CO2 concentration and, consequently, climate. A particular challenge in the 2nd phase is to couple land and ocean biogeochemical exchange in shelf regions induced by sea-level changes in co-operation with the CC.2 theme. Experiments with the two orders-of-magnitude faster EMIC CLIMBER-X will serve as a guideline for transient simulations with ESMs.