The working group "Marine Climate Research" is an international team equipped with modern technical infrastructure. The staff members of the two research groups "Paleo Oceanography & Paleo Climate" and "Climate Modeling" unite expertise in geology, geochemistry, geography, physics, paleontology and computer modelling to form a research team oriented at multidisciplinary science.

The team studies climate processes using marine climate proxy data (climate indicators) and model simulations and furthermore is active in methodological developments. The group closely collaborates with renowned institutions and receives funding from national and international programmes such as the German Excellence Initiative and the Collaborative Research Centre (SFB) programme of the German Research Foundation (DFG) and the 7^th European Framework Programme for Research and Technological Development.

With respect to periods in time, the working group looks mainly at the past, but takes into account both comparable processes in the present and their implications for the future. By examining selected periods from the past four million years, the researchers analyze the climatic conditions and processes in former times. Studies of past interglacials (warm periods), for example, allow for comparisons with the current interglacial and future climate predictions. Processes are analyzed on time scales of months (e.g. annual phytoplankton development) to years (e.g. characteristics of El-Nino-La Nina events) to centuries (e.g. changes in atmospheric CO₂ concentration) to millennia (climate trends).

Methodologically, we apply both quantitative analyzes for organic and anorganic proxies from marine sediments as well as a global, fully coupled numerical climate models (AOGCM).

Among the large amount of climate proxies, we focus on:

• molecular organical compounds (e.g. alkenones)
• isotopical-chemical characteristics of marine organisms' skeletons (e.g. foraminifera)
• mineralic element distributions (e.g. Mg/Ca ratio)

These proxies are analysed mainly in the two labs of the working group, the Biomarker lab and the ICP-Mass spectrometry lab.

The climate model includes the following components:

• ocean and atmospheric circulation
• sea ice
• marine carbon and nutrient cycles

One of our main tasks is to analyse empirical proxy data in conjunction with with model simulation results. In this manner, we can bridge knowledge gaps of the individual approaches, comprehensively analyze processes and optimize reconstruction methods as well as models.