Gerrit Lohmann, Alfred Wegener Institute for Polar and Marine Research, Bremerhaven

Ralph Schneider, Institute for Geosciences, Christian-Albrechts-University, Kiel

Johann Jungclaus, Max Planck Institute for Meteorology, Hamburg

http://www.geo.uni-bremen.de/interdynamik/

The major objective of the project is to investigate the spatio-temporal pattern of temperature changes during the Eemian and Holocene as derived from integrations with a comprehensive global climate model, marine surface ocean temperature and oxygen isotope records as well as from terrestrial archives on a global scale.

We will explore the worldwide distribution of existing, reedited, and newly collected marine and terrestrial palaeotemperature data and compare it with results from transient experiments with a state-of-the-art general circulation model used in the assessment of future climate change. The palaeodata collection and the modelling efforts will aim to investigate the regionally very different temporal climate patterns during the middle to late Holocene (the last 6,000 years) and the Eemian (125,000 years before present). Special emphasis is placed on the last 3000 years, striving to complement a former low-resolution study of the Holocene. With advanced statistical analysis of spatial and temporal variability in the palaeodata records and in the model results, natural climate variability modes and their amplitude will be identified in the data and compared with the climate variability tracked down in the model experiments. Pattern analysis will unravel heterogeneity in temperature trends. The extension of the Latest Holocene climate simulations into the next centuries, using scenarios for future greenhouse gas emission, can help to assess future climatic change influenced by natural and anthropogenic “forcing”. The statistical analyses will extract climate phenomena from different proxy time-series and elaborate common variability and teleconnections for the last two interglacial periods. The aim is to unravel the influence of internal variability and natural forcing factors, like e.g. parameters of the Earth's orbit, on climate variability and regional heterogeneity in climate trends. The variations in the large-scale ocean circulation and feedback mechanisms between thermohaline circulation changes and low-frequency variations of climate will be investigated.