Ocean circulation Ocean dynamics in the deep sea in the past
Ocean dynamics play a decisive role in the climate system as a buffer for the heat balance and as the largest active carbon reservoir. Many of our research projects therefore concern the reconstruction of ocean dynamics in the past. The isotope ratio of 143Nd/144Nd has been developed since the late 1990s as a new tool in palaeoceanography and, along with radiocarbon, is an important trace element of deep water movement.
The radiogenic isotope ratio 143Nd/144Nd can be used to trace the circulation pathways of water in the deep sea and/or to determine the origin of water masses. However, the Nd cycle in the ocean is still incompletely understood and studies of seawater, sediments and corals are needed to better understand the modern cycle of this element, its isotopy and its evolution in the past. We have been working for many years on the distribution, temporal variation, sources and sinks of this tracer. Our current focus is on the reconstruction of the isotope gradient in the Atlantic since about 1 million years ago. The use of radiocarbon as an indicator of ocean circulation and the carbon cycle has been well known since the late 1960s. Thanks to massive improvements in accelerator mass spectrometry, radiocarbon has become an increasingly important tracer for the study of ocean circulation. This provides information about the time of formation of water masses and their mixing today as well as in the near past (0-40000 years). Our research benefits from very strong support from the DFG SPP527 International Ocean Discovery Programme and other individual DFG projects. The links refer to the ongoing projects and our publications provide a broad overview of the research results to date.
