Predicting the response of the future ocean to climate change requires understanding the past ocean through reliable proxy data. Planktic foraminifers are a widespread tool for accessing paleoceanographic and paleoclimatic conditions due to the high preservation potential of their calcareous tests, which accumulate on the sea floor. Inhabiting mostly the first 200 m of the water column makes them particularly useful for reconstructing the dynamics and biogeochemical cycles of the upper ocean. Nevertheless, the interpretation of proxy data derived from the shell chemistry of planktic foraminifers requires fundamental knowledge of their distribution and ecology. The present study aims to characterize modern planktic foraminiferal assemblages in the eastern North Atlantic Ocean at a latitudinal transect from the polar circle to the equator. Plankton tow samples were taken onboard S/Y Eugen Seibold during 2020 and 2021. A wide spectrum of in-situ measurements of seawater properties and discrete samples was obtained during the expeditions and complements the dataset. Element to calcium ratios (El/Ca) of the foraminiferal tests are compared to the geochemistry of ambient seawater and discussed for the varying biogeographical provinces sampled along the transect. This will provide important insights into the use of planktic foraminiferal shell chemistry for the reconstruction of the dynamics of the surface ocean.

Primary Presenter: Lena Heins, Max Planck Institute for Chemistry (lena.heins@mpic.de)

Authors:

Lena Heins, Department of Climate Geochemistry, Max Planck Institute for Chemistry, Mainz, Germany  ()

Aaron Bieler, Department of Climate Geochemistry, Max Planck Institute for Chemistry, Mainz, Germany and Department of Earth Sciences, ETH Zürich, Switzerland  ()

Maria Calleja, Department of Climate Geochemistry, Max Planck Institute for Chemistry, Mainz, Germany and Marine Ecology and Systematics (MarES) group, Biology Department, University of the Balearic Islands, Palma de Mallorca, Spain  ()

Hans Slagter, Department of Climate Geochemistry, Max Planck Institute for Chemistry, Mainz, Germany  ()

Hedy Aardema, Department of Climate Geochemistry, Max Planck Institute for Chemistry, Mainz, Germany and Department of Earth Sciences, ETH Zürich, Switzerland  ()

Isabella Hrabe de Angelis, Department of Multiphase Chemistry, Max Plank Institute for Chemistry, Mainz, Germany  ()

Antonis Dragoneas, Department of Climate Geochemistry, Max Planck Institute for Chemistry, Mainz, Germany  ()

David Walter, Department of Climate Geochemistry, Max Planck Institute for Chemistry, Mainz, Germany  ()

Hubert Vonhof, Department of Climate Geochemistry, Max Planck Institute for Chemistry, Mainz, Germany  ()

Alfredo Martinez-Garcia, Department of Climate Geochemistry, Max Planck Institute for Chemistry, Mainz, Germany  ()

Ralf Schiebel, Department of Climate Geochemistry, Max Planck Institute for Chemistry, Mainz, Germany  ()

Gerald Haug, Department of Climate Geochemistry, Max Planck Institute for Chemistry, Mainz, Germany and Department of Earth Sciences, ETH Zürich, Switzerland  ()