Abundance of organic-walled dinoflagellate cysts of sediment core GeoB3603-2


Here, we reconstruct the varying influence of the Agulhas Current (AgC), the South Atlantic Current and the Antarctic Circumpolar Current on the Agulhas Retroflection (AgR) in the eastern South Atlantic Ocean for the last 160,000 years on the basis of the dinoflagellate cysts, pollen and spores present in a sediment core (GeoB 3603-2) from the southeastern Cape Basin offshore South Africa, where the Agulhas Current enters the Atlantic Ocean. Our analyses reveal strong orbital forcing on the heat exchange between the Indian Ocean and the South Atlantic Ocean during the Late Quaternary. Maxima in local productivity appear to be primarily related to a strengthening of the ocean circulation as a result of the high seasonal contrast during precession maxima. During precession minima, seasonal contrast was low and stratified, oligo- to mesotrophic conditions prevailed, notably when these minima coincided with the glacial terminations. The clear presence of periodicities on a sub-Milankovitch scale as well as modulations of the primary frequencies demonstrate that the Agulhas Retroflection furthermore is modulated substantially by complex interactions between the subtropical, 'precession-driven', climate and ocean circulation systems, and the southern, 'obliquity-driven', high latitudes.

Supplement to: Esper, Oliver; Versteegh, Gerard J M; Zonneveld, Karin A F; Willems, Helmut (2004): A palynological reconstruction of the Agulhas Retroflection (South Atlantic Ocean) during the Late Quaternary. Global and Planetary Change, 41, 31-62

DOI https://doi.org/10.1594/PANGAEA.58937
Related Identifier https://doi.org/10.1016/j.gloplacha.2003.10.002
Related Identifier https://nbn-resolving.org/urn:nbn:de:gbv:46-ep000103156
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.58937
Creator Esper, Oliver ORCID logo; Versteegh, Gerard J M ORCID logo; Zonneveld, Karin A F ORCID logo; Willems, Helmut
Publisher PANGAEA
Publication Year 2004
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Language English
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 5400 data points
Discipline Geosciences; Natural Sciences
Spatial Coverage (17.543 LON, -35.125 LAT); Southern Cape Basin