Cardiff University

The major focus of the CU Palaeoclimate Research Group within the GATEWAYS programme is to quantitatively reconstruct key variables via proxy measurements within marine sediment cores that allow the long-term dynamics of the Agulhas Current and deep ocean circulation to be assessed. The work aims at understanding the connectivity between Indian-Atlantic gateway dynamics, inter-ocean buoyancy transports and Atlantic Meridional Overturning Circulation (AMOC) sensitivity. Reconstructions focus on surface and deep ocean palaeo-proxies from sediment cores in the Indian-Atlantic ocean gateway during climate intervals of past accelerated change.  These reconstructions provide a test bed for model simulations carried out by collaborating partners that assess the dynamics of the Current in the past and its impact on the AMOC. The data generated by the UC team are available to compare with other palaeoclimate reconstructions generated by other partners in the network project so as to make a comprehensive assessment of possible impact of Agulhas Current buoyancy transports on South African climate evolution, AMOC variability and far-field climate change.

Analytical methodologies comprise stable isotope and geochemical analytical protocols on planktonic and benthic foraminifera: d18O, d13C, Mg/Ca, Cd/Ca. Radiogenic isotopes and sedimentological parameters are analysed that are sensitive to water mass advection and near-bottom flow speed: 230Pa/231Th, sortable silt mean grain size (SS).

Sediment core material is made available for complementary proxy measurements across the network portfolio, such as Pa/Th with UAB; micropalaeontological indices such as the "Agulhas Leakage Fauna" and "Subtropical Front" index in collaboration with VUA; deuterium analysis (dD) in collaboration with NIOZ; Planktonic foraminiferal proxy data to document surface water properties in the network working area in collaboration with UAB.

The data generated by the CU team focus on assessing Indian-Atlantic gateway dynamics, inter-ocean buoyancy transports and AMOC sensitivity.  This involves the generation/integration of relevant surface and deep ocean proxy measurements to evaluate the dynamical linking between gateway circulation, salt leakage events and transient AMOC shifts (cross-linked with partners NIOZ, VUA and UAB).   Ocean numerical modelling is employed in collaboration with network partners (AWI and IFM-GEOMAR) with palaeo-climatic forcing to constrain deep-circulation variability and verify interpretation of palaeo-data distribution.


Partner Profile

The School of Earth and Ocean Sciences at Cardiff University is a dynamic and successful is a multi-disciplinary centre devoted to research in the Ocean and Earth sciences. It currently has a staff of more than 55 academics and through its Post-graduate School provides training and a high level of support for over 60 Early-stage researchers. The Schools Palaeoclimate Research Group is a leading team investigating the causes and scales of climate variability and the sensitivity of marine and terrestrial environments to naturally occurring climatic perturbations during the recent (historical) and geologic past.

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