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Due to the high sensitivity of southern Africa to climate change, a reliable understanding of its hydrological system is crucial. Recent studies of the regional climatic system have revealed a highly complex interplay of forcing factors on precipitation regimes. This includes the influence of the tropical easterlies, the strength of the southern hemispheric westerlies as well as sea surface temperatures along the coast of the subcontinent. However, very few marine records have been available in order to study the coupling of marine and atmospheric circulation systems. Here we present results from a marine sediment core, recovered in shallow waters off the Gouritz River mouth on the south coast of South Africa. Core GeoB18308-1 allows a closer view of the last ∼ 4 kyr. Climate sensitive organic proxies, like the distribution and isotopic composition of plant-wax lipids as well as indicators for sea surface temperatures and soil input, give information on oceanographic and hydrologic changes during the recorded time period. Moreover, the micropaleontology, mineralogical and elemental composition of the sediments reflect the variability of the terrigenous input to the core site. The combination of down-core sediment signatures and a catchment-wide provenance study indicate that the Little Ice Age ( ∼ 300–650 cal yr BP) was characterized by climatic conditions favorable to torrential flood events. The Medieval Climate Anomaly ( ∼ 950–650 cal yr BP) is expressed by lower sea surface temperatures in the Mossel Bay area and humid conditions in the Gouritz River catchment. These new results suggest that the coincidence of humid conditions and cooler sea surface temperatures along the south coast of South Africa resulted from a strengthened and more southerly anticyclonic circulation. Most probably, the transport of moisture from the Indian Ocean by strong subtropical easterlies was coupled with Agulhas Bank upwelling pulses, which were initiated by an increase in Agulhas Current strength.

This research cruise with the RV Meteor into South African waters was realized in December 2013. The cruise was embedded in the German South African cooperation within the framework of the SPACES program and provided a very important extension and contribution to the works planned in the RAIN (Regional Archives for Integrated Investigations) and WCLL (Wild Coast Living Laboratory) projects as well as a valuable additional data set to the GENUS-II project. The focus of the cruise was on the origin and dynamics of the Agulhas current and its interplay with estuarine systems along South Africa's east coast, and the dynamics of ESACW and SACW and its impact on the OMZ in the northern Benguela upwelling system. The focus of the geological work was on the investigation of paleo lagoons off Mossel Bay and Durban. A strong focus was put on training and capacity building activities in physical, biological, biogeochemical and geological marine research. A total of 15 berths were provided for post-graduate or PhD students and young scientists to learn state of the art methods in marine science. The joint work at sea of ten South African and five German trainees is seen as an important element to foster intercultural exchange and provide a common basis for potential future cooperation. To reach the scientific goals of the cruise we worked up 44 stations along the Southern African coast and 4 south of Madagascar. We realised 30 CTD casts, 16 vertical and 26 towed multi net hauls, and 18 Ring Trawls. A total of 10 drifters and floats were deployed around Madagascar to investigate the currents in the Mozambique channel. Parasound was used along a track of 62 km to map sea bottom structure off Durban and Mossel Bay and search for potential sites to deploy Gravity Corer and Vibro Corer at a total of 11 stations. Underway measurements could be performed on pCO2 distribution. Lectures were hold regularly on different topics and trainees were supervised to prepare the cruise report., METEOR-Berichte