1a) 2, the dynamics of which have been suggested to impact global climate variability over multiple timescales 2, 3.
Among the characteristic features of the Southern Ocean sector of the Indian Ocean are the distinct ocean fronts and associated water masses (Fig. It interconnects the Atlantic, Pacific and Indian Ocean basins, and is therefore important for transmitting climate signals from one region to another 1. The Southern Ocean plays a fundamental role in global climate. We conclude that the biological pump was more efficient and strengthened during glacial periods, which could partly account for the reported reduction in atmospheric carbon dioxide concentrations. Alkenone and coccolith abundances, in combination with diatom and organic carbon records indicate high glacial export productivity. We identify a strong glacial-interglacial variability in sea surface temperature and productivity associated with subtropical front migration over the Agulhas Plateau, as well as shorter-term high frequency variability aligned with variations in high latitude insolation. Here we analyse a sedimentary record from the Agulhas Plateau, located close to the modern position of the subtropical front and use alkenones and coccolith assemblages to reconstruct oceanographic conditions over the past 300,000 years. In the southern Indian Ocean, the position of the subtropical front – the boundary between colder, fresher waters to the south and warmer, saltier waters to the north – has a strong influence on the upper ocean hydrodynamics and biogeochemistry. Strong glacial-interglacial variability in upper ocean hydrodynamics, biogeochemistry, and productivity in the southern Indian Ocean
0 kommentar(er)
