Dynamics of physical and biological systems of the Prince Edward Islands in a changing climate

Sub-Antarctic islands are classified as isolated, hostile, impoverished regions, in which the terrestrial and marine ecosystems are relatively simple and extremely sensitive to perturbations. They provide an ideal ecological laboratory for studying how organisms, ecological processes and ecosystems respond to a changing ocean climate in the Southern Ocean. 1hese islands are characterised by large populations of top predators and subsequently any changes in the oceanographic frontal dynamics associated with the Antarctic Circumpolar Current, either in the vicinity of these islands or further afield, may have strong implications on their foraging behaviour. The relatively easy accessibility of the Prince Edward Islands from South Africa and their location between the main frontal systems bordering the Antarctic Circumpolar Current enable high-resolution synoptic field studies to be undertaken. Such studies have provided information on the impact changes in the large-scale ocean dynamics have on the local marine ecosystems

Madagascar corals track sea surface temperature variability in the Agulhas Current core region over the past 334 years

The Agulhas Current (AC) is the strongest western boundary current in the Southern Hemisphere and is key for weather and climate patterns, both regionally and globally. Its heat transfer into both the midlatitude South Indian Ocean and South Atlantic is of global significance. A new composite coral record (Ifaty and Tulear massive Porites corals), is linked to historical AC sea surface temperature (SST) instrumental data, showing robust correlations. The composite coral SST data start in 1660 and comprise 200 years more than the AC instrumental record. Numerical modelling exhibits that this new coral derived SST record is representative for the wider core region of the AC. AC SSTs variabilities show distinct cooling through the Little Ice Age and warming during the late 18th, 19th and 20th century, with significant decadal variability superimposed. Furthermore, the AC SSTs are teleconnected with the broad southern Indian and Atlantic Oceans, showing that the AC system is pivotal for inter-ocean heat exchange south of Africa