Research Projects

The Antarctic Circumpolar Current (ACC) is an important component of the Southern Ocean, the planet’s strongest and only circumpolar current, linking the Pacific, Atlantic, and Indian Oceans. The ACC and its associated wind systems play a vital role in the global climate system by insulating the Antarctic ice sheet from warmer northern waters and facilitating the exchange of water masses such as Circumpolar Deep Water (CDW) between ocean basins. Despite its significance, the behavior of the ACC and related water masses under warmer-than-present climate conditions remains poorly understood, limiting our knowledge of their broader climatic and ecological impacts. To address this, I will utilize newly recovered marine sediment cores from IODP Site U1541 in the Pacific sector of the Southern Ocean, an exceptional archive of oceanographic conditions during the warm Pliocene epoch. My approach combines multiple paleoceanographic proxies: (i) I will examine the abundance and assemblage variations of planktic foraminifera and ostracods, both sensitive indicators of water column and bottom-water conditions, respectively. These microfossils respond to changes in temperature, salinity, oxygenation, and nutrient availability, key factors driven by climatic shifts. (ii) I will perform stable isotope (δ¹⁸O, δ¹³C) and trace element (Mg/Ca) analyses on planktic foraminifera and Mg/Ca on ostracod carapace to reconstruct sea surface and bottom-water temperatures and infer salinity variations. These data will be integrated with my previously published records from benthic foraminifera (including isotopic and Mg/Ca data) to better understand changes in CDW formation, a process tightly linked to ice sheet dynamics in the Antarctic hinterland. This multi-proxy approach will advance our understanding of glacial-interglacial variability during warmer baseline climates and may reveal links to low-latitude climate systems, such as monsoon behavior. Ultimately, the study aims to identify key ocean-atmosphere teleconnections that shaped global climate variability in the Early Pliocene.