Dynamics of pacific antarctic circumpolar current (dynapacc)
May-july 2019
Joides Resolution, Punta Arenas, Chile. Source: C. Basak
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Expedition objective: The Antarctic Circumpolar Current (ACC) is a mighty zonal current that connects the Pacific, Atlantic, and Indian Oceans. Understanding ACC behavior through time is critical to develop a holistic understanding of how oceans play a role in global climate. In this expedition, sediment cores were collected from the south central Pacific and off the coast of Chile to study Plio-Pleistocene climate history.
Coring to reconstruct ocean circulation and carbon dioxide across 2 seas: Crocca-2s
November-December 2018
RV Thomas G Thompson. Photo source: University of Washington
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Expedition objective: For the last 800 thousands of years, Earth's climate witnessed a persistent fluctuation of CO2 of about 80-100 ppmv between cold and warm intervals (i.e. glacial-interglacial). It is generally agreed that the ocean must have played a dominant role in modulating atmospheric CO2 over glacial-interglacial (i.e. thousand years) time scales, since it is the single largest reservoir of CO2 capable of equilibrating with the atmosphere within 1000 years. One goal of this expedition was to collect piston cores from the Indian Ocean to bring back sediment that would allow us to study ocean's carbon storage, changes in deep ocean circulation, and how these aspects of deep ocean changed during past cold and warm intervals. Seawater, surface sediments, and porewater samples were also collected during this expedition to ground-truth proxies so that those proxies can be used on down-core sediments to reliably interpret past climate signals.
