The global ocean is currently absorbing much of the heat and CO2 emissions due to human-induced global warming, but the long-term impacts of this absorption on climate and ocean circulation remain poorly understood. Projections for 21st-century climate, produced for the Intergovernmental Panel on Climate Change, suggest that global warming will result in weaker global overturning circulation, increasing upper ocean stratification, and anoxia. However, recent findings suggested that a North Pacific deep-water (NPDW) formation and a Pacific Meridional Overturning Circulation (PMOC) were present at times during the warm Pliocene (a pseudo-analogue for the current global warming). In this project, along with climate modelers, geochemists, and astrochonologists, we will test this hypothesis and will trace the regional distribution of ocean ventilation. Additionally, we aim to refine the use of redox, temperature, and productivity proxies both in bulk sediments and foraminifera for reconstructing Pliocene Ocean ventilation, nutrient availability, and water mixing. If convincing evidence for a PMOC is found, it will require a substantial revision of our understanding of the Pliocene climate, as well as of the long-term response of the global ocean-atmosphere system to future climate change.

Funding: 

NSF Collaborative Research: Tracing Pacific Ocean circulation and ventilation during the warm Pliocene Epoch

Team

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