Past intermediate and deep ocean circulation during sustained periods of warmth

Project Description:

The ocean is absorbing much of the heat and carbon dioxide emissions related to human caused climate change, but the long-term impacts on heat transport, carbon cycling and deep ocean circulation are poorly understood. Looking at past warm periods such as the Last Interglacial (125,000 years ago) and other “Super-Interglacials” where global temperatures are estimated to be 0.5 to 1.5°C warmer than today may provide insight into how the ocean accommodates heat and carbon. This project will use a suite of locations in the Atlantic and/or Pacific to characterize and map intermediate and deep water masses and ocean circulation.

This project necessitates a multi-proxy approach including stable isotopes (d13C, d18O), minor (Mg/Ca, temperature) and trace elements (B/Ca, [CO32-]) and trace isotopes (ENd). The project can be tailored to focus on regional (e.g. North Atlantic, Southern Ocean) or basin-wide reconstructions of ocean circulation depending on the research interests of the student.

Policy Impact of Research:

As the ocean is a large part of the climate system, being able to constrain the ocean’s long-term response to future climate change on a variety of time scales has significant economic and societal impacts.

Research Relating to this Project:

1. Active Pacific meridional overturning circulation (PMOC) during the warm Pliocene
2. The evolution of the equatorial thermocline and the early Pliocene El Padre mean state
3. Increased ventilation of Antarctic deep water during the warm mid-Pliocene