Research program: Mechanisms and attribution of past and future ocean circulation change
The ocean currents have a powerful influence on our climate. These currents govern the ocean storage of carbon and heat, and have already partially mitigated the effects of global warming. Any change to these currents can abruptly affect global climate as shown in our geological past.
This project aims to investigate these ocean processes, revealing how wind stress, heat content and salinity affect ocean currents and how the ocean in turn couples with atmospheric processes to form our climate. The project will also examine biogeochemical processes and how these interact with ocean currents to control the carbon cycle in the ocean. The research goals of the Oceans Research Program can be divided into five (overlapping) themes:
Detection and Attribution of Change in the Oceans
Changing ocean indicators, such as heat content, salinity and oxygen, help us to refine our understanding of changes in climate, and consequent impacts on the ocean circulation. Using a combination of ocean observations and model simulations we examine the individual processes that have contributed to recent change in the ocean.
A High Resolution Ocean-Climate Model for Australia
We are helping to develop a high resolution ocean model which will contribute to Australia’s next generation climate model. The model is based on MOM5 and is ¼° in horizontal resolution, giving us the ability to permit ocean eddies.
The Ocean’s Meridional Overturning Circulation
The Meridional Overturning Circulation (or MOC) describes the sinking of cold, dense water near the poles, which upwell back to the surface in the interior of the ocean. This circulation controls the earth’s climate on long timescales, and we aim to reconcile our understanding of the theory these currents with observations and model analyses.
Carbon Cycle Feedbacks
The ocean absorbs anthropogenic carbon through a mixture of physical transport processes and biological uptake of CO2. We examine the processes that control carbon uptake, with specific focus on the Southern Ocean and the role of small-scale dynamics.
Oceanic Mesoscale Eddies and Their Impact on the Large Scale Circulation
Ocean eddies dominate the circulation on small scales (less than 100km), but their impact on the large scale circulation remains unclear. We use numerical models of the ocean circulation to quantify how eddies and other small-scale or time-dependent features alter the transport of heat and other tracers.