How topography brakes the Antarctic Circumpolar Current. This project aims to observe and simulate the mechanisms that slow the Antarctic Circumpolar Current. The Southern Ocean winds have increased over the last two decades while the transport of the world’s largest current remains steady or slightly decreasing. A possible explanation is negative feedback mechanisms between the winds and transport of the Antarctic Circumpolar Current. This project will observe how eddies carry momentum from the ....How topography brakes the Antarctic Circumpolar Current. This project aims to observe and simulate the mechanisms that slow the Antarctic Circumpolar Current. The Southern Ocean winds have increased over the last two decades while the transport of the world’s largest current remains steady or slightly decreasing. A possible explanation is negative feedback mechanisms between the winds and transport of the Antarctic Circumpolar Current. This project will observe how eddies carry momentum from the wind down to the sea floor and accelerate the deep currents that drag against the rough bottom to put the brakes on this current. Since this current affects Australian rainfall patterns and agricultural output, findings could inform public policy.Read moreRead less
Coupling tropical cyclone and climate physics with ocean waves. It is argued that without accounting for the wave effects directly, the physics of large-scale air-sea interactions is inaccurate and incomplete. The project will introduce explicit coupling of large-scale atmospheric and oceanic phenomena with the physics of surface waves which should lead to improved predictions of tropical cyclones and climate.
Observations of remarkable eastward flows in the South Indian Ocean. The Indian Ocean drives much of the variability of Australian weather and rainfall and is rapidly evolving. Innovative new observations of remarkable eastward flows in the South Indian Ocean will be combined with models to understand these circulations in a region that has significant economic value for Australia.
Advancing dynamical understanding in the East Australian Current: Optimising the ocean observation and prediction effort. The East Australian Current is a highly dynamic system, thus is very difficult to observe, measure and predict. Our aim is to advance the dynamical understanding of this complex system and to quantify the value of specific observations in improving ocean state-estimates. State-estimates are critical for robust ocean predictions in a region that is warming faster than anywhere ....Advancing dynamical understanding in the East Australian Current: Optimising the ocean observation and prediction effort. The East Australian Current is a highly dynamic system, thus is very difficult to observe, measure and predict. Our aim is to advance the dynamical understanding of this complex system and to quantify the value of specific observations in improving ocean state-estimates. State-estimates are critical for robust ocean predictions in a region that is warming faster than anywhere else on the planet. This project will integrate innovative numerical modeling techniques with a state-of-the-art ocean observing system. The expected outcomes will guide future ocean observing efforts; maximising impact while reducing cost. The results will be readily applicable to analogous systems around the world and our team is well placed to implement them internationally.Read moreRead less
An ensemble approach to studying the ocean's role in climate change. Using a newly-developed ocean model that harnesses the power of graphical processing units (GPUs) instead of the common central processing units (CPUs) we can run global ocean simulations at 1/50th the cost. Utilising this speed up, we aim to pioneer a modelling framework to perform ensembles of eddy-resolving global ocean simulations under various climate-change scenarios. This ensemble approach will enable us to separate the ....An ensemble approach to studying the ocean's role in climate change. Using a newly-developed ocean model that harnesses the power of graphical processing units (GPUs) instead of the common central processing units (CPUs) we can run global ocean simulations at 1/50th the cost. Utilising this speed up, we aim to pioneer a modelling framework to perform ensembles of eddy-resolving global ocean simulations under various climate-change scenarios. This ensemble approach will enable us to separate the changes we see in future projections that are due to climate change from the changes that occur in the due to the natural variations of the climate system. The project's outcomes will increase our confidence in future climate change projections, including ocean heat uptake, and sea level rise.Read moreRead less
A Laboratory Study of Ocean-Atmosphere Coupling in the Antarctic Circumpolar Wave. A laboratory model of the southern hemisphere mid-latitude ocean-atmosphere system will be used to investigate the dynamics of ocean-atmosphere coupling contributing to the Antarctic Circumpolar Wave (ACW). The ACW is a recently discovered multi-year climate oscillation which has considerable effect on Australian and New Zealand precipitation. This will be the first laboratory model to include global scale ocean-a ....A Laboratory Study of Ocean-Atmosphere Coupling in the Antarctic Circumpolar Wave. A laboratory model of the southern hemisphere mid-latitude ocean-atmosphere system will be used to investigate the dynamics of ocean-atmosphere coupling contributing to the Antarctic Circumpolar Wave (ACW). The ACW is a recently discovered multi-year climate oscillation which has considerable effect on Australian and New Zealand precipitation. This will be the first laboratory model to include global scale ocean-atmosphere processes, and will be used to test proposed mechanisms for the driving of the climate oscillation that is attributed to the ACW. The project will provide knowledge required for improved computational modelling and climate predictions.
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Causes of Enhanced Warming of the Southern Ocean. The Southern Ocean is critical to the global climate system in general, and Australian climate in particular. However, the Southern Ocean is poorly understood, poorly observed and poorly modelled by global climate models. The response of the Southern Ocean to increases in wind forcing (due to the ozone hole and global warming) will be examined. Climate impacts such as Australian rainfall trends, potential instability of the West Antarctic Ice She ....Causes of Enhanced Warming of the Southern Ocean. The Southern Ocean is critical to the global climate system in general, and Australian climate in particular. However, the Southern Ocean is poorly understood, poorly observed and poorly modelled by global climate models. The response of the Southern Ocean to increases in wind forcing (due to the ozone hole and global warming) will be examined. Climate impacts such as Australian rainfall trends, potential instability of the West Antarctic Ice Sheet and changes to the global overturning circulation will be quantified. Understanding these impacts will help to manage Australia's water resources and to predict the future Southern Ocean circulation.Read moreRead less
Sensitivity and Change in the Global Ocean Overturning. The dynamics of the global, deep overturning circulation in the oceans and the way this adjusts to increasing greenhouse forcing will be examined in order to improve our conceptual knowledge of the oceans and the accuracy of climate models. By understanding how the ocean responds to changing surface heat and freshwater fluxes, and particularly the global role of rapid changes in high-latitude seas, we aim to help refine estimates of climate ....Sensitivity and Change in the Global Ocean Overturning. The dynamics of the global, deep overturning circulation in the oceans and the way this adjusts to increasing greenhouse forcing will be examined in order to improve our conceptual knowledge of the oceans and the accuracy of climate models. By understanding how the ocean responds to changing surface heat and freshwater fluxes, and particularly the global role of rapid changes in high-latitude seas, we aim to help refine estimates of climate response times and the warming expected for a given increase in atmospheric greenhouse gases. These two important characteristics of the climate system underlie climate change policy decisions.Read moreRead less
Nonhydrostatic waves and instabilities in rotating fluids. This project addresses a fundamental gap in our understanding of the ocean circulation. The benefits of the program will be to improve the way we model and predict the ocean circulation and the response of the ocean to climate change. The project will thereby assist National Research Priorities on global change and link with a major new ANU Marine Science Strategic Initiative.
Quantifying the role of the Southern Ocean for anthropogenic CO2 uptake. Carbon dioxide (CO2) is the most important greenhouse gas contributing to global warming and climate change. Climate change is likely to have dramatic economic and environmental consequences for Australia. Knowledge and understanding of the complex carbon cycle is fundamental for predicting future atmospheric CO2 levels and managing climate change. The aim of the work proposed here is to quantify and improve our understan ....Quantifying the role of the Southern Ocean for anthropogenic CO2 uptake. Carbon dioxide (CO2) is the most important greenhouse gas contributing to global warming and climate change. Climate change is likely to have dramatic economic and environmental consequences for Australia. Knowledge and understanding of the complex carbon cycle is fundamental for predicting future atmospheric CO2 levels and managing climate change. The aim of the work proposed here is to quantify and improve our understanding of the oceans role in controlling atmospheric CO2 levels. This will be done by combining modeling and observational expertise among UNSW and CSIRO (Marine Research) researchers. Our work will be the first to assess the extent of which the Southern Ocean (and Australian waters) acts as a carbon sink. This will reduce modeling uncertainties in predicting future atmospheric CO2 levels and will also be valuable to the federal government in future international negotiations on climate change.Read moreRead less