Ocean Acidification in a Rapidly Increasing CO2 World. Carbon dioxide not only acts as a greenhouse gas but is being dissolved at increasing rates into the surface waters of the world's oceans, causing ocean acidity. We will examine how the rapidly increasing trend towards acidity in the oceans surrounding Australia is effecting the ability of marine organisms to calcify and determine the rate at which the world's ocean sink for CO2 is being reduced. New constraints will be placed on the critica ....Ocean Acidification in a Rapidly Increasing CO2 World. Carbon dioxide not only acts as a greenhouse gas but is being dissolved at increasing rates into the surface waters of the world's oceans, causing ocean acidity. We will examine how the rapidly increasing trend towards acidity in the oceans surrounding Australia is effecting the ability of marine organisms to calcify and determine the rate at which the world's ocean sink for CO2 is being reduced. New constraints will be placed on the critical threshold limits of CO2 emissions for sustainable calcification in both shallow tropical and deep-water marine ecosystems of the Southern Oceans.Read moreRead less
Keystone microbes and planktonic guilds in Australia's oceans. This project aims to unveil the ocean’s hidden sentinels, “keystone microbes” that underpin precious ecosystem services, and which can be used to monitor and model changes in ocean function. Marine microbes account for 90 per cent of oceanic biomass and every litre of seawater contains ~20,000 different species, but it is not known which species control ocean health and productivity. This project intends to provide definitive evidenc ....Keystone microbes and planktonic guilds in Australia's oceans. This project aims to unveil the ocean’s hidden sentinels, “keystone microbes” that underpin precious ecosystem services, and which can be used to monitor and model changes in ocean function. Marine microbes account for 90 per cent of oceanic biomass and every litre of seawater contains ~20,000 different species, but it is not known which species control ocean health and productivity. This project intends to provide definitive evidence of these keystones’ cellular level biogeochemical and metabolic capacity. Ultimately, this knowledge is expected to predict the resilience of ocean ecosystems and their response to change. The capacity to predict their dynamics will help provide investment clarity and increase healthy outcomes from activities involving human-ocean interactions such as recreation, food production and tourism.Read moreRead less
Holding coral reefs together with soluble cement. This project aims to characterise and understand cement formation in coral reefs. Coral reefs are constructed by cementing together aragonite building blocks made by corals. The main cementing agent is high-magnesium calcite, the most soluble carbonate mineral and susceptible to ocean acidification. High-magnesium calcite cements are best developed on the high energy margins of coral reefs. This project will quantify how crustose coralline algae ....Holding coral reefs together with soluble cement. This project aims to characterise and understand cement formation in coral reefs. Coral reefs are constructed by cementing together aragonite building blocks made by corals. The main cementing agent is high-magnesium calcite, the most soluble carbonate mineral and susceptible to ocean acidification. High-magnesium calcite cements are best developed on the high energy margins of coral reefs. This project will quantify how crustose coralline algae produces high-magnesium calcite and controls the dissolution and reprecipitation of high-magnesium cements. This project intends to quantify rates of reef cementation, susceptibility to ocean acidification and warming, and possible mitigating effects of alkalinity addition.Read moreRead less
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.
From The Ocean Depths To Abrupt Climate Change - Missing Processes In The Global Overturning Circulation. The overturning circulation of the oceans is a driver of large and surprisingly abrupt climate shifts. We aim to understand the factors that control the rate of overturning, and whether it might soon slow down or cease owing to global warming. We also aim to resolve one of the biggest conundrums in oceanography by reconciling theoretical and measured rates of mixing in the deep ocean. Improv ....From The Ocean Depths To Abrupt Climate Change - Missing Processes In The Global Overturning Circulation. The overturning circulation of the oceans is a driver of large and surprisingly abrupt climate shifts. We aim to understand the factors that control the rate of overturning, and whether it might soon slow down or cease owing to global warming. We also aim to resolve one of the biggest conundrums in oceanography by reconciling theoretical and measured rates of mixing in the deep ocean. Improved knowledge of deep ocean dynamics, particularly in the Southern Ocean, will help us gauge the likely nature and pace of imminent climate changes in the Australian region, an essential step in assessing the impacts on water resources, ecosystems, agriculture, and energy demands. The research will add to a major new initiative in marine science at ANU.Read moreRead less
Mixing and dissipation in the ocean: Processes for the next generation of climate models. The circulation of the oceans is a crucial factor in governing the variability and long-term change in the earth's climate. A major weakness in current ocean and climate models is a lack of knowledge of energy flow within the ocean. This project will examine the nature and role of eddy interactions with the ocean boundaries, which is a critical question for future development of more accurate high-resolutio ....Mixing and dissipation in the ocean: Processes for the next generation of climate models. The circulation of the oceans is a crucial factor in governing the variability and long-term change in the earth's climate. A major weakness in current ocean and climate models is a lack of knowledge of energy flow within the ocean. This project will examine the nature and role of eddy interactions with the ocean boundaries, which is a critical question for future development of more accurate high-resolution ocean models and improved climate predictions.Read moreRead less
Unraveling ocean mixing and air-sea forcing along the Indo-Pacific exchange. This project aims to collect unprecedented observations and develop high resolution model simulations to examine changes in the Indonesian Throughflow (ITF) north of Australia. This project expects to develop new knowledge of ocean-atmosphere interactions along the path of the ITF from the Pacific to the Indian Ocean, which are the powerhouse that drives changes in winds and rainfall around Australia and the entire Indo ....Unraveling ocean mixing and air-sea forcing along the Indo-Pacific exchange. This project aims to collect unprecedented observations and develop high resolution model simulations to examine changes in the Indonesian Throughflow (ITF) north of Australia. This project expects to develop new knowledge of ocean-atmosphere interactions along the path of the ITF from the Pacific to the Indian Ocean, which are the powerhouse that drives changes in winds and rainfall around Australia and the entire Indo-Pacific region. Expected outcomes include a 1000-fold increase in the observations of mixing in the Indonesian seas and new understanding of the ocean-atmosphere processes that control water property change along the ITF. This should lead to strong improvement in the skill of climate forecast models in the Australian region.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.