Is there a climatic tipping point for Antarctic Bottom Water formation? Antarctic Bottom Water plays an important role in global ocean circulation and climate and yet its formation is also highly sensitive to climate change. This project will analyse new seafloor, core and water samples from the understudied Cape Darnley, East Antarctica, collected on a voyage in early 2022. This new data will be used in combination with an improved high resolution regional ocean model, to understand modern and ....Is there a climatic tipping point for Antarctic Bottom Water formation? Antarctic Bottom Water plays an important role in global ocean circulation and climate and yet its formation is also highly sensitive to climate change. This project will analyse new seafloor, core and water samples from the understudied Cape Darnley, East Antarctica, collected on a voyage in early 2022. This new data will be used in combination with an improved high resolution regional ocean model, to understand modern and past Antarctic Bottom Water formation under different climate states (warmer and colder than present), to determine if there are climate tipping points for the shut down of Antarctic Bottom Water formation. The anticipated benefits include a better understanding of future climate change on this important water mass.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
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.
Robotic investigation of water optical properties in the Southern Ocean. The project aims to improve our understanding of light–matter interactions in the waters of the Southern Ocean (SO), in particular the role of phytoplankton and associated material of biological origin. Phytoplankton are the energy source for the food web and a critical component of carbon cycling in the SO. However, their dynamics in the SO cannot be quantified using satellite observations because bio-optical data processi ....Robotic investigation of water optical properties in the Southern Ocean. The project aims to improve our understanding of light–matter interactions in the waters of the Southern Ocean (SO), in particular the role of phytoplankton and associated material of biological origin. Phytoplankton are the energy source for the food web and a critical component of carbon cycling in the SO. However, their dynamics in the SO cannot be quantified using satellite observations because bio-optical data processing algorithms perform poorly due to a lack of field data. This project seeks to remedy this by improving understanding of SO bio-optics, and by providing novel algorithms of known uncertainty, based on in situ data.Read moreRead less
The role of Eastern Antarctic polynyas in global ocean circulation. This project aims to study Antarctic polynyas, an important, but poorly observed marine habitat, which profoundly influence the global climate. The major water masses of the world's oceans are formed there, making a large contribution to the ocean heat and carbon dioxide uptake. This study will collect data on ocean properties to 2000m from polynyas in eastern Antarctica throughout the Antarctic winter. The outcomes will be the ....The role of Eastern Antarctic polynyas in global ocean circulation. This project aims to study Antarctic polynyas, an important, but poorly observed marine habitat, which profoundly influence the global climate. The major water masses of the world's oceans are formed there, making a large contribution to the ocean heat and carbon dioxide uptake. This study will collect data on ocean properties to 2000m from polynyas in eastern Antarctica throughout the Antarctic winter. The outcomes will be the provision of data of critical importance to oceanographic and climate studies.Read moreRead less
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
Deciphering strategies polar phytoplankton employ to lessen iron limitation. The Southern Ocean is of global importance. It comprises one-third of the global ocean by area and disproportionately absorbs two-thirds of anthropogenic ocean heat and half of anthropogenic carbon dioxide (CO2) emissions even though phytoplankton in this region are chronically iron-limited. This project aims to understand why copper uptake by phytoplankton lessens the effects of iron limitation and how copper substitut ....Deciphering strategies polar phytoplankton employ to lessen iron limitation. The Southern Ocean is of global importance. It comprises one-third of the global ocean by area and disproportionately absorbs two-thirds of anthropogenic ocean heat and half of anthropogenic carbon dioxide (CO2) emissions even though phytoplankton in this region are chronically iron-limited. This project aims to understand why copper uptake by phytoplankton lessens the effects of iron limitation and how copper substitutes for iron. This knowledge is critical for evaluating the impacts and feedbacks between iron and copper in regulating Southern Ocean productivity and ultimately its ability to drawdown atmospheric CO2. The results from this project will facilitate the development of improved ecosystem models and conservation tools.Read moreRead less
Hot iron: Are submarine volcanoes important for Southern Ocean iron supply? The scarcity of iron limits biological productivity and carbon uptake in the nutrient rich waters of the Southern Ocean. This project will explore for the first time the role of undersea "hot spot" volcanoes in supplying iron to surface waters, thus linking the solid earth and the biosphere. The project will measure iron abundance, reactivity and nutritional value in buoyant plumes emanating from vents near Heard/McDonal ....Hot iron: Are submarine volcanoes important for Southern Ocean iron supply? The scarcity of iron limits biological productivity and carbon uptake in the nutrient rich waters of the Southern Ocean. This project will explore for the first time the role of undersea "hot spot" volcanoes in supplying iron to surface waters, thus linking the solid earth and the biosphere. The project will measure iron abundance, reactivity and nutritional value in buoyant plumes emanating from vents near Heard/McDonald Islands, Australia's only active volcanoes. The project aims to estimate the hydrothermal contribution to regional biological productivity and extrapolate to the whole Southern Ocean. Successful outcomes will benefit Australia by identifying iron sources that govern productivity and carbon uptake of an economically important ecosystem.Read moreRead less
How iron is cycled in Southern Ocean waters. This project aims to probe the Southern Ocean phytoplankton’s ability to take up and retain iron, using iron isotope tracer techniques. The Southern Ocean regulates Earth's climate, but the supply of iron to Southern Ocean surface waters is low, restricting the ability of phytoplankton to flourish and draw down carbon dioxide. The results are expected to reveal survival strategies of phytoplankton in this iron-poor environment and their potential abil ....How iron is cycled in Southern Ocean waters. This project aims to probe the Southern Ocean phytoplankton’s ability to take up and retain iron, using iron isotope tracer techniques. The Southern Ocean regulates Earth's climate, but the supply of iron to Southern Ocean surface waters is low, restricting the ability of phytoplankton to flourish and draw down carbon dioxide. The results are expected to reveal survival strategies of phytoplankton in this iron-poor environment and their potential ability to adapt to environmental change. This knowledge could be used to develop models to manage this climate-sensitive region.Read moreRead less
Understanding spread in sea level rise projections. This project aims to investigate changes in water properties and ocean circulation mechanisms leading to intermodel spread in sea-level projections. Sea-level rise projections for this 21st century largely disagree in magnitude and spatial changes between climate models, particularly in hotspots. The expected outcomes will contribute towards more rigorous constraints on the likelihood of future warming and sea-level rise projections, and are al ....Understanding spread in sea level rise projections. This project aims to investigate changes in water properties and ocean circulation mechanisms leading to intermodel spread in sea-level projections. Sea-level rise projections for this 21st century largely disagree in magnitude and spatial changes between climate models, particularly in hotspots. The expected outcomes will contribute towards more rigorous constraints on the likelihood of future warming and sea-level rise projections, and are aligned with scientific deliverables required to address key questions in support of Australia’s climate change policy. They are also aligned with international scientific deliverables in support of the World Climate Research Programme Grand Challenge on Regional Sea Level Change and Coastal Impacts.Read moreRead less