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
Winter temperature and salinity profile measurements in the Southern Ocean using elephant seals as ocean sampling platforms. As a result of the paucity of winter data in the Southern Ocean, sophisticated ocean models such as the GFDL MOM are hampered in their ability to properly represent the complex processes in the Antarctic sea ice zone. Elephant seals forage in the Southern Ocean throughout winter, and traverse the water column between 0 and 800 metres many times each day, providing an oppo ....Winter temperature and salinity profile measurements in the Southern Ocean using elephant seals as ocean sampling platforms. As a result of the paucity of winter data in the Southern Ocean, sophisticated ocean models such as the GFDL MOM are hampered in their ability to properly represent the complex processes in the Antarctic sea ice zone. Elephant seals forage in the Southern Ocean throughout winter, and traverse the water column between 0 and 800 metres many times each day, providing an opportunity to collect profiles of temperature and salinity. The resulting data will contribute to oceanographic studies of water mass formation and frontal variability, including comparisons with historical data and assimilation into a complex ocean model.Read moreRead less
Active Ice-Shelf Rift Systems on the Amery Ice Shelf, East Antarctica. Our work will inform the public on how the Antarctic might contribute to global sea level rise, e.g., are current iceberg production rates accelerating and causing inland ice to flow into the sea more rapidly? Furthermore, a greater understanding of the important Earth systems, including the ocean-ice-atmosphere system, is important to a society contemplating the responsibilities of stewardship of the planet as we move into t ....Active Ice-Shelf Rift Systems on the Amery Ice Shelf, East Antarctica. Our work will inform the public on how the Antarctic might contribute to global sea level rise, e.g., are current iceberg production rates accelerating and causing inland ice to flow into the sea more rapidly? Furthermore, a greater understanding of the important Earth systems, including the ocean-ice-atmosphere system, is important to a society contemplating the responsibilities of stewardship of the planet as we move into the era of potentially profound effects from global climate change.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
Quantifying sea-level trends and extremes along Australia's coastal margin. Multi-decadal changes in sea-level, and sea-level extremes, cannot be well quantified along most global coastlines, including Australia's, because the high spatial variability of sea-level is under-sampled by the sparse set of long, high quality tide gauge records. Satellite altimetry provides an alternative data source with greater spatial sampling, yet experiences contamination from land within tens of kilometres from ....Quantifying sea-level trends and extremes along Australia's coastal margin. Multi-decadal changes in sea-level, and sea-level extremes, cannot be well quantified along most global coastlines, including Australia's, because the high spatial variability of sea-level is under-sampled by the sparse set of long, high quality tide gauge records. Satellite altimetry provides an alternative data source with greater spatial sampling, yet experiences contamination from land within tens of kilometres from the coast and also suffers from regionally correlated biases. This project proposes to address these problems through re-tracking radar altimetry waveforms to derive new data in the coastal margin, enabling the production of new inferences on sea-level change and extremes at dramatically improved spatial resolution around Australia.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.
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
Eddies: The key to understanding Southern Ocean carbon cycling. This project plans to observe an eddy in the Southern Ocean for three weeks, to understand how its circulation affects ocean productivity and the exchange of carbon dioxide between the ocean and atmosphere. Ocean eddies are like small high and low pressure weather systems which spin either clockwise or anticlockwise, are about 100–200 kilometres across and several hundred metres deep. Eddies are important because they generate verti ....Eddies: The key to understanding Southern Ocean carbon cycling. This project plans to observe an eddy in the Southern Ocean for three weeks, to understand how its circulation affects ocean productivity and the exchange of carbon dioxide between the ocean and atmosphere. Ocean eddies are like small high and low pressure weather systems which spin either clockwise or anticlockwise, are about 100–200 kilometres across and several hundred metres deep. Eddies are important because they generate vertical currents that move nutrients and carbon dioxide up and down. Expected project outcomes will include a better understanding of carbon cycling in an ocean region that is central to the climate of Australia and the rest of the planet.Read moreRead less
The Southern Ocean Meridional Overturning Circulation: New observations of vertical mixing. The Southern Ocean and Antarctic Circumpolar Current (ACC) play profound roles in Australian and global climate. However, we know little about how they will be affected by global warming. New velocity observations will tell us how the vertical mixing that contributes to the meridional overturning circulation, and ACC strength, change with the seasons and from year to year. The observations will also gi ....The Southern Ocean Meridional Overturning Circulation: New observations of vertical mixing. The Southern Ocean and Antarctic Circumpolar Current (ACC) play profound roles in Australian and global climate. However, we know little about how they will be affected by global warming. New velocity observations will tell us how the vertical mixing that contributes to the meridional overturning circulation, and ACC strength, change with the seasons and from year to year. The observations will also give us a better understanding of the oceanic and atmospheric processes that drive these changes. This new information will allow climate models to be better constrained so they can more accurately predict changes to Australian and global climate.Read moreRead less