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
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
Antarctic marine diatoms: Key to predicting the effects of global climate change on a temperature-sensitive ecosystem. This project aims to determine the effects of global climate change on Antarctic diatoms. Diatoms are a major component of the polar phytoplankton. They are sensitive to changes in their marine environment, detection of which is an essential part of the Antarctic climate change strategy. Understanding the environmental processes that cause natural variation in extant diatoms ....Antarctic marine diatoms: Key to predicting the effects of global climate change on a temperature-sensitive ecosystem. This project aims to determine the effects of global climate change on Antarctic diatoms. Diatoms are a major component of the polar phytoplankton. They are sensitive to changes in their marine environment, detection of which is an essential part of the Antarctic climate change strategy. Understanding the environmental processes that cause natural variation in extant diatoms will make it possible to reconstruct the response of fossil diatoms, preserved in marine sediments, to past climate change. This understanding is vital for predicting the effect of future anthropogenic warming on this ecosystem.Read moreRead less
PAST EAST ANTARCTIC ICE SHEET AND GLOBAL SEA-LEVEL VARIATIONS. Unique fossil-bearing, open marine sediments occur inland from the modern Antarctic coastline. These were deposited when a now-glaciated Antarctic basin became a marine embayment, during intervals of significantly reduced ice sheet volume and elevated global sea-level in the past. Urgent palaeontological, sedimentological and geochemical research on these sediments are vital to provide: directly datable in situ evidence for major i ....PAST EAST ANTARCTIC ICE SHEET AND GLOBAL SEA-LEVEL VARIATIONS. Unique fossil-bearing, open marine sediments occur inland from the modern Antarctic coastline. These were deposited when a now-glaciated Antarctic basin became a marine embayment, during intervals of significantly reduced ice sheet volume and elevated global sea-level in the past. Urgent palaeontological, sedimentological and geochemical research on these sediments are vital to provide: directly datable in situ evidence for major ice sheet retreat and global sea-level rise in the past; and quantifiable data concerning the environment during such events; an innovative opportunity to improve predictions of Antarctica's response to global warming and answer international debate about past Antarctic Ice Sheet stability.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.
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
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
Equator to Pole: Reconstructing tropical and Antarctic climate variability over the last millennium and their impacts on southern Australian rainfall. Water resource management is one of the greatest challenges facing sustainable agriculture and urban populations across southern Australia. Key players driving catastrophic droughts in southern Australia are the tropical Indian Ocean Dipole and polar Southern Annual Mode climate systems, which affect moisture availability and transport pathways. T ....Equator to Pole: Reconstructing tropical and Antarctic climate variability over the last millennium and their impacts on southern Australian rainfall. Water resource management is one of the greatest challenges facing sustainable agriculture and urban populations across southern Australia. Key players driving catastrophic droughts in southern Australia are the tropical Indian Ocean Dipole and polar Southern Annual Mode climate systems, which affect moisture availability and transport pathways. This collaborative research project draws together a uniquely-skilled research team to develop targeted coral, ice and cave reconstructions of these climate systems and their impacts on Australian rainfall through the last millennium. This fundamental new knowledge of the drivers of Australian rainfall variability will aid improved predictability of future changes in our valuable water resources. 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
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