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
Links between bushfires in Victoria and floods in Queensland. This project will investigate connections between bushfires in Victoria and floods in Queensland under the framework that atmospheric blocking can be thought of as a common link. High resolution runs using the Intergovernmental Panel on Climate Change future projections of the energetics of high impact weather will improve climate forecasts in sensitive coastal areas of the country.
What determines plant sensitivity to heat?: Individual to lifetime impacts. Temperature is a major determinant of the distribution of species and yet the capacity to predict the thermal sensitivity of plants is extremely limited. How vulnerability varies as a plant grows from seed to adult and produces more seed is a key question. Whether chronic warming exacerbates or ameliorates effects of extreme events, e.g. triggering the plant to enlist defensive strategies, is also an open question. This ....What determines plant sensitivity to heat?: Individual to lifetime impacts. Temperature is a major determinant of the distribution of species and yet the capacity to predict the thermal sensitivity of plants is extremely limited. How vulnerability varies as a plant grows from seed to adult and produces more seed is a key question. Whether chronic warming exacerbates or ameliorates effects of extreme events, e.g. triggering the plant to enlist defensive strategies, is also an open question. This project will advance fundamental understanding of how thermal tolerance varies across species and over the plant life cycle and how it scales demographically to lifetime vulnerability. The work will yield a significant advance in our capacity to predict impacts of extreme heat events on plant performance and distribution.
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Tropical climate change, the Hadley and Walker Circulations, and Australian climate. Tropical climate systems, especially the overturning circulations and monsoons, have undergone change in recent decades and are expected to do so over the next century. However, a full understanding of these has proved elusive. The project will employ a suite of insightful diagnostics of these tropical circulations calculated from the latest, high-quality data and the results of modelling to isolate the key phys ....Tropical climate change, the Hadley and Walker Circulations, and Australian climate. Tropical climate systems, especially the overturning circulations and monsoons, have undergone change in recent decades and are expected to do so over the next century. However, a full understanding of these has proved elusive. The project will employ a suite of insightful diagnostics of these tropical circulations calculated from the latest, high-quality data and the results of modelling to isolate the key physical mechanisms at work. The research is significant in that tropical circulations determine the precipitation and temperature over large parts of the Earth’s surface, and particularly Australia. The physical underpinning of the changes will assist in forming outlooks for future climate for the ‘wet tropics’ and the ‘dry zones’.Read moreRead less
Southern Ocean aerosols: sources, sinks and impact on cloud properties. This project aims to provide fundamental process-level understanding of atmospheric aerosol processes over the Southern Ocean, a region that has a profound influence on the Australian and global climate and where climate models perform poorly. Comprehensive observations during 3 Southern Ocean voyages and land-based measurements will enhance our knowledge of aerosols and cloud formation in that region and provide much-needed ....Southern Ocean aerosols: sources, sinks and impact on cloud properties. This project aims to provide fundamental process-level understanding of atmospheric aerosol processes over the Southern Ocean, a region that has a profound influence on the Australian and global climate and where climate models perform poorly. Comprehensive observations during 3 Southern Ocean voyages and land-based measurements will enhance our knowledge of aerosols and cloud formation in that region and provide much-needed data for improving global climate models. Expected outcomes include more accurate seasonal and latitudinal representations of Southern Ocean aerosol populations, properties and sources. The main benefit includes improvements in weather forecasting and future climate projection for Australia and the Southern Hemisphere.Read moreRead less
Ocean heat content change and its impact on sea level. This project aims to improve projections of possible sea level changes. Sea level rise is among the most significant potential impacts of transient climate change around the world. Poor understanding of the way in which heat is absorbed at the sea surface and distributed by ocean circulation is a leading source of uncertainty in projections of global surface temperature and regional sea level rise by the end of this century. This project aim ....Ocean heat content change and its impact on sea level. This project aims to improve projections of possible sea level changes. Sea level rise is among the most significant potential impacts of transient climate change around the world. Poor understanding of the way in which heat is absorbed at the sea surface and distributed by ocean circulation is a leading source of uncertainty in projections of global surface temperature and regional sea level rise by the end of this century. This project aims to apply novel observational methods, complimented by numerical modelling, to quantify the drivers of recent change. This project expects to transform our ability to predict how ocean temperature and sea level will change in the future.Read moreRead less
Are subterranean estuaries a source or sink of greenhouse gases? The aim of this project is to investigate the role of subterranean estuaries and submarine groundwater discharge on the marine cycle of the greenhouse gases carbon dioxide, methane, and nitrous oxide. The expected outcome of this project is a better understanding of the role of coastal environments as a net source or sink of greenhouse gases.
Trends in polar sea ice and associated global atmospheric circulations. The project aims to analyse the trends in sea ice extent over the polar regions, and explain them in terms of changes in the local and remote atmospheric circulation. In recent decades, Arctic sea ice has decreased dramatically, while increasing in the Antarctic. The resolution of this paradox is a pressing issue in climate science, as is the broad question of how sea ice influences, and is influenced by, climate conditions ....Trends in polar sea ice and associated global atmospheric circulations. The project aims to analyse the trends in sea ice extent over the polar regions, and explain them in terms of changes in the local and remote atmospheric circulation. In recent decades, Arctic sea ice has decreased dramatically, while increasing in the Antarctic. The resolution of this paradox is a pressing issue in climate science, as is the broad question of how sea ice influences, and is influenced by, climate conditions in the mid-latitudes and tropics. Anticipated outcomes include a better understanding of the nature of links between Australian climate and Antarctic ice, and between United States climate extremes and Arctic ice.Read moreRead less
Linking wave–sea ice feedbacks to rapid ice retreat. Antarctic sea ice extent has been in sharp decline since 2016, which is stressing the fragile Southern Ocean and Antarctic environments so vital to the global climate. This project aims to investigate a crucial candidate mechanism of sea ice loss by predicting rapid ice retreat in response to large Southern Ocean waves. New theory and modelling capabilities that account for wave–ice feedbacks will underpin the predictions, leveraging on recent ....Linking wave–sea ice feedbacks to rapid ice retreat. Antarctic sea ice extent has been in sharp decline since 2016, which is stressing the fragile Southern Ocean and Antarctic environments so vital to the global climate. This project aims to investigate a crucial candidate mechanism of sea ice loss by predicting rapid ice retreat in response to large Southern Ocean waves. New theory and modelling capabilities that account for wave–ice feedbacks will underpin the predictions, leveraging on recent research breakthroughs, including novel datasets derived from satellite and field observations. The outcomes are expected to quantify sea ice retreat due to ocean waves for the first time, with potentially major implications for coupled wave–sea ice modelling in climate studies.Read moreRead less
Unsaturation of vapour pressure inside leaves: fundamental, but unknown. This project aims to determine when and to what extent the air inside leaves becomes unsaturated with water vapour. All current interpretation and modelling of leaf gas exchange assumes saturation under all circumstances. Compelling evidence has been obtained that suggests this is not true under moderate air vapour pressure deficits. A novel technique will be employed to assess the water vapour concentration of the air insi ....Unsaturation of vapour pressure inside leaves: fundamental, but unknown. This project aims to determine when and to what extent the air inside leaves becomes unsaturated with water vapour. All current interpretation and modelling of leaf gas exchange assumes saturation under all circumstances. Compelling evidence has been obtained that suggests this is not true under moderate air vapour pressure deficits. A novel technique will be employed to assess the water vapour concentration of the air inside leaves based on stable isotope analysis of carbon dioxide and water vapour exchanged between leaves and air. The project is expected to provide fundamental knowledge about how stomata regulate photosynthesis and water use, with significant implications for modelling vegetation function and for improving the performance of crop plants.Read moreRead less