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
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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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
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
Resilience of eucalypts to future droughts. This project aims to examine how resilient Eucalyptus species are to future droughts by combining data synthesis, manipulative experiments and modelling. Climate change is expected to increase the frequency, magnitude and duration of future droughts, with major environmental and socio-economic consequences for Australia. Current predictive capacity is extremely limited: experiments are limited in scale and cannot capture important global change interac ....Resilience of eucalypts to future droughts. This project aims to examine how resilient Eucalyptus species are to future droughts by combining data synthesis, manipulative experiments and modelling. Climate change is expected to increase the frequency, magnitude and duration of future droughts, with major environmental and socio-economic consequences for Australia. Current predictive capacity is extremely limited: experiments are limited in scale and cannot capture important global change interactions, whilst models do not represent the functional characteristics and adaptions of eucalypts. This project will develop a strong evidence- and process-based understanding to quantify the functional behaviour of drought-adapted Eucalyptus species and leverage this insight to make future model projections.Read moreRead less
Towards a climate theory of tropical cyclone formation. In Earth's current climate, about 80 to 90 tropical cyclones form every year around the globe, but the reasons why cyclones form at this rate are unknown. This project will use a combination of theoretical techniques and numerical simulation to elucidate the links between large-scale climate and the rate of tropical cyclone formation. A series of climate model experiments will be performed that also have the potential to improve confidence ....Towards a climate theory of tropical cyclone formation. In Earth's current climate, about 80 to 90 tropical cyclones form every year around the globe, but the reasons why cyclones form at this rate are unknown. This project will use a combination of theoretical techniques and numerical simulation to elucidate the links between large-scale climate and the rate of tropical cyclone formation. A series of climate model experiments will be performed that also have the potential to improve confidence in our predictions of tropical cyclone incidence in a future, changed climate.Read moreRead less
Oxygen isotope discrimination during C4 photosynthesis. Plants with the C4 photosynthetic pathway, like sugarcane and pasture grasses, are vital to Australian agriculture and natural ecosystems. This project will use novel laser spectroscopy to measure oxygen isotope discrimination during photosynthesis and quantify the influence of C4 plants on isotopic signatures of atmospheric CO2.
Glacio-isostatic effects on geodetic data: Ice and sea level implications. Glacio-isostatic (GI) effects are recorded in geological and geodetic data sets and mask other deformational processes. This project builds on past work using geological data with a focus on combining geodetic and geological evidence to improve knowledge of the past ice sheets, separate out effects of past and present deglaciation and develop improved models for the mantle rheology to include time-dependencies in mantle r ....Glacio-isostatic effects on geodetic data: Ice and sea level implications. Glacio-isostatic (GI) effects are recorded in geological and geodetic data sets and mask other deformational processes. This project builds on past work using geological data with a focus on combining geodetic and geological evidence to improve knowledge of the past ice sheets, separate out effects of past and present deglaciation and develop improved models for the mantle rheology to include time-dependencies in mantle response (transient creep in the first instance). The project aims to provide a complete and predictive description of the GI effects on geodetic data, consistent with geological evidence, such that other tectonic, hydrologic and sea-level signals can be estimated free of these effects.Read moreRead less
Understanding the Southern Ocean overturning circulation and its sensitivity to climate variability. Our ability to understand and ultimately predict climate is critically dependent on understanding the Southern Ocean circulation and its sensitivity to atmospheric variability. The project will use a combination of observations and high-resolution numerical models to provide insights into the dynamics of the Southern Ocean overturning circulation.