QAS projects are aligned with the research priorities of the AAD and the University of Tasmania, and fall into three broad themes that follow the Australian Antarctic science strategic plan. Prospective students are encouraged to develop project proposals in the following areas, in consultation with relevant AAD and UTas academic staff:
- physical oceanography
- ice sheet modelling
- biogeochemical modelling
- natural resource management
- solid earth geophysics
- ecological modelling
- atmospheric processes in climate models
Some specific project ideas are outlined below. If you are interested in any of these projects, please contact the relevant staff members.
Investigation of changes in atmospheric storm tracks and East Antarctic surface accumulation
Contact: Dr Petra Heil, Jason Roberts
The Antarctic ice sheets are a critical component of the dynamic link that couples the spatially and temporally varying components of the Earth system. Recent ice-shelf breakup (e.g. the Larsen and Wilkins ice shelves) and glacier tongue disintegration has increased the exposure of the Antarctic ice sheet and may lead to changes in the mass and geometry of high Antarctic ice masses. This project will focus on quantifying the processes that affect moisture flux onto the East Antarctic ice sheet, and their subsequent effects on the East Antarctic surface mass balance and geometry. Data will include meteorological data from automatic weather stations and manned observatories (station, vessels), and remotely-sensed parameters. Numerical models will be used to characterize the effects of these parameters on the surface accumulation of the ice sheets.
Identification of key drivers of ice edge blooms off East Antarctica
Retreating sea ice in spring and summer can trigger extensive phytoplankton development, by inducing stratification of the ocean's surface layer and release of sea ice algae and ice-bound micro-nutrients into the water column. Off East Antarctica, ice edge blooms are temporally and spatially dynamic and the physical and biological key drivers in their occurrence and development remain unclear. The objective of this project is to assess the relative importance of various processes in triggering ice edge phytoplankton blooms. Data will be taken from remotely-sensed sources (e.g. ocean colour and sea ice concentration), model outputs, and in-situ observations. Numerical and statistical methods will be used to examine the influences of various processes, and to use those models to characterize and predict regional patterns in ice-edge phytoplankton blooms.
The role of sea ice kinematics on the state of Antarctic sea ice
Sea ice is a crucial component of the Earth system due to its roles in controlling energy and moisture transfer between the ocean and atmosphere, ice-albedo feedback connected to polar amplification, and in marine ecosystems and bio-geochemical activity. This project will seek to quantify and characterize sea ice motion and deformation in the Southern Ocean, with a view to determining the drivers of these processes and to estimate their susceptibility to change under predicted atmospheric and/or oceanic change. The methods used for this project will include time-series analysis of Lagragian data, image cross-correlation of satellite-based swath data, and optimal interpolation to determine the baseline of Antarctic ice kinematics. Statistical analysis, including linear models and multi-variable correlation analysis will be used to determine the effect of external forcing on the sea ice.
Quantitative analysis of phytoplankton populations using pigment markers
Contact: Dr Simon Wotherspoon, Dr Simon Wright
Photosynthetic pigments (chlorophylls and carotenoids) are widely used as biomarkers to determine the abundance and taxonomic composition of phytoplankton populations. However, interpretation of pigment data is difficult because of the great diversity of pigment patterns in algae, and because the pigment content of each taxon can be variable. The CHEMTAX software, developed by CSIRO and the AAD, is the prime analytical tool for pigment-based marine ecology worldwide. This project will study recent developments in this field, including Bayesian methods (van den Meersche et al. 2008, Whiten et al. 2011), develop new software for use by the world's oceanographic and limnological communities, and study methods to improve analysis where ecological gradients (e.g. latitude or time) cause changes in the pigment ratios or communities.
Effect of ocean acidification on physiology and growth of Antarctic krill
Contact: Dr So Kawaguchi, Dr Kerrie Swadling
Researchers at the AAD have recently shown that early embryonic development of krill is inhibited by ocean acidification caused by increased CO2 levels (Kawaguchi et al. 2011, 2013). This project aims to assess the sensitivity of Antarctic krill to ocean acidification using laboratory-based experiments. This information will then be used to identify how factors such as CO2 level, temperature, and food affect growth and metabolic parameters of krill, and to refine existing krill growth models.
Tidal melting of Antarctic ice shelves since Last Glacial Maximum
This PhD project will use a numerical ocean model to examine the role of tidal currents in the retreat of the Antarctic ice sheet since the Last Glacial Maximum. Model runs will be performed in order quantify ice shelf basal melt rates for a series of LGM and post-LGM ice sheet configurations. Extensions to this work include application to a time-stepping coupled ice-ocean model to quantify the total effect of tidally-driven basal melt on post-LGM ice sheet retreat. The student will have access to appropriate computer models as part of a larger modeling effort within UTAS / ACE CRC. Simulations will be performed using grants and allocated resources within the National Computing Infrastructure and the Tasmanian Partnership for Advanced computing.
High resolution modeling of the retreat of the East Antarctic Ice Sheet since the Last Glacial Maximum
There is great uncertainty surrounding the degree to which the Antarctic Ice Sheet has contributed to sea level since the Last Glacial Maximum (LGM). The vast East Antarctic ice sheet is particularly poorly understood. This PhD project will use a high resolution ice stream/ice shelf model in order to better understand the retreat history of one of East Antarctica's major drainage basins, the Amery Ice Shelf/Lambert Glacier system. Model runs will be performed in order to best-fit geological and geodetic constraints, examining the response of the ice sheet to changes in ice-shelf basal melting, accumulation and relative sea level change. Extensions to this work include application to other major glacier/ice shelf systems and incorporation of the results in a model of Earth's response to ice-ocean loading changes, known as glacial isostatic adjustment. The project will use published ice history data and other publicly available data. Simulations will be performed using grants and allocated resources within the National Computing Infrastructure and the Tasmanian Partnership for Advanced computing.
Adélie penguins as ecosystem indicators: foraging behaviour and habitat
Adélie penguins are the most abundant Antarctic penguin species whose krill dependence and sensitivity to the sea ice environment mean they are an important "indicator species" for the Commission for the Conservation of Antarctic Marine Living Resources Ecosystem Monitoring Program (CEMP). This project will analyse long-term satellite telemetry data from Béchervaise Island and other colonies to focus on the specific interactions between Adélie penguin movements, diving behaviour and their environment. The work program could include syntheses of available dive data and derivation of indicators of relative dive effort and cost, assessment of both horizontal and vertical movement behaviour as foraging indicators, integration of penguin movement and diving behaviour with environmental information and with direct prey-field information from corresponding acoustic prey-field surveys, and analyses of the long-term archive of penguin movement data from satellite tracking studies. Such assessments of functional relationships should enable tracking studies to feed into efficient and realistic representation of marine mammals and birds in ecosystem and food web models as well as delivering towards identification of, and monitoring/indicator-based approaches for, ecological responses to change.
Biophysical modelling of Antarctic krill: key habitats, ocean transport and dependent marine predators
Krill play a central role in Southern Ocean foodwebs, and have a unique lifecycle that utilises fundamentally different habitats at different life stages. This project will use biophysical modelling approaches to model krill habitat use at larval, juvenile and adult stages and to explore interactions with krill predators. The project will use output from a sea ice model and expand upon a set of recently developed algorithms to identify key areas for under-ice larval krill habitat, based on both food availability and habitat complexity. Transport modelling approaches will then be used to identify key locations for recruitment of juvenile krill to the adult population, and to relate these to large-scale patterns of krill flux, focusing in particular on the Indian Sector of the Southern Ocean. Evaluation and interpretation of these spatio-temporal predictions may utilise both ship-based observations of Antarctic marine predators (whales and flying seabirds) as well as available electronic tracking datasets (seals and penguins). These models will be used to evaluate potential responses of krill populations under IPCC climate change scenarios, and the associated implications for krill-dependent predators. Here there may also be scope to develop specific habitat suitability models for key CCAMLR indicator species such as Adélie penguins. Modelling approaches to represent habitat use by larval, juvenile and adult krill will help to inform our understanding of krill population responses to environmental change. These models will also contribute to informing management of the Southern Ocean krill fishery, and to interpreting interactions between krill prey and their dependent predators.
New and improved environmental surrogates for the Southern Ocean and their utility for quantifying and predicting biological patterns
The Southern Ocean and Antarctica are vast and remote and collecting in situ physical and biological data is challenging. Information from satellites, oceanographic floats, and other remotely sensed data provide synoptic information about the physical environment of the Southern Ocean that can be integrated into numerical or statistical models and validated with in situ data. This is an effective approach to maximising the utility of sparse biological data. The aim of the project is to improve the variety, coverage and/or resolution of key physical variables currently available for the Southern Ocean and Antarctica, evaluate their usefulness for describing biological patterns and to use these variables, in conjunction with other variables, to enhance our understanding of the distribution of benthic and pelagic organisms. The broad objectives are to (a) utilise existing physical datasets and numerical or mechanistic models to extend the spatial coverage of and, in certain regions, downscale estimates of key ocean variables (for example carbon flux and pH) (b) contribute to the development of new physical variables to characterise the biologically-relevant properties of the Southern Ocean at a range of spatial scales and resolutions, and (c) evaluate and apply these surrogates for describing and predicting patterns in the distribution of zooplankton and benthic invertebrate organisms.