Summer Scholarship Projects- 2013

Climate-carbon cycle interactions on centennial to millennial time scales (based at UNSW)

Student: Caio Fest (home institution- Sydney University (on exchange from Universidade Federal de Santa Catarina, Brazil)

Supervised by Laurie Menviel

Past changes in the oceanic circulation had a significant impact on the climate as well as on the carbon cycle. The goal of the project is to study climate-carbon cycle interactions linked to past and possible future changes in the oceanic circulation. The work involves running numerical experiments using a model of intermediate complexity as well as analysing model outputs. A knowledge of “Matlab” and/or “Ferret” is desirable.

Spatial patterns of precipitation changes in a warming world (based at UNSW)

Student: Andrew Lowry (home institution- University of Queensland)

Supervised by Lisa Alexander

Precipitation changes in a warming world are often described as a “wet-get-wetter, dry-get-drier” pattern. However, this pattern is usually only found in global data sets that also include precipitation over the oceans. A recent study using only land-based monthly precipitation totals could not identify such a pattern. As precipitation changes over land are most relevant in terms of their societal impacts, it is important to understand how precipitation patterns, including extreme precipitation, are changing here.

This project will investigate global patterns of precipitation changes over land across a range of different observational and climate model data sets. It will consider changes in precipitation amounts at different time scales (daily to annual totals), and in particular investigate changes in extreme precipitation relative to precipitation totals. Some knowledge of data analysis programs such as R, MatLab, IDL, python, etc. is desirable.

How will the Southern Ocean respond to Anthropogenic Forcing? (based at UNSW)

Student: David Crock (home institution- University of Melbourne)

Supervised by Paul Spence

Atmospheric observations from the past few decades reveal a poleward shift and strengthening of Southern Hemisphere westerly winds that appears to be due to anthropogenic forcing, with increasing atmospheric concentrations of both ozone-depleting gases and greenhouse gases identified as playing critical roles. Concurrent oceanic observations also indicate that portions of the Southern Ocean have been warming at nearly twice the rate of the global ocean. The focus of this research project is to evaluate the Southern Ocean response to anthropogenic forcing with a particular focus on Antarctic Bottom Water formation and the Antarctic Circumpolar transport. The student will gain valuable hands-on experience in running and analysing high-resolution global ocean models.

Future projections of heat waves (based at UNSW)

Student: Nicholas Calhau (home institution- UNSW)

Supervised by Lisa Alexander

The successful candidate will contribute in determining future projections of summertime heat waves in a global climate model. Namely, they will undertake analysis on the 21-member Community Earth System Model, and construct projections of changes in a range of heat wave characteristics including their intensity, frequency and duration. Heat waves will be measured by a methodology previously constructed by the supervisors for the RCP8.5 emission scenario (‘business as usual’) up until the end of the 21st century. Analysis will initially be for Australia, however will be carried out for the globe if time permits. Such analysis will help determine the role of internal variability combined with anthropogenic activity in the future changes of heat waves. It is preferred that the candidate is reasonably strong in statistics and MATLAB scripting, or if not, in IDL, as these are the languages the heat wave code is written in.

Biological production in the ocean estimated from satellite observations and Lagrangian modelling (based at UNSW)

Student: Peter Thanh Tam Nguyen (home institution- UNSW)

Supervised by Shane Keating

Primary production by phytoplankton is the process of removing carbon dioxide from the atmosphere to form organic carbon in the ocean’s illuminated surface layers, where it can then be transported to the deep ocean. Understanding this “biological carbon pump” is an important element of global climate change predictions. We will use satellite observations of ocean colour — a proxy for phytoplankton — and Lagrangian modelling of fluid parcels to separate changes due to ocean currents from changes due to biological processes and hence estimate primary production.

Understanding the ‘memory’ of the ocean: examining large-scale ocean adjustment through satellite remote sensing

Student: Chaehyeon Chelsea Nam (home institution- Sydney University (on exchange from Seoul National University))

Supervised by Angela Maharaj

The unprecedented resolution of satellite altimetry has revealed the existence of westward propagating features in the world ocean from seasonal to decadal timescales. These are the surface signature of the ocean adjusting to perturbations and help determine the timing of climate variability such as the El Nino Southern Oscillation (ENSO) phenomenon. A student is required to conduct spectral analysis of global sea surface heights from satellite altimetry data to explore and characterise westward propagating signals in observations of sea surface heights. Depending on the student’s interest, westward propagation in remotely sensed observations will be compared to model data or emerging theories on ocean adjustment to isolate which mechanisms dominate the ocean’s ‘memory’. A basic familiarity with MATLAB is essential as well as some knowledge of physical oceanography. Basic knowledge of signal processing (e.g., Fourier or Radon Transform) would also be very useful. This project would suit a student seeking to gain experience in ocean remote sensing and/or analysing large geophysical observational datasets.

Improved estimates of North Atlantic heat and freshwater transport  (based at UTAS)

Student: Kévin Guerreiro (home institution- UTAS (on internship from Université Paul Sabatier & Ecole Nationale de Météorologie, Toulouse))

Supervised by Will Hobbs

The Atlantic Meridional Overturning Circulation (AMOC) is one of the key deep ocean circulations in the world, and is especially important for modulating the climates of N. America and western Europe; recent work also shows possible climate teleconnections to Antarctica and Australia. However, direct observations are limited to just a few key latitudes, defined by the availability of expensive arrays or useful bathymetry. In this work, the student will combine existing data from satellites and the Argo array, with in situ observations of the western boundary current, to test time series estimates of the mid latitude AMOC transport.

Cool changes in Southern Australia (based primarily at Bureau of Meteorology, Melbourne, with some time at Monash)

Student: Nicholas Loveday (home institution- Monash University)

Supervised by Jennifer Catto

During summer in the south of Australia, the passage of a cold front often brings a welcome drop in the temperature.  These events are referred to locally as “cool changes”. The abrupt change in wind direction that frequently accompanies the cool change results in an elevated bushfire risk, so understanding and forecasting these cool changes is very important. This project offers an exciting opportunity for a student researcher to contribute to this understanding. Working with scientists at the Bureau of Meteorology and Monash University, the aim of the project is to identify identify cool changes in the data from automatic weather stations (AWS) to produce climatologies of these events for various locations. If time permits, the ability of the Bureau of Meteorology’s operational numerical weather prediction system to forecast cool changes will also be assessed. This project would ideally suit a student with some experience of programming and visualisation, for example with Python, NCL, MATLAB or IDL.

Ozone and Australian climate variability (based at the Bureau of Meteorology, Melbourne)

Student: Nicholas McCarthy (home institution- University of Queensland)

Supervised by Robyn Schofield

The ozone layer helps to protect the Earth’s surface from harmful UV radiation that has impacts on both humans and ecosystems. Since the 1980’s an ozone hole has formed over Antarctica in early spring – due to man-made cluorofluorocarbons – and typically reaches maximum size in October. The ozone hole is projected to recover over the next century, however its size and strength varies from year to year. This project will explore both ozone records from the Bureau of Meteorology and climate models to investigate linkages between ozone and climate variability in the Australian region. It will involve identifying the weather patterns that lead to extreme low total column ozone (high UV) days and explore whether these patterns are projected by climate models to become more or less likely in the future.  The student will be based at the Bureau of Meteorology in Melbourne and also interact with Centre of Excellence researchers at the University of Melbourne. They will gain experience in evaluating observational data as well as the programming skills required to analyse large data sets using data analysis and visualisation software (e.g. NCL).

How much is climate change influencing Australia’s extreme temperatures? (based at University of Melbourne)

Student: Minghong Yu (home institution- Flinders University)

Supervised by David Karoly

Australia experienced its hottest summer on record in 2012-13 and recent research showed that there was a substantial human influence on these record temperatures from global warming

Changes in the average climate from global warming can lead to very large changes in the occurrence of extreme events like our record hot summer. Investigating exactly which extreme events are influenced by anthropogenic climate change is an important research goal.

In this project, you will investigate extreme seasonal and annual temperatures averaged across Australia and for each of the states using the latest state-of-the-art global climate models. Using this set of models and novel model experiments, you will analyse human influences on record Australian seasonal and annual temperatures. You will develop look-up tables for the human contribution to new record high average temperatures across Australia and provide useful information for understanding possible future climate impacts.

Water vapour transport into the stratosphere due to the Australian Monsoon (based at University of Melbourne)

Student: Sam Monkiewicz (home institution- University of Melbourne)

Supervised by Todd Lane

Water vapour is the most potent greenhouse gas. However, it is very different from anthropogenically changing gases, its atmospheric concentration is controlled by temperature. The Australian monsoon is an important region controlling stratospheric water vapour  – an important yet poorly understood climate parameter. Deep convective events – followed by slow raising air in the tropical region to the North of Australia are known to be important. In this project you will run and analyse back trajectories in the tropical upper troposphere and lower stratosphere. With the help of these trajectories you can study the air mass transport and troposphere-stratosphere-exchange processes and the impact of deep convective processes.

Rossby waves and climate variability in southern Australia (based at Monash)

Student: Mollie Burns (home institution- Monash University)

Supervised by Laura O’Brien

This is an exciting opportunity to explore the dynamics of the southern hemisphere and develop a new way of understanding climate variability in Australia.

Large amplitude Rossby waves stir up the atmosphere generating cutoff cyclones and anticyclones. This creates the weather systems we see on a daily basis such as strong winds, warmer temperatures, increased rainfall and storms. These anomalies are measured and identified through the potential vorticity. Patterns of cyclones equatorward of anticyclones induce easterly winds and may bring more rainfall to the east coast of Australia.

The Southern Annular Mode (SAM) is the north-south movement of the westerly wind belt in the Southern hemisphere and is an important driver of rainfall in southern Australia. In this project you will explore the connection between these cutoff patterns and the SAM aiming to bring a new understanding to the SAM. This will involve analysis of ERA-Interim data, using Matlab to create composites of the frequency of these cutoff anomalies in the Southern hemisphere during positive and negative modes of the SAM.

The impact of modelled sea surface temperature errors on Australian Climate (based at Monash)

Student: Alex Cameron (home institution- Monash University)

Supervised by Duncan Ackerley

This project offers the opportunity to contribute to important research on understanding changes in Australian climate.

Tropical sea surface temperatures (SSTs) have a large impact on the global circulation. Convection over warm waters produces heating in the atmosphere. This sets off Rossby waves, which impact the location of the jet stream and the paths of extratropical cyclones and fronts.

Many climate models have large tropical SST errors. In particular, they are known to have errors that directly affect the climate of Australia. In this project, the influence of different tropical SST errors will be investigated using a number of climate model simulations. The work will provide a vital assessment of these errors, which will contribute to improving estimates of future climate changes.

The student researcher would apply existing programs and write their own programs to calculate various statistics and visualise the data from the model simulations. They will have the opportunity to write up this work and potentially contribute to a peer‐reviewed publication.

A hail climatology for Victoria and associated proximity environments (based at Monash)

Student: Adam Brownstein (home institution- Monash University)

Supervised by Hamish Ramsay

Severe thunderstorms are among the most costly natural hazards to affect Australia each year, yet compared to other hazards, such as tropical cyclones, we know relatively little about their climatology and associated formative environments.  The Bureau of Meteorology defines a severe thunderstorm as one which produces any of: hail of 2cm diameter or greater; wind gusts of 90 km/h or greater; flash floods; or tornadoes.

Drawing on the Bureau of Meteorology’s severe storm archive as a starting point, the first part of this project will be to produce a detailed climatology of hail events over Victoria, including spatial distribution, severity, and seasonality.  The second part of the project, time permitting, will involve the use of proximity soundings to analyse the environments in which these storms formed.

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