Undergraduate opportunities at the University of Tasmania

Different Metrics, Different Heat: Comparing Humid Heat Across Australia

Supervisors: Cindy Deng-Nguyen, Amil Wickramasinghe

Extreme heat poses a major risk to human health, but defining how “hot” conditions are is surprisingly complicated. A range of different metrics are used to describe heat stress, often combining temperature and humidity in different ways. As a result, different metrics can give contrasting representations of hot conditions and may even disagree on whether heat extremes are becoming more or less severe. This project will compare commonly used heat stress metrics across Australia. The project will investigate their climatology and spatial patterns, where and why the metrics agree or disagree, and which metrics are most informative for Australia’s diverse hot-dry and hot-humid climates.

Requirements: Python / programming skills are desirable.

Ocean Response to Rapid Entrainment

Supervisor: Christopher Aiken

When the first large storms of Autumn cross the ocean, they mix the warm surface water into the ocean interior, leaving a narrow trail behind them of colder water at the surface and a deeper mixed layer beneath. How does the so-formed “kink” in the mixed layer depth evolve over time? In this project you will analyse existing model simulations, and possibly running your own, to investigate how the ocean interior adjusts to these sudden episodes of deep mixing.

Dynamical Stability of Meandering Ocean Jets

Supervisor: Christopher Aiken

A remarkable aspect of the ocean circulation is that the flow tends to form itself into strong narrow “jets” rather than just broad, weak currents. These jets are “unstable”, in the sense that they tend to distort and meander, changing their path constantly but without losing their jet structure. This project will involve digging into the theory of “thin jets”, and performing some “stability analysis” with the aim to understand why they meander in the way that they do.

How well do Argo floats see ocean currents?

Supervisor: Christopher Aiken

The Argo program of drifting buoys has given oceanographers an incredible, previously unknown view of the ocean, from the surface to depths of up to 6,000m.  There are now over 4,000 of these amazing autonomous buoys spread throughout the world’s ocean.  But are they providing an accurate picture of the ocean circulation? Because the buoys drift freely with the currents, over time they may tend clump together in regions of low flow, like leaves in a corner on a windy day. The project will test how well the Argo buoys are resolving the narrow regions of fast currents in the ocean.

Requirements: Enthusiasm. Not scared of computers.

Using an ocean model to interpret upper-ocean observations from the Southern Ocean Timeseries

Supervisor: Madelaine Rosevear, Paul Spence

Heat supplied by the ocean to the atmosphere fuels weather systems and climate variability. Mixing in the upper ocean, and the depth of the ocean mixed layer, is a key control on sea surface temperature, and therefore this heat supply. The Southern Ocean Timeseries (SOTS) mooring (2015-ongoing) is the longest-running atmosphere and ocean observing system in the Southern Ocean, and collects dense temperature measurements in the upper ocean. However, fewer salinity measurements are made, making it challenging to define the mixed layer depth. This summer project will use output from a new regional ocean model experiment to determine how well the mixed-layer depth can be determined from temperature data alone. Results from the project will build understanding about Southern Ocean surface processes and aid in interpreting valuable data from the SOTS mooring. 

Requirements: Some programming experience (e.g., Python/Jupyter notebooks) and some exposure to physical oceanography concepts is desirable. 

Observations vs Models: An Air-Sea Flux Southern Ocean Time-Series Story

Supervisor: Madelaine Rosevear, Paul Spence, Cindy Nguyen-Dang

This project will conduct an observation vs model evaluation of air–sea interactions near the Southern Ocean Time Series (SOTS) mooring. Working with the long, quality-controlled SOTS record south of Tasmania at ~46.7°S, 142°E (2010–present), you’ll (i) evaluate the SOTS mooring data, (ii) compare the SOTS data with ACCESS-OM2 model configurations to better understand air-sea interactions, and (iii) as a stretch goal, run a regional nested model of the SOTS region at submesoscale resolution (~1 km → 300 m). The core analysis will collocate mooring and model data, evaluate bulk air-sea fluxes and their impact on ocean dynamics, and assess how well ACCESS-OM2 models captures air-sea interactions near SOTS. All work will be done with python/xarray notebooks on Australian supercomputers, producing clear figures and a short write-up with recommendations for improving model representation in the SOTS sector.

Requirements: Knowledge of python programming and jupyter notebooks.

Impact of ocean heat release on cold air outbreaks

Supervisor: Christopher Aiken, Liz Ritchie-Tyo

Cold air blowing over a warm ocean can result in a large and sudden transfer of heat from the ocean to the atmosphere.  And it may be even larger than we previously thought.  New research suggests that our models may underestimate how much heat is lost from the ocean during these “cold air outbreak” (CAO) events.  The project will investigate how this underestimation of the sea-to-air heat flux might impact the weather during CAO events.  To do this the student will run and/or analyse numerical weather models.

Requirements: Confident with scientific computing. Ideally good python skills.  Background and interest in ocean or atmosphere science.