Space science

The Space Physics Group conducts research in the following areas: 

  • ionospheric physics including the study of high latitude global plasma convection
  • space-weather and ionospheric data products of interest to HF communicators and ionospheric researchers
  • remote sensing using HF radars such as measurements of sea-state conditions
  • the effects of aerosols on the upper atmosphere such as those generated by Australian bushfires.

Dr Andrew McDonald

The TIGER HF Radar Group

The SuperDARN HF radars, phased-arrays made up of many HF antennas, are used to detect backscatter from plasma density irregularities in the high latitude ionosphere.

This research involves the use of high powered HF radars, to probe the upper reaches of the earth's atmosphere. We are particularly interested in the ionosphere, a partially ionised layer of the atmosphere at around 100 km to 500 km in altitude. 

The ionosphere acts like a window into space. Electric and magnetic fields originating in the near-earth environment and in the sun, drive the ionosphere around the globe by electrodynamic processes, in contrast to the thermodynamic processes which drive the lower atmosphere. The earth's ionosphere is extremely dynamic, circulating at speeds of around 5000 km per hour.

Snapshot showing the range and power of echo returns from the TIGER Bruny Island HF Radar operated by La Trobe University. The location and velocity of the scattering targets provides insight into the dynamics of high latitude plasma convection.

We hope to better understand the movement of the upper atmosphere, and also the response of the ionosphere to violent events on the sun such as solar flares.

This research is critical to satellite operations in close earth orbits, GPS navigation, long distance radio communications and also in understanding auroras, the light-shows seen in the polar regions.

For more information, see the TIGER HF Radar website.

Atmospheric Physics Group 

The Swedish satellite platform ODIN was launched in 2001 into a 600 km sun-synchronous, near-terminator orbit with global coverage. The OSIRIS instrument on board ODIN measures limb-scattered solar radiance in the 270-810 nm spectral range.

We conduct research into the dynamics and variability of ozone and aerosols in the stratosphere. In particular we focus on the UTLS region (upper troposphere and lower stratosphere) and its relation to climate change. 

Recently we used satellite data from OSIRIS, onboard the Odin satellite, and from MLS, onboard the Aura satellite, to analyse the atmospheric ozone response to bushfire smoke aerosols from the Black Saturday bushfires. This pushed aerosols high into the stratosphere which has important consequences for climate change and the ability for climate models to accurately represent changes within the atmosphere.

A daily limb-scattered radiance map in the 795 nm spectral range. Strong stratospheric enhancement is observed over Australia due to increased aerosol scattering associated with the Black Saturday bushfire smoke plume.Other research focuses on the use of coupled chemistry climate models to infer future scenarios of stratospheric ozone recovery over Antarctica. 

This research contributes to our knowledge of transport mechanisms for ozone in the UTLS region which is vital in predicting surface UV radiation and for understanding long term changes in climate. Extreme events such as the Black Saturday bushfires can affect a larger part of the atmosphere than has been previously realised, affecting our climate both in Australia and globally. 

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