GPS radio occultation for studying the Antarctic atmosphere and climate

This project uses the radio occultation (RO) technique to study the physical properties of the Antarctic atmosphere.

The radio occultation (RO) technique sees electromagnetic signals refracted as they pass through the Earth’s atmosphere. Signals from GPS to Low Earth Orbit (LEO) satellites will be monitored as they pass through the atmosphere to reveal important atmospheric properties such as temperature, pressure, refractivity and relative humidity.

This information will be used in a feasibility study into the use of RO for meteorological and climate analyses over the Antarctic region.

This research aims to investigate long-term weather trends over the Antarctic region and the Southern Hemisphere by assimilating GPS RO measurements into existing NWP models. The limitations of the space-based Earth environmental sensing technique will be investigated and new methodology will be proposed. The methodology will enhance the accuracy and capability of this technique with the aim to improve the current weather prediction models and forecasting accuracy.

The objectives of this project include:

  • To compare GPS RO height profiles of pressure, temperature, water vapour pressure and refractivity with Radiosonde (RS) measurements in the Antarctic region
  • To compare the atmospheric parameters derived from GPS RO technology with radiosonde (RS) measurements as a function of monthly average and to analyse the diurnal and seasonal trends
  • To examine the variation in GPS RO temperature versus pressure measurements over Antarctica and over the surrounding oceans
  • To study the temporal and spatial trends in the characteristics of the Tropopause in association with the Polar Front Jets using GPS RO
  • To investigate the Tropopause height, temperature and pressure in the Antarctic region using GPS RO measurements and to identify any trends in these parameters that may be associated with other atmospheric parameters, such as Sea Surface Temperature and ozone concentration, during GPS RO satellite missions
  • To utilise the temperature measurements derived from GPS RO at given pressure levels to study long-term trends
  • To assimilate GPS RO measurements from the Antarctic region into the Australian Bureau of Meteorology’s (BoM) Australian Community Climate and Earth-System Simulator (ACCESS) Numerical Weather Prediction (NWP) model
  • To determine the impact of utilising GPS RO measurements in the ACCESS NWP model for improving the forecast accuracy associated with long term weather trends over the Antarctic region
  • To use high vertical resolution GPS RO measurements, with other supporting ground-based and space-based remote sensing techniques, to study the climate-related trends in the fine-scale structure of the Troposphere and Stratosphere.


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RMIT University acknowledges the people of the Woi wurrung and Boon wurrung language groups of the eastern Kulin Nation on whose unceded lands we conduct the business of the University. RMIT University respectfully acknowledges their Ancestors and Elders, past and present. RMIT also acknowledges the Traditional Custodians and their Ancestors of the lands and waters across Australia where we conduct our business. - Artwork created by Louisa Bloomer