Summary
This presentation introduces a recently awarded Australian Antarctic Science (AAS) project as part of the research theme 1 'Climate Processes and Change'. This project utilises the technique of Global Positioning System (GPS) Radio Occultation (RO), where the GPS L-band frequency signals are refracted as they pass through the earth's atmosphere and received by low earth satellites, to study the physical properties of the earth’s atmosphere over the Antarctic region. The emerging GPS RO technique for monitoring the earth’s atmosphere is robust and provides high accuracy and high vertical resolution data (e.g. COSMIC, CHAMP,…). Radiosonde data has typically been used in the past to study climate, however the accuracy of radiosonde data and the output of climate models over the Antarctic region is significantly limited by the small number of radiosonde stations. Space-based RO is particularly suited to monitoring atmospheric variability in the Antarctic region. The GPS RO dataset covers more than 10 years of atmospheric measurements, providing atmospheric information that can be used to identify short term climate trends and aid in climate prediction. GPS RO provides high accuracy, unbiased, global measurements in previously under-represented regions that can be used to improve current numerical weather prediction. The background and basic concepts of GPS RO will be introduced as well as the major tasks and challenges of the AAS project. Preliminary results of atmospheric profile comparisons between the radiosonde and RO datasets and short term climatic trends in the Antarctic region using GPS RO will be presented.