Remote Sensing of the Earth's Lower Atmosphere During Severe Weather Events Using GPS Technology: A Study in Victoria, Australia

Suelynn Choy, Kefei Zhang, Chuan-Sheng Wang, Ying Li, Yuriy Kuleshov

Abstract:	The aim of this work is to assess the potential of using ground- and space-based GPS observations for severe weather diagnoses, particularly in studying and monitoring thunderstorm occurrences. It is of interest to determine if a severe thunderstorm will leave a significant signature in the GPS ground-based Precipitable Water Vapour (PWV) estimates and space-based Radio Occultation (RO) profiles during the development, maturity and dissipation stages. A severe thunderstorm event in March 2010, which brought heavy rainfall, large hail stones, strong winds and flash flooding to the state of Victoria, Australia, was used as a case study. The results indicate that there is strong spatial and temporal correlation between variations of the GPS-PWV estimates and the passage of the storm. In fact, the estimated GPS-PWV conformed to radiosonde observations as well as the amount of cumulative rainfall produced from the storm. This finding is very encouraging as the ground-based GPS techniques can be considered as a supplemental meteorological sensor in studying, monitoring, and potentially predicting severe weather events. The advantage of using ground-based GPS-PWV technique is that it is capable of providing continuous observation of the storm passage with high temporal resolution; while the spatial resolution of the distribution of water vapour is dependent on the geographical location and density of the GPS stations. The results from the space-based GPS RO limb sounding technique, on the other hand, are not as robust. Although GPS RO can capture the dynamics of the troposphere and lower stratosphere with high vertical resolution, its limited geographical coverage in a local region and its temporal resolution over a short period of time raise an important question about its potential for monitoring severe weather events, particularly local thunderstorms which have a relatively short life-span. GPS RO technique will be more suitable for long term climatology studies over a large area. In addition, the quality of GPS RO soundings and retrievals in the lower troposphere decrease during the storm passage as RO refractivity is extremely sensitive to moisture content in the troposphere. It is anticipated that the findings from this study will encourage further discussion and research into using GPS meteorology technique for monitoring and forecasting severe weather events.
Published in:	Proceedings of the 24th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2011) September 20 - 23, 2011 Oregon Convention Center, Portland, Oregon Portland, OR
Pages:	559 - 571
Cite this article:	Choy, Suelynn, Zhang, Kefei, Wang, Chuan-Sheng, Li, Ying, Kuleshov, Yuriy, "Remote Sensing of the Earth's Lower Atmosphere During Severe Weather Events Using GPS Technology: A Study in Victoria, Australia," Proceedings of the 24th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2011), Portland, OR, September 2011, pp. 559-571.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In