Water vapour study improves extreme weather forecasting

RMIT University researchers are using four-dimensional GPS modelling to measure water vapour, in the hope of improving predictions of severe weather and reducing the impact of natural disasters.

Water vapour significantly influences many weather and climate processes such as cloud formation, water redistribution and temperature control in the troposphere. This correlates to the formation and life cycle of severe storm and precipitation systems.

But although the dynamics of water vapour have a crucial effect on the formation and life cycle of severe weather, the phenomenon is not well understood. Dr Toby Manning, from the RMIT SPACE Research Centre, investigated the use of continuously operating ground-based networks and space-borne GPSs to reconstruct the 4D dynamics of water vapour in the atmosphere over time.

Dr Toby Manning.

GPS tomographic modelling has the potential to use the dense ground-based infrastructure in Australia to sense the movement of water vapour over space and time - a major leap forward in the innovative use of GNSS technology. The research is particularly significant for Australia and the Southern Hemisphere, where other meteorological sensors are limited.

By reconstructing and examining 4D models of water vapour, Dr Manning was able to analyse their components and gain a better understanding of the key triggers in severe weather formation. He said, “When introduced into numerical weather prediction models, this research has the ability to increase the accuracy of our severe weather prediction and improve our understanding of the role water vapour plays in climate studies.”

Water vapour analysis will provide crucial data to weather forecasting and climate modelling systems. Dr Manning noted, “Time is critical in disaster and emergency management, and knowing more quickly and more accurately when a severe storm is due to hit will help authorities and the community plan and prepare.”

The research has also contributed to the RMIT SPACE Research Centre’s study in GPS radio occultation, which aims to provide Australia with space-based technology platforms suitable for generating high-resolution analysis of climate conditions.