A team of researchers from Sapienza University in Rome, Italy, and NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California had developed a new system for monitoring changes in the Earth’s ionosphere in real-time to improve tsunami detection.
The new system, called Variometric Approach to Real-Time Ionosphere Observation, or VARION, relies on GPS and a number of other global navigation satellite systems (GNSS).
Real-time detection of ionospheric perturbations caused by the Queen Charlotte tsunami on 27 October 2012. Image courtesy of Sapienza University/NASA-JPL/Caltech.
Using signals transmitted by GNNS, the research team was able to identify changes to the density of electrons in the ionosphere, which occur and become visible as internal gravity waves, caused, in turn, by the undulation of oceans due to a developing tsunami, reach an altitude between 300-350 kilometres above the surface.
“VARION is a novel contribution to future integrated operational tsunami early warning systems,” said the author of the algorithm Giorgio Savastano. “We are currently incorporating the algorithm into JPL’s Global Differential GPS System, which will provide real-time access to data from about 230 GNSS stations around the world that collect data from multiple satellite constellations, including GPS, Galileo, GLONASS and BeiDou.”
Combined with other detection systems, VARION could be used to provide a more accurate assessment of individual earthquake events and related risks once an earthquake is detected.
“We expect to show it is feasible to use ionospheric measurements to detect tsunamis before they impact populated areas,” said supervisor of JPL’s Ionospheric and Atmospheric Sensing Group Attila Komjathy. “This approach will add additional information to existing systems, complementing other approaches. Other hazards may also be targeted using real-time ionospheric observations, including volcanic eruptions or meteorites.”
Interactions between the ionosphere and terrestrial weather below remain an important research direction for NASA, with two new missions – the Ionospheric Connection Explorer and the Global-Scale Observations of the Limb and Disc – planned for early 2018.
The ultimate goal of research into the ionosphere is to gather enough data for the development of new and better models that could protect humans on the ground and satellites in space.