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2019 Edward Appleton Medal and Prize

Professor Cathryn Mitchell for pioneering research in tomography and data assimilation revealing a completely new perspective on the Earth's ionosphere in response to extreme space weather.

Professor Cathryn Mitchell

Cathryn Mitchell is the Academic Director of the University of Bath Doctoral College. She is nominated for her pioneering research revealing a completely new perspective on the Earth's ionospheric dynamics in response to extreme space weather events.

Mitchell innovated a completely new Earth observation technique by adapting medical tomography to image the Earth's ionosphere, thus revealing the dynamics of the near-Earth space environment. Her use of Global Positioning System satellite signals as a source for space weather tomography, through a new time-dependent mathematical inversion algorithm, has given us the first global-scale view of the ionosphere in response to space weather storms.

Mitchell's research has fundamentally changed our understanding of the Earth's ionosphere, revealing dynamic processes driven by magnetospheric electric fields causing enormous plasma enhancements and uplifts and has led on to ionospheric data assimilation and forecasting.

Her deep field experimental work to collect tomographic radio signals has taken her to the Arctic and the Antarctic and has changed our understanding of the relationship between plasma density irregularities and optical aurora and led to the discovery of disruptive radio propagation effects on satellite signals used for navigation and timing.

Mitchell's research has practical impacts improving the accuracy and reliability of satellite navigation systems. She currently holds NERC Knowledge Exchange Fellowship and has recently acted in advisory roles for UK and USA government bodies and for ESA. In 2015 she was invited by Dstl to be the scientific advisor for a UK Government Scientific Advisory Group for Emergencies exercise to test UK infrastructure resilience to a large space solar storm. This included assessment of threats to  satellite navigation and communication, aviation, power, financial services, road and rail.

She has published over 100 journal papers and her tomography algorithms are licensed to other research organisations nationally and internationally. She continues to pioneer new observation techniques, this year producing the first ever single-frequency Geostationary GPS ionospheric measurements. Mitchell's innovations in tomographic imaging have crossed traditional discipline boundaries and are now applied in other fields including medical imaging, nuclear imaging and cosmic-ray muon tomography.

Read about our Silver Subject Medals.