GeoTalk: Dr Aikaterini Radioti

GeoTalk, featuring short interviews with geoscientists about their research, continues this month with a Q&A with Dr Aikaterini Radioti (University of Liège) who tells us about her work on auroras in Jupiter and Saturn. If you’d like to suggest a scientist for an interview, please contact Bárbara Ferreira.

Dr Aikaterini Radioti at work

First, could you introduce yourself and let us know a bit about your current research activities? I was born in Ptolemaida, Greece, in 1980. I studied Physics in the Aristotle University of Thessaloniki. I obtained my Ph.D. in Geophysics at the Max-Planck-Institute for Solar System Research (MPS) in Germany. During my Ph.D., I studied the magnetosphere of Jupiter by analyzing data from the Galileo spacecraft which was in orbit around the giant planet for eight years. After a short post-doc at MPS, I was offered a post-doctoral position in the Laboratory of Planetary and Atmospheric Physics at the University of Liège in Belgium, where I investigated the aurora at Jupiter and its relation to the Jovian magnetosphere. I combined remote auroral data from the Hubble Space Telescope with in-situ magnetospheric measurements in order to investigate the coupling between the ionosphere and the magnetosphere (ionospheric-magnetospheric coupling) at Jupiter. For the past three years, I have held a research associate position (Chargé de Recherches, FNRS) in the University of Liège. Recently, my research activities have been extended beyond Jupiter. I have started exploring the auroral emissions at another giant planet, Saturn, based on auroral data from the Ultraviolet Imaging Spectrograph (UVIS) on board of Cassini, a spacecraft which has been orbiting Saturn since 2004. What can your work tell us about the magnetic field and atmosphere of the giant planets? The investigation of planetary auroral emissions plays a key role in solar system research. The auroral activity is the visible signature of a long chain of interactions between a planet, its atmosphere, its moons and rings, the interplanetary space, and the Sun. Thus the study of the auroral emissions gives us a picture of the processes taking place in the magnetosphere, the magnetic field configuration, and the ionosphere. My research work focuses on the investigation of the ionospheric-magnetospheric coupling associated with certain processes taking place at the giant planets’ magnetospheres, such as corotation breakdown of the plasma (where layers of the magnetosphere do not all rotate at the same speed), magnetic reconnection, and plasma injections. By studying the auroral emissions related to the reconnection process and plasma injections, we learn about the frequency of the process, its origin and triggering mechanism, i.e., whether it is solar-wind or internally (mass-loading) driven. The auroral emissions related to corotation breakdown at Jupiter give us information about the plasma distribution in the magnetosphere at various local times, the influence of the solar wind on the magnetospheric convection, and the variations of the ionospheric conductivity. Finally, studying the auroral signatures of certain processes, in combination with the magnetospheric measurements, we can investigate the mechanisms that create auroral emissions (such as electron acceleration by field-aligned currents or electron scattering by whistler waves). Earlier this year, you received an EGU Arne Richter Award for Outstanding Young Scientists for your “remarkable work in the field of auroral dynamics of Jupiter and Saturn”. Could you summarise the research you have done in this area? My research focuses on the auroral dynamics of Jupiter and Saturn. For my scientific work I combined remote auroral and in-situ magnetospheric data, and I developed and applied theoretical approaches on ionospheric-magnetospheric coupling. I mainly studied the ionospheric signatures of magnetic reconnection, plasma injections, and corotation breakdown of the plasma. I showed that ejected plasma flow during magnetic reconnection in Jupiter’s tail couples with the ionosphere and creates periodic auroral emissions. At Saturn, magnetic reconnection in the flank of the magnetopause creates auroral emissions at the end of the ionospheric footprint of the newly opened magnetic field lines. By studying the auroral emissions associated with corotation breakdown, I demonstrated that solar wind-driven magnetospheric convection accounts for a regular discontinuity feature observed close to magnetic noon in the Jovian main auroral oval. Finally my research work suggested that energetic particle injections in the magnetosphere of Saturn could create transient aurora, through electron scattering or by electric currents flowing along the boundary of the injected cloud. You have been involved in Europlanet, an EU project that lists outreach activities in the planetary sciences as one of its main goals. How important do you think it is for researchers to communicate their findings with the wider public? In the framework of Europlanet, I contributed to the organization of three Europlanet workshops (2008, 2010, and 2012) under the financial support of the Europlanet NA1 and NA2 networking activities. We were a group of 30 participants, specialists on the auroral emissions at different wavelength and the associated magnetospheric processes. These workshops have been a great success and one of them was even included in the Europlanet Newsletter as a highlight of the 2010 year’s NA1 activities. Apart from supporting scientific communication between researchers, Europlanet promotes the communication of science to the wider public. Communicating science to the public plays a vital role for the researchers and science itself. Science outreach can help reverse negative attitudes and spark interest and enthusiasm. It creates awareness of the importance of research to the society and the community appreciates your profession and institution. As a result, the communities are encouraged to support science education. Scientists should not restrict themselves to sharing scientific information with their colleagues and publishing their work to scientific journals. Their scientific role does not end in their laboratories or classrooms. They should be educated and prepared for communication with a wider public. After all, they often seek financial support from the wider public for their research. Last but not the least, what are your future research plans? In the near future, I aim to continue working on the ionospheric-magnetospheric coupling and the auroral emissions. For the next couple of years my work will be focused on the auroral dynamics of Saturn, an area of research that has not been well investigated yet. I aim to use the large and rich auroral dataset from the UVIS instrument onboard the Cassini spacecraft. Particularly, I aim to compare the various auroral components with those observed at Earth and Jupiter in order to address the key question whether Saturn’s aurora is similar to Earth’s or Jupiter’s, or a case of its own. On top of that, Juno, a mission to Jupiter, is expected to reach the planet on July 2016. Juno will visit Jupiter’s magnetosphere near the planet’s poles and we will have access to particle and plasma wave measurements in addition to ultraviolet and near-infrared spectral images. Such conjugated observations at the planet’s polar region play a key role in studying auroral emissions as well as the processes involved, and will help us investigate how the planet’s enormous magnetic field generates the aurora.

Bárbara Ferreira was the Media and Communications Manager of the European Geosciences Union from 2011 to 2019. Bárbara has also worked as a science writer specialising in astrophysics and space sciences, producing articles for the European Space Agency and others on a freelance basis. She has a PhD in astrophysics from the University of Cambridge.

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