Recently I was asked to summarize my career and highlight how the Van Allen Probes have shaped it to date. Here is my reply:
3 Research Highlights of Solène Lejosne’s Early Career
1. Offering New Visibility on Plasma Transport in Subauroral Geospace in the Form of a Unique Database of Electric Drift Measurements (ExB/B2)
Together with Pr. Mozer, S. Lejosne has pioneered techniques to analyze RBSP-EFW data close to perigee. She demonstrated that the instruments onboard the Van Allen Probes were accurate enough to deliver reliable electric field measurements even very close to Earth (below 3 Earth radii). This database provides much-needed ground truth in a region of space historically deprived from in-situ electric field measurements due to the technical challenge that this represents. Her studies underscore the importance of magnetosphere-ionosphere coupling in the subauroral region. It often consists of examining features of the electric drift data (SAPS, ionosphere wind dynamo, disturbance dynamo, prompt penetration electric fields), and studying their consequences in terms of trapped particle drift dynamics.
2. Pursuing Pioneering Research on the Earth’s “Zebra Stripes”
The Van Allen Probes mission has provided unprecedented amounts of high quality data on near equatorial electric fields and energetic particle fluxes, enabling systematic empirical analyses of the “zebra stripes”. After teaming with Pr. J.G. Roederer to propose a theory for zebra stripe generation, S. Lejosne designed an algorithm to automatically detect and analyze the multitude of “zebra stripe” patterns observed by the RBSPICE instruments onboard the Van Allen Probes. The resulting statistical analysis has provided experimental information on the geomagnetic conditions usually associated with the generation, structure and evolution of the “zebra stripes”. Together with Pr. Mozer, she also reported and interpreted the 1st observations of zebra stripe pattern inversions in the Earth’s slot region.
3. Rejuvenating Radial Diffusion Research
S. Lejosne dedicated her ph.D studies to radial diffusion in the Earth’s radiation belts. To celebrate the 60th anniversary of radial diffusion research in 2019, she worked with an international team of early career researchers to write a scientific review on “Radiation Belt Radial Diffusion at Earth and Beyond” (now published in Space Science Reviews). She has highlighted the necessity to question several assumptions underlying current radial diffusion models. She has also suggested new approaches to radial diffusion quantifications. Her most recent work includes a 20 year time series of electromagnetic radial diffusion coefficients with a one-minute time resolution, based on an analysis of the solar wind immediate time history. Future work includes analyzing Van Allen Probes field and particle data to quantify electrostatic radial diffusion in the Earth’s inner radiation belt and slot region.
I have prepared a short (< 5 min) video presentation that walks you through it all. You can check it out here!