More on the “Zebra Stripes”

My very first post on this website was on the “zebra stripes”, an intriguing feature present in electron energy spectrograms measured in the Earth’s inner radiation belt and slot region. A lot of research remains to be done on this topic, and I am happy to share some of the most recent findings.

1) Zebra stripes are usually created during substorm onset, a time at which prompt penetration electric fields are present in the plasmasphere.
For more info on the method and findings, there is now JGR Space Physics article on this! [access here]

2) The zebra stripe pattern can be disrupted and inversed in the slot region.
The first observations of this remarkable feature are presented and interpreted in our latest Geophysical Research Letter [access here]

In summary: the “zebra stripes” visible at Earth (and also Saturn!) are an exciting research topic containing a wealth of information on trapped particle dynamics.

More to come! Feedback, questions, collaborations welcome.

Two Works among the Top Downloaded Papers in JGR Space Physics 2018-2019

Sharing a bit of good news in these strange times! Recently Wiley informed me that that two of my latest works were among the top 10 % downloaded papers published in Journal of Geophysical Research: Space Physics between January 2018 and December 2019.

Interestingly, both papers provide brief reviews on a particular topic in radiation belt research:
1) adiabatic invariant theory, and
2) radial diffusion

The first paper is entitled “Coordinates For Representing Radiation Belt Particle Flux”. It is authored by Juan G. Roederer and myself. It insists on the importance of adiabatic invariant theory when it comes to analyzing measured particle fluxes, and it provides a brief review on the history of radiation belt parameterization.

The second paper, entitled “Analytic Expressions for Radial Diffusion”, discusses existing theoretical formulas to quantify radial diffusion. Unfortunately, there were many unexplained errors during the production process, and many misprints were present in the first published version of the article. The issue is now fixed.  All of this is to say: make sure you have downloaded the latest version of the paper!

I prepared the latter article while I was working with Peter Kollmann and others on a big scientific review on “Radial Diffusion at Earth and Beyond” that is now published in Space Science Reviews. Don’t hesitate to have a look if you are interested in learning more about adiabatic theory and radial diffusion! You can also navigate the website and scroll through the various seminar slides on the topic.

Thanks again for your interest in the works! and thanks all for the clicks!


A Scientific Review on Radiation Belt Radial Diffusion

“Synthesis is an important task in science, because it can often lead to a paradigm change” Akasofu, S.-I., 2007, preface of the second edition of “Exploring the Secrets of the Aurora”


At the very beginning of my phD studies, my supervisor asked me to work on radiation belt radial diffusion. For months, I felt bewildered.

It took me a lot of time to find clarifications, and to answer my own questions – Why is the process diffusive? What are the drivers of this diffusion? What ingredients does one need to quantify the process?

Because radial diffusion is one of the oldest research topics of radiation belt science, its understanding evolved over time. I think that is one of the reasons why this concept can be so difficult to grasp.

As time went on, I realized that I was far from the only one facing this radial diffusion challenge. That is what motivated the writing of this review.

A Team Project

I was excited at the idea of writing a review. Yet, I could not do this on my own.

I want to say THANK YOU to Sarah, Adnane, and Peter, the early career researchers who agreed to get involved with this project. They all dedicated countless hours to help. I am also grateful to all the experienced researchers who answered my emails and helped me submit the review. To all, thanks for caring!


I hope that this review will be useful for our community … and perhaps – who knows! – lead to a paradigm shift.

So please go ahead, give it a try, and let me know what you think! All significant contributions will be acknowledged in the revised version of the manuscript – currently under review for publication in Space Science Reviews -. Merci 🙂

[Access here]