EGU22-8799
https://doi.org/10.5194/egusphere-egu22-8799
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

On the Similarity and Repeatability of Fast Magnetopause Shadowing Loss

Leonid Olifer1, Ian Mann1, Louis Ozeke1, Seth Claudepierre2, Daniel Baker3, and Harlan Spence4
Leonid Olifer et al.
  • 1University of Alberta, Department of Physics, Edmonton, Canada (olifer@ualberta.ca)
  • 2Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA, USA
  • 3Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, USA
  • 4Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA

Properly characterizing fast relativistic electron losses in the terrestrial Van Allen belts remains a significant challenge for accurately simulating their dynamics. In particular, magnetopause shadowing losses can deplete the radiation belt within hours or even minutes but can have long-lasting impacts on the subsequent belt dynamics. By statistically analyzing seven years of data from the entire Van Allen Probes mission in the context of the last closed drift shell, here we show how these losses are much more organized and predictable than previously thought. Once magnetic storm electron dynamics are properly analyzed in terms of the location of the last closed drift shell, not only is the loss shown to be repeatable but its energy-dependent spatio-temporal evolution is also revealed to follow a very similar pattern from storm to storm. Employing an energy-dependent ULF wave radial diffusion model, we further show for the first time how the similar and repeatable fractional loss of the pre-storm electron population in each storm can be reproduced and explained. Empirical characterization of this loss may open a pathway toward improved radiation belt specification and forecast models. This is especially important since underestimates of loss can also create unrealistic sources in models, creating phantom electron radiation and leading to the prediction of an overly harsh radiation environment.

How to cite: Olifer, L., Mann, I., Ozeke, L., Claudepierre, S., Baker, D., and Spence, H.: On the Similarity and Repeatability of Fast Magnetopause Shadowing Loss, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8799, https://doi.org/10.5194/egusphere-egu22-8799, 2022.

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