Leaky Radiation Belts

  • Released Wednesday, March 15th, 2017
  • Updated Tuesday, November 14th, 2023 at 12:09AM
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Since their discovery at the dawn of the Space Age, Earth's radiation belts continue to reveal new complex structures and behaviors.

During a particularly intense event in late June 2015, the inner edge of the region of trapped electrons moved closer to Earth. The electrons of interest had energies in excess of a million electron volts (Wikipedia). As the region retreated outward, it left behind a population of high-energy electrons forming another radiation belt inside the L=2 shell (The 'L-shell' value identifies a field line in a magnetic dipole. The numerical value corresponds to the furthest distance from Earth in Earth radii, in this case two Earth radii). This flux of high-energy electrons persisted considerably longer than expected, the relativistic electrons slowly leaking away. It took over a year for the relativistic electron flux in the belt to decline below the level of detectability for the instruments on the Van Allen Probes.

The 3-dimensional radiation belt model in the visualizations above was constructed by propagating electron flux measurements, corresponding to a given time and distance from Earth measured by the Van Allen Probes, along a 3-dimensional structure of magnetic dipole field lines.


Please give credit for this item to:
NASA's Scientific Visualization Studio


This visualization is related to the following missions:

Datasets used in this visualization

  • Van Allen Probes ECT

    ID: 828
    Observed Data Collected with Energetic Particle, Composition, and Thermal Plasma Suite University of New Hampshire 2015-03-01 to 2016-06-30

Note: While we identify the data sets used in these visualizations, we do not store any further details, nor the data sets themselves on our site.