Inner Van Allan Zebra Stripes

Inner Van Allen Zebra Stripes

NASA is good at concocting catchy and distracting headlines for their press releases.

This week was no exception when they delivered the “zebra stripes” and “zebra patterns” distractions for the gormless and gullible.

Scientists have discovered a new, persistent structure in one of two radiation belts surrounding Earth. NASA’s twin Van Allen Probes spacecraft have shown that high-energy electrons in the inner radiation belt display a persistent pattern that resembles slanted zebra stripes.

NASA’s Van Allen Probes Reveal Zebra Stripes in Space

“It is because of the unprecedented high energy and temporal resolution of our energetic particle experiment, RBSPICE, that we now understand that the inner belt electrons are, in fact, always organized in zebra patterns,” said Aleksandr Ukhorskiy of the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Md., co-investigator on RBSPICE and lead author of the paper.

NASA Spacecraft Reveal New “Zebra Stripes” Structure in Earth’s Inner Radiation Belt

While the audience are digesting this distraction they quickly slip in some amazing statements.

Surprisingly, this structure is produced by the slow rotation of Earth, previously considered incapable of affecting the motion of radiation belt particles, which have velocities approaching the speed of light.

NASA’s Van Allen Probes Reveal Zebra Stripes in Space

“Furthermore, our modelling clearly identifies Earth’s rotation as the mechanism creating these patterns. It is truly humbling, as a theoretician, to see how quickly new data can change our understanding of physical properties.”

NASA Spacecraft Reveal New “Zebra Stripes” Structure in Earth’s Inner Radiation Belt

It’s just amazing how a new “model” can transform something that was “previously considered incapable” into something that is now claimed to be the driving “mechanism”.

The elephant in the room they are trying to wiggle round [aka model] is the phenomena called atmospheric corotation whereby the Earth’s atmosphere corotates with the planet.

The settled science regarding atmospheric corotation is that the surface of the rotating Earth causes the atmosphere to corotate with the planetary surface.

Unfortunately, for the mainstream, the science of viscous fluids dictates that atmospheric corotation must be driven externally.

Basically, the Earth’s atmosphere would need to be as thick as pitch to enable the Earth’s surface to transfer sufficient momentum into the atmosphere so that it could corotate with the planet [in the short term].

Additionally, any momentum transferred from the surface into the Earth’s atmosphere has limited potential for upward propagation because the [already low] viscosity of the atmosphere will decrease as the atmospheric temperatures decease with altitude.

If you have enjoyed the cooling “breeze” generated by a rotary fan then you probably know the “breeze” dissipates with distance.

If you have looked at the design of rotary fans and propellers you should understand that a solid sphere is a very inefficient mechanism for transferring momentum.

If you have studied aerodynamics you should appreciate that the momentum of rotating air [wake turbulence] is usually dissipated within a minute.

Therefore, the Earth’s surface cannot drive “bottom up” atmospheric corotation.

They tenaciously cling to this misguided belief even though they know the atmosphere is a “viscous fluid” that can be “stretched and folded” electromagnetically.

Because of the tilt in Earth’s magnetic field axis, the planet’s rotation generates an oscillating, weak electric field that permeates through the entire inner radiation belt.

To understand how that field affects the electrons, Ukhorskiy suggested an analogy: “If the inner belt electron populations are viewed as a viscous fluid, these global oscillations slowly stretch and fold that fluid, much like taffy is stretched and folded in a candy store machine,” he said.

This stretching and folding process results in the striped pattern observed across the entire inner electron belt, extending from above Earth’s atmosphere (about 500 miles, or 800 kilometers, above the planet’s surface) up to roughly 8,000 miles (13,000 kilometers).

NASA’s Van Allen Probes Reveal Zebra Stripes in Space

Helpfully, NASA provides some contextual information regarding the Van Allen “radiation belts”.

The radiation belts are dynamic doughnut-shaped regions around our planet, extending high above the atmosphere, made up of high-energy particles, both electrons and charged particles called ions, which are trapped by Earth’s magnetic field.

Radiation levels across the belts are affected by solar activity that causes energy and particles to flow into near-Earth space.

During active times, radiation levels can dramatically increase, which can create hazardous space weather conditions that harm orbiting spacecraft and endanger humans in space.

It is the goal of the Van Allen Probes mission to understand how and why radiation levels in the belts change with time.

However, NASA seems less than enthusiastic about highlighting the electrical nature of the Van Allen “radiation belts”.

The inner belt, consisting mainly of energetic protons…
The outer belt consists mainly of electrons.

Van Allen Belts

NASA also seems less than enthusiastic about highlighting how this all fits together with the “zebra stripes” that were observed on the 1st January 2004.

2004 Van Allen Belts

Sadly, the audience is left to guess where [and how] the new illustrations fit within this wider context of the Van Allen “radiation belts”.

Published Illustrations

The left hand “zebra stripes” illustration is very intriguing because it shows the “energetic electron spectra” in the inner “radiation belt” which [we are told] contains mainly “energetic protons”.

The horizontal scale is labelled L [Earth Radii] which implies the scale is based upon the concept of L-shells where L = 1 represents the surface of the planet.

The L-shell, L-value, or McIlwain L-parameter (after Carl McIlwain) is a parameter describing a particular set of planetary magnetic field lines.

Colloquially, L-value often describes the set of magnetic field lines which cross the Earth’s magnetic equator at a number of Earth-radii equal to the L-value.

For example, “L=2” describes the set of the Earth’s magnetic field lines which cross the Earth’s magnetic equator two earth radii from the center of the Earth.

L-shell parameters can also describe the magnetic fields of other planets.

In such cases, the parameter is renormalized for that planet’s radius and magnetic field model.

Although L-value is formally defined in terms of the Earth’s true instantaneous magnetic field (or a high-order model like IGRF), it is often used to give a general picture of magnetic phenomena near the Earth, in which case it can be approximated using the dipole model of the Earth’s magnetic field.


Additionally, the shape of the “zebra stripes” illustration does not match the overall shape of the inner Van Allen cross-section that appears in the context diagram.

Therefore, it seems reasonable to assume that the “zebra stripes” illustration is only the top half of the cross-section and that the overall cross section might look something like this.

Zebra stripes

However, there is method in the madness because the mainstream settled science of magnetic field lines does not accord with the reality of magnetic field lines [as illustrated below – this can easily establish by probing around a magnet with a sewing needle].

Magnetic Lines of Force

Black and White Bloch

With their right hand swirling “animation” illustration [again] we appear to be getting only the top half of something – presumably the cross-section section of the inner Van Allen radiation belt.

As material moves through Earth’s radiation belts, it can fold over on itself like taffy, creating zebra stripes of electrons with different energies.
Credit: APL

Intriguingly, this swirling “animation” illustration suggests that the structure of the inner Van Allan belt [when viewed side on] may display patterns that are very similar to those observed on Jupiter.

Inner Van Allen Belt Wave Train

Gallery | This entry was posted in Astrophysics, Earth, Science, Solar System, Vortices. Bookmark the permalink.

2 Responses to Inner Van Allan Zebra Stripes

  1. J Martin says:

    ~”It is truly humbling, as a theoretician, to see how quickly new data can change our understanding of physical properties.”

    Can’t see the co2 high priests taking that one on board any time soon.

  2. Pingback: Couette Flow 4: Taylor Vortices | MalagaBay

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