How volcanic lightning is helping to demystify the Earth's plasmasphere

Earth
A composite image of the Western hemisphere of the Earth. Credit: NASA

At the height of the First World War, in the trenches, German physicist Heinrich Barkhausen was eavesdropping on Allied telephone conversations. Every now and again, the Allied communications were drowned out by some strange sounds. The soldiers dubbed them "whistlers" because they sounded similar to shells flying overhead.

Barkhausen concluded that these whistler waves were caused by an atmospheric phenomenon but the true source was not identified until the 1950s, when scientists eventually found that whistlers are produced by bolts of lightning thousands of kilometres away. Once created, these electromagnetic waves are channelled around the world via ducts in the plasmasphere (a region also known as the inner magnetosphere).

In the July 2015 issue of Physics World, a special issue on weird natural phenomena, Ian Randall, a science writer based in New Zealand, investigates how researchers are studying whistler waves triggered by to elucidate the structure of the Earth's plasmasphere, which will eventually help scientists get better at anticipating the impact of .

Lightning creates bursts of very-low-frequency radio waves – known as atmospherics, or "sferics" for short – and these sometimes penetrate the ionosphere and make it into the plasmasphere, where the sferics whizz between hemispheres through ducts of plasma where they become whistler waves.

The passage of whistlers between the hemispheres provides a rare opportunity to investigate the plasmasphere without the need to launch expensive space probes. Better understanding of this near-Earth region of space can help scientists get better at anticipating the impact of space weather events that can endanger astronauts and disrupt both orbiting and ground-based electronic systems.

To elucidate the structure of the plasmasphere, researchers need to feed in a few factors to their model such as the whistler's frequency. The problem is that they also need to know where each whistler enters and leaves the plasmaspheric duct and it is usually impossible to pinpoint the location of a that caused a particular whistler wave – because the original sferic can travel thousands of kilometres before entering a duct.

However, a recording station in Dunedin on New Zealand's South Island provides a unique opportunity: its magnetic conjugate point lies in the Aleutian Islands, a volcanic chain of more than 40 volcanoes in the northern Pacific Ocean.

Like regular lightning, volcanic lightning neutralizes the charge build-up that develops from the generation and separation of charges. Karen Aplin, an atmospheric physicist from the University of Oxford, explains: "Once charge has been generated in a volcanic plume, it is separated by convection, carrying smaller particles upwards, whereas heavier – and often oppositely charged – particles settle under gravity."

Researchers looked at correlations between whistler data in this area and lightning data from prominent, high latitude volcanic eruptions in the Aleutian chain and found the first evidence that volcanoes are able to couple with the inner magnetosphere.

Commenting on this novel discovery, Claire Antel, a physicist from the University of Cape Town in South Africa says: "The improved knowledge of whistler paths increases the fidelity of the plasmaspheric model that makes use of whistler data."

Although this whistler study was very much Earth-based, Mark Golkowski, a plasma-physics expert from the University of Colorado Denver, believes that it has ramifications beyond our planet. "The volcanic-whistler findings support proposed studies to use dust-storm on Mars to probe the weak plasma densities of the planet's upper atmosphere," he says.


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Journal information: Physics World

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Jul 02, 2015
Might be the first reference to the electrical nature of Martian dust storms I've seen in a conventional source -- a question which I believe sources to the Thunderbolts Group's claim on the electrical nature of Martian dust devils and the unexpectedly filamentary nature of Mars' global dust storms.

Jul 03, 2015
How volcanic lightning is helping to demystify the Earth's plasmasphere

"Demystify"? Strange how much of which is electrical, magnetic, or plasma related is "mystical", "magical", and unknown to traditionally trained physicists.

"Once charge has been generated in a volcanic plume, it is separated by convection, carrying smaller particles upwards, whereas heavier – and often oppositely charged – particles settle under gravity."

Didn't have to look far to see how unknown these physics are to an "atmospheric physicist". In Earth's electric field, these charged particles aren't driven by convection and gravity, they respond to electrical forces which are many magnitudes more powerful than these weak (gravity) nearly meaningless forces.


Jul 03, 2015
Thanks, Hannes and cantdrive.

You two are always good for a laugh!

Though sadly it comes at the expense of science.

Jul 03, 2015
And you can always be counted on as a creepy stalker troll.

https://sciencex....5/?v=act

Between you and Cap'n Stupid, I can typically count on at least a couple votes. I just noticed my other stalker is conspicuously absent, barakn only registered one downvote on the linked comments. I hope he is just on vacation and not experiencing any health issues or anything. Being most of my entourage are geriatrics the latter is quite possible. That's how science progresses though, isn't it?

"A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it." Max Planck

BTW, you missed one or two. Try and be a little more thorough please.

Jul 03, 2015


BTW, you missed one or two. Try and be a little more thorough please.


I didn't miss anything, I just didn't vote on your comments in those threads.

Jul 03, 2015
"Demystify"?
@cd
AKA- 1. (tr) to remove the mystery from; make clear... not "subjectively posit opinion based upon fallacious data and religious like clinging to pseudoscience" like eu does
...unknown to traditionally trained physicists
so you are making a claim that all astrophysicists and physicists are ignorant of electrical and plasma phenomenon based upon a pop-sci article in a science clearing house site?
and you wonder why you are considered a trolling pseudoscience acolyte?
In Earth's electric field, these charged particles aren't driven by convection and gravity
nice claim: where is the empirical evidence (preferably in the form of a validated study published in a reputable journal with peer review... not thunderbutts, which has NO peer review and is the promotion site of pseudoscience SCAM artists)

feel free to link actual validated studies... if you can find them

Jul 03, 2015
Between you and Cap'n... count on at least a couple votes
@cd
when you frequent the same articles that also interest me and then post pseudoscience like eu, you can expect to be downvoted for it
especially when you can't support your claims with evidence other than your typical "looks like a duck" hand waving posts (to borrow a phrase from JeanTate - thanks Jean)
"A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it." Max Planck
and might i state again: just because this is how the world worked in the past doesn't mean it is how it still operates. you make this same claim with your God-like worshiping of alfven... AND you can be proven wrong with the simple BICEP2 results

SCIENCE works by weeding out pseudoscience like yours and proving (or falsifying) a claim

Jul 03, 2015
Might be the first reference to the electrical nature of Martian dust storms I've seen in a conventional source
@hannes
then you obviously are NOT reading actual science or their related pages, like NASA or other publications

see also: http://www.nasa.g...ust.html

http://phys.org/n...ars.html

i will also point out, AGAIN, that the eu (and cd especially) have yet to be able to show evidence supporting their claims (especially in that last link)

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