Dark Aurora and Solar Tufts

[jacmac]

Sorry if this has been talked about elsewhere, but I have not seen it.

I recently read about Dark Aurora. Apparently dark areas in auroras are found where the flow of the charged particles is in reverse to the normal downward flow of the main aurora current. Isn't this very similar to the relatively thin dark areas around the solar tufts. I read somewhere that the flow was reversed there also. Sorry I don't have the time to find all the references, but Googling "dark aurora" gets you there.

It seems to me that these two observations are similar electrical events given that the aurora is in glow mode and the sun is in arc mode. Is this correct?

Jack

[jacmac]

Sorry for not posting a link in the above post. Here is what I was referring to.

http://sci.esa.int/science-e/www/object ... ctid=29100

There are dark areas in some aurora where the current flows in reverse.

[jacmac]

Now I remember. It is called BLACK AURORA. It is item #12 on this site.

http://odin.gi.alaska.edu/FAQ/#black

I need to do a better job of not being in a hurry when making these posts. Sorry people.

jack

[solrey]

Hey now jacmac. No worries mate, that's a great find. I keep an eye out for evidence of this:

The Cluster data show that the black aurora occurs where there are holes in the ionosphere(*), the part of the upper atmosphere where aurorae are created. Here, the particles that make up the ionosphere are shooting upwards into space inside regions known as positively charged electric potential structures.

Aligned like a string of pearls flying 100 seconds apart, the first three spacecraft (Rumba, Salsa and Samba) detected an increase in the energy of the upward-moving electrons, coinciding with an increase in the electric field that was accelerating the electrons, and a stable electric current. However, the electric field had vanished and no evidence of a structure could be seen by the time the fourth spacecraft (Tango) flew over the aurora.

Similar results were obtained from a crossing of the southern hemisphere auroral zone on 14 February. Once again, the electric field increased steadily in strength, but the electric current stayed constant as the quartet sped overhead.

The "holes" in the ionosphere they refer to are a "mobile charge carrier" within the charge sheaths of a double layer. A "positively charged potential structure" is one of several terms for the same thing. They effectively perform the same function as the impurities or "defects" that make a semiconductor work the way they do.

This might be the first observational data that confirms theory and simulations regarding a double layer associated with auroral activity.

Double layers and ion phase-space holes in the auroral upward-current region.

The dynamic evolution of the boundary between the ionosphere and auroral cavity is studied using 1D and 2D kinetic Vlasov simulations. The initial distributions of three singly ionized species (H+, O+, e-) are determined from space-based observations on both sides of an inferred strong double layer. The kinetic simulations reproduce features of parallel electric fields, electron distributions, ion distributions, and wave turbulence seen in satellite observations in the auroral upward-current region and, for the first time, demonstrate that auroral acceleration can be driven by a parallel electric field supported, in part, by a quasistable, strong double layer. In addition, the simulations verify that the streaming interaction between accelerated O+ and H+ populations continuously replenished by the double layer provides the free energy for the persistent formation of ion phase-space holes.

Formation of double layers and electron holes in a current-driven space plasma.

Kinetic 1D simulations reveal that a weak density depression in a current-carrying plasma can lead to the formation of a strong potential ramp (double layer). The ramp and plasma turbulence it creates share many features with recent particle and field measurements in the auroral ionosphere. An electron beam accelerated by the ramp produces a series of propagating electron phase-space holes via a spatial two-stream instability. Electron heating associated with the formation and merging of these holes is found to influence the subsequent evolution of the potential ramp.

Electron holes as a common feature of double-layer-driven plasma waves

Using a Vlasov code for simulating fully nonlinear behavior of a plasma driven by an applied potential drop, it is shown that fast solitary potential pulses in the form of electron holes are a common feature of the high potential side of a strong double layer. Temporal and spatial features of the electron holes seen in the simulations are compared against the measurements from FAST. The evolution of the electron beam accelerated by a double layer and that of the plasma on its high potential side generate the suitable conditions for nearly continuously creating fast moving electron holes.

Propagation of electron phase-space holes during the evolution of moving double layers

The propagation of electron phase-space solitary holes is observed experimentally during the evolution of moving double layers. The holes are generated in front of the plasma source just as the rarefaction electron wave pulse reaches it, in good agreement with a simulation.

Experiment, theory, simulation and observation all seem to be in agreement. Chalk up another successful prediction/expectation for EU.

[GaryN]

From the same page, I found this little nugget of gold to add to my treasure chest of EM structures:

Cluster Tunes Into Earth’s Frequency, Pinpoints Location of Auroral Radio Emissions

http://istp.gsfc.nasa.gov/istp/news/0112/fall01agu.html

A 1 Billion watt radio source that is just where my mental EM model says it should be. Cool.

[jacmac]

Solrey, Thanks for the more detailed double layer information.

From my less scientific viewpoint it seems like what is happening in the aurora with the "black" areas, the main visible aurora is down and the black invisible aurora is up, is similar to the solar granule areas where the main current is going up and the lesser or darker boundary areas are going down. The sun is in a much higher energy arc mode while the earth aurora is in a lower energy glow mode. The sun photosphere is like a generating arc while the earth is more of a recipient at lower energy. Is this why the bright flow is up at the sun and down at the earth, and the darker flow is down at the sun and up at the earth?

The darker aurora at the earth seems to be generally accepted as an electric event. Is the similarity to the sun event further evidence that the sun is an electric event?

I'll check out the Auroral radio emissions later thanks GaryN.

[solrey]

It's true that charged particles simultaneously flow in opposite directions in plasma. Positive particles in one direction, negative particles in the opposite direction. The same applies to a discharge column like the solar granules. However, I think it's the sunspots that are analogous to the Dark Aurora because sunspots are likely the result of "charged electric potential holes" in the double layer of the chromosphere.

I'm learning that those "holes" are just as important as the double layers themselves in the dynamics of plasma.

[jjohnson]

If planets with magnetic fields and auroras are very radio "noisy"at billion-watt power levels, at what frequency bands are SETI researches being conducted (other than at HI)? Could naturally intense radio events and radio-shielding atmospheres or ionospheres degrade potential signals to the degree that all we are likely to be able to observe from LY away would be the noise component of radio emissions? This is one of those questions that implicitly asks not only about what part of the electromagnetic spectrum are we searching, and why, but how about frequency modulated radio (FM) - a much less "natural" phenomenon? Where in the frequency band are the radio "holes" in various types of atmospheres, and what are the effects of ionospheres on their ability to transmit signals from technological life forms into space?

Since we can transmit and receive radio signals from spacecraft (at extremely low signal-to-noise ratios!) there are obviously frequencies at which reception and communication are most efficient.

The more we learn about the eletromagnetic phenomena existing here on our own planet, the better we can organize and conduct SETI types of experiments in the ambient E/M universe.

[Jarvamundo]

Good points...comments ring true with the "space probe design problem" when IEEE-ers are not included in the initial design of experiments (Deep impact's blinding FLAAASH!) as mentioned here on the "photos of the suns poles" thread. Very valid.

Although... E.T's probably still waiting for us to pick up the scalar phone.

[Jarvamundo]

Although... E.T's probably still waiting for us to pick up the scalar phone.

Re: Scalar Phone - weird... just head the same from Siggy's Wallace Thornhill radio talk post.

http://www.youtube.com/watch?v=-TPnydh9yYs&NR=1 1minute:30sec into it...

"It is the only form of signaling that isnt sheilded by plasma sheaths and double layers in space"

"Why haven't we been able to hear from E.T (SETI). I can tell you why, we are using the wrong signaling technique"

rock on Wal... rock on.

[junglelord]

Tesla said that only longitudinal waves travel in the vacuum...now you know why.

"It is the only form of signaling that isnt sheilded by plasma sheaths and double layers in space"

[jacmac]

To the list of articles from Solrey above I would add this. It is not directly to do with double layers but "very interesting".
It is # 29 on the list of additional articles at the ScienceDirect site.

http://www.sciencedirect.com/science?_o ... 015&view=f

Self-organization scenario acting as physical basis of intelligent complex systems created in laboratory.
Chaos, Solitons & Fractals, Volume 30, Issue 1, October 2006, Pages 125-132
Erzilia Lozneanu, Mircea Sanduloviciu

Abstract:
The recognition of limits in the tendency to miniaturize the so-called self-organizing devices inspired scientists to seek inspiration from living organisms that operate with functional elements that employ thermal energy exploiting quantum phenomena. Here we show how such operations are performed by a complex space charge configuration emerged by self-organization in plasma. Endowed with a special kind of memory, the complexity is able to ensure its survival in a metastable state performing the operations “learned” during its emergence by self-organization. Possessing memory, the complexity works as an intelligent system able to evolve under suitable environmental conditions.

Perhaps a more scientifically adept member of the EU community might have something to say about this?

Jack

[junglelord]

I agree with that position.
I came to that conclusion myself about 15 years ago.
Self orgnaization and memory of the system, which I equated as Energy = Information.


The whole event in my mind, led to a fractal viewpoint of the universe.

[Solar]

To the list of articles from Solrey above I would add this. It is not directly to do with double layers but "very interesting".
It is # 29 on the list of additional articles at the ScienceDirect site.

http://www.sciencedirect.com/science?_o ... 015&view=f

Self-organization scenario acting as physical basis of intelligent complex systems created in laboratory.
Chaos, Solitons & Fractals, Volume 30, Issue 1, October 2006, Pages 125-132
Erzilia Lozneanu, Mircea Sanduloviciu

It speaks to the scalable "self-organizing" aspects electro-plasma dynamics. The same as can be seen via this article on the larger scale:

"Hot Gas in Space Mimics Life"

These guys simply need to learn the history behind the origin of the term "plasma" and the work of Irving Langmuir, H. Alfven et al:

Irving Langmuir (1881-1957), USA

Langmuir (1881-1957) was the first to use the term 'Plasma' in 1927, borrowing it from Blood Plasma to describe the almost life-like and self-organising behaviours of a plasma when in the presence of electrical currents and magnetic fields.

He discovered Plasma Sheathes, now called Double Layers, having observed the electrons and ions of a plasma separating during experimentation. DLs are one of the most important features of plasma behaviour.

He also defined and explained the term 'valence' as part of his description of the atom. Few textbooks, however, recognise the influence that Langmuir had on the development of our understanding of the nature of the atom.

He became the first 'non-academic' chemist to receive the Nobel Prize, an accomplishment he realised in 1932. Langmuir probes, which can be used in space, are named after him. - PlasmaCosmology

Langmuir was the first to coin the term plasma (in 1923), borrowing the term from medical science, to describe the lifelike state he observed in the laboratory. He also the first to discover 'double sheathes,' now called double layers, as the plasma electrons and ions separated in his glass tubes. - Plasma Science

The parameters of plasmas, including their spatial and temporal extent, vary by many orders of magnitude. Nevertheless, there are significant similarities in the behaviors of apparently disparate plasmas. It is not only of theoretical interest to understand the scaling of plasma behavior, it also allows the results of laboratory experiments to be applied to larger natural or artificial plasmas of interest. - Plasma Scaling

At best they're simply providing more detail and perhaps a broader range of the same relationship noticed by Langmuir with blood plasma.

[solrey]

Add this one to the collection.

From plasma crystals and helical structures towards inorganic living matter

Abstract. Complex plasmas may naturally self-organize themselves into stable interacting helical structures that exhibit features normally attributed to organic living matter. The self-organization is based on non-trivial physical mechanisms of plasma interactions involving over-screening of plasma polarization. As a result, each helical string composed of solid microparticles is topologically and dynamically controlled by plasma fluxes leading to particle charging and over-screening, the latter providing attraction even among helical strings of the same charge sign. These interacting complex structures exhibit thermodynamic and evolutionary features thought to be peculiar only to living matter such as bifurcations that serve as `memory marks', self-duplication, metabolic rates in a thermodynamically open system, and non-Hamiltonian dynamics. We examine the salient features of this new complex `state of soft matter' in light of the autonomy, evolution, progenity and autopoiesis principles used to define life. It is concluded that complex self-organized plasma structures exhibit all the necessary properties to qualify them as candidates for inorganic living matter that may exist in space provided certain conditions allow them to evolve naturally.

Effects of plasma fluxes lead to gravitation-like instabilities with an effective gravitational constant GeffapproxZd2e2|ψminmd2. For a dust size aapprox3 μm, a mass density of the dust material of 2g cm–2, Zdapprox103 and |ψmin|approx10–4, the effective gravitational constant Geff is approximately 6×104 cgs which is 1012 times larger than the usual gravitational constant G = 6.7×10–8 cqs. The effective Jeans length of this instability has the size of order rd. The effective gravity affects only dust grains and therefore plasmas can be influenced by this attraction only through their interactions with the grains. The new effective instability of a dusty plasma leads to structurization of dust clouds similar to the effects caused by the usual gravitational instability.