E- & Ions Deflection by Earth's Magnetic Field

[darkdave3000]

TL;DR Summary

For distant solar wind particles interacting weakly with Earth's magnetic field...

1. Electrons left of Earth fly left and away from Earth.

2. Electrons right of Earth veer left toward Earth

3. Ions right of Earth veer right and away from Earth.

4. Ions left of Earth veer right toward Earth.

True or false?

Do solar wind electrons turn left and positively charged ions turn right if they are interacting weakly due to long distance with Earth's magnetic field and fail to complete a loop for the electrons that are on the left of Earth and ions on the right? I assume electrons on the right and ions on the left will veer toward the Earth to be trapped in the magnetic field and spiral to the poles instead of deflecting away.

That is if they are left and right of the Earth and not North and/or South (above or below it). And interacting weakly with the magnetic field because their far away but either flying into the orbital path (if their electrons) of the Earth or to its previous positions on the right (if their positive ions) and far enough not to twirl into the north and south poles.

Assume left and right to mean left and right of velocity vector of solarwind prior to interacting with Earth'a magnetic field.

So forward would be toward Earth and backward toward the sun. Up would be a vector generally parallel to the Earth's axis and pointing northward.

I ask because the electrons are supposed to turn anti clockwise and ions clockwise in any magnetic field where the flux is pointing up. But the electrons left of the Earth turning left to attempt to complete an anti clockwise loop would send them farther away from the magnetic field so they fail to complete such a loop because the field strength drops. The protons likewise on the right as they attempt to complete a clockwise loop.

But not the electrons on the right and positive ions on the left. Those should get trapped by Earth as they veer toward it.

We never see top down view of Earth deflecting solar wind in existing science illustrations, only side on views. Would a top down view show all the electrons left of Earth deflecting into the orbital path of the Earth and then flying away from Earth while ions into the previous Earth positions "behind" the Earth's orbital path and likewise away from Earth?

And would the electrons right of the Earth and ions left of the Earth have a higher tendency to fly toward Earth to get trapped by it more readily than their counterparts mentioned above at the same distances to Earth?

 

[berkeman]

Do solar wind electrons turn left and positively charged ions turn right if they are interacting weakly due to long distance with Earth's magnetic field

It looks like the situation is a bit more complicated than just trying to look at individual separated charged particles in the solar wind interacting with the Earth's magnetic field. The interaction of the Sun's and Earth's magnetic fields appears to be part of it all, and the Lamor orbits of the ions and electrons look to be small enough that they follow the magnetic field lines together:

(from a Google search on: simulation of the solar wind and Earth's magnetic field)

http://sci.esa.int/cluster/46262-solar-wind-enters-earth-s-magnetosphere/

 

[hutchphd]

Summary: For distant solar wind particles interacting weakly with Earth's magnetic field...

1. Electrons left of Earth fly left and away from Earth.

2. Electrons right of Earth veer left toward Earth

3. Ions right of Earth veer right and away from Earth.

4. Ions left of Earth veer right toward Earth.

True or false?

Do solar wind electrons turn left and positively charged ions turn right if they are interacting weakly due to long distance with Earth's magnetic field and fail to complete a loop for the electrons that are on the left of Earth and ions on the right? I assume electrons on the right and ions on the left will veer toward the Earth to be trapped in the magnetic field and spiral to the poles instead of deflecting away.

You first need to understand two things:

1. the magnetic field of the sun "connects" with the magnetic field of the earth. Some outer field lines start on Earth and terminate on the sun
2. the motion of charged particles emitted by the sun is to spiral about the field lines at constant total speed (unless acted upon by nonmagnetic forces)

Now you are in a position to do some independent research and thinking. For instance you will realize that opposite charges will have opposite helicity in their spiraling...

 

[darkdave3000]

http://sites.apam.columbia.edu/ctx/ctx_device.html
This site suggests that electrons and ions do drift into opposite sides of the Earth. Drift means to gyrate.

the picture from the site suggests that the electrons get trapped on the right which might mean that electrons on the left are deflected away as I suggested. Vice versa for ions.

 

[hutchphd]

It is difficult to respond to an illustration. My best guess is that the biggest asymmetry in the solar flux is because the positive ions have much more mass than free electrons (i.e.Beta particles). But I do not profess to know!

 

[Steelwolf]

I would think that the attraction of electron and ion would be more dependent on the North-South relationship of our magnetic field than the East to West rotation does. Thus the veering of + and - VS N and S.

The only other way I would think that the rotation would cause any such veering is that the morning side (East) magnetic field (both N and S) would be heading Towards the sun, so it's field is moving against the solar wind. The Evening side (West) would not have this 'buildup' since it is moving With the solar wind (again, both N and S), possibly bleeding off the possible buildup on dayside.

But I think that the North and South vectors mean a lot more than the East and West vectors do as far as charge differences with ions and electrons veering in our own Magnetic Field.

@hutchphd The mass differences may well go through the magnetic field differently E-W even with the 'buildup', but again I think the N-S polar pull would be several orders greater influence anyways.

I may be wrong, but this is where my past info/data stores leads me to believe.

 

[darkdave3000]

I am already making that assumption regarding the north south magnetic fluxes being the main thing influencing the particles. Electrons approaching the Earth on a horizontal plane including the Sun and Earth will roughly approach the equator. As they do they will encounter magnetic fluxes that are vertical (north-south). These fluxes would cause electrons to turn left to complete anti clockwise rotations.

Those electrons that are approaching Earth directly from the sun and those electrons left of it I would imagine should be easily deflected as they have a natural tendency to turn left (anti clockwise ) and this would point them away from Earth. As they move away from Earth thete is less of an incentive to keep turning left and gyrating back to Earth in loops since the magnetic influence on those particles drop very quickly to a negligible level as they speed away from Earth and her magnetic field.

The electrons going to the right of Earth should tend to get trapped in the field as they turn left toward a the magnetic field and exerience a stronger and stronger magnetic influence and subsequently gyrate.

Just imagine firing an automatic rifle with guided bullets programmed to veer left and only left when they approach a target. Those rounds on the left won't have much of a chance to hit it.

 

[Steelwolf]

Since a bullet, or any particle, is rotating while it moves, and the idea of 'taking a left turn' at a certain point does not line up with reality. Not all electrons are leaving the sun from a point source at the exact same angle, spin or direction compared to Earth, they start out random, not all the same. Each particle's idea of Left may be totally different than every other's

Your view seems to require that all the particles are spinning in the exact same plane and positioning of the electron's polarity with regard to planet Earth. This does not match reality in any way. You are almost stating that electrons are always being produced 'North side up and spinning to the right' ...and ONLY in that sort of framework would your idea of deflection make any sense.

But the electrons and ions are going to be generally randomly oriented overall as to spin and polarity, even with the solar and planetary magnetic fields affecting them, the forces of ejection from the sun, with the speed and turbulence of the accompanying solar wind, is going to have more effect at the individual particle level and thus make it more random.

Frankly, aside from possible buildup from the rotating geomagnetic field, I do not see any way that there would be a Left or Right distinction, either East or West.

North or South, yes, easily, but I do not see a reason for there to be a difference and considering that then the given GIF with charges moving against the Mag Field lines is just plain wrong.

Should take a look at the closer to Earth magnetic structure and things like the Van Allen Belts and the like but they work very specifically Within and are part of the geo-magnetic field.

 

[darkdave3000]

well I did some research on this left turn on the Internet and Wikipedia says that the turn is caused by altering the existing velocities in relation to the magnetic flux. No mention of particle spin or their poles.

 

[Steelwolf]

Actually, looking int it more, what I find is what is known as Ring Currents, but that is for slow moving ions, As per Wiki:"Earth's ring current is responsible for shielding the lower latitudes of the Earth from magnetospheric electric fields. It therefore has a large effect on the electrodynamics of geomagnetic storms. The ring current system consists of a band, at a distance of 3 to 8 RE,[1] which lies in the equatorial plane and circulates clockwise around the Earth (when viewed from the north). The particles of this region produce a magnetic field in opposition to the Earth's magnetic field and so an Earthly observer would observe a decrease in the magnetic field in this area.[2]:135 The negative deflection of the Earth's magnetic field due to the ring current is measured by the Dst index.

The ring current energy is mainly carried around by the ions, most of which are protons. However, one also sees alpha particles in the ring current, a type of ion that is plentiful in the solar wind. In addition, a certain percentage are O+ oxygen ions, similar to those in the ionosphere of Earth, though much more energetic. This mixture of ions suggests that ring current particles probably come from more than one source." (Wikipedia)So, my apologies, this IS right in there with Van Allen Belts etc, so, again there is the point to study. Ring Currents in particular.

 

[darkdave3000]

https://en.m.wikipedia.org/wiki/Guiding_center"If the magnetic field is uniform and all other forces are absent, then the Lorentz force will cause a particle to undergo a constant acceleration perpendicular to both the particle velocity and the magnetic field."https://en.m.wikipedia.org/wiki/Gyroradius

 

[darkdave3000]

http://ecampus.matc.edu/mihalj/scitech/unit3/electromagnets/electromagnetism.htmCheck out this animation and the article it came from.

 

[Steelwolf]

Yep, goes towards a pole, redirected by the charge of both poles, actually, both the repel and the attract, which is part of the reason for the reach there

 

[darkdave3000]

That's not what I'm saying regarding the poles comment.I'm reasserting that electrons veer away from Earth to the left and ions veer away to the right of Earth.

Electrons right of Earth and ions left of Earth both gyrate around the Earth making up the van Allan belt.

Backward being the sun for frame of reference. Poles both(north and south) take both electrons and ions

 

[hutchphd]

Perhaps this will be of help.

http://farside.ph.utexas.edu/teaching/plasma/Plasmahtml/node23.html

I believe this talks to the directionality of ring currents caused by curvature drift for various ions. As might be expected the two ionic charges go in opposite directions.

 

[darkdave3000]

Perhaps this will be of help.

http://farside.ph.utexas.edu/teaching/plasma/Plasmahtml/node23.html

I believe this talks to the directionality of ring currents caused by curvature drift for various ions. As might be expected the two ionic charges go in opposite directions.

This is not issue and I agree with ring currents.

I'm saying that there should be mostly only electrons entering the ring currents from the right of it and mostly only ions from the left of it.

Referencing the sun as "back" and Earth as "front". I need to draw a picture to make this topic clear.

In the attached picture:

Earth is the green circle.
Blue lines are electron path.
Red lines are ion path.

 

[hutchphd]

The ring currents drift round and round. These are particles that are also zipping from pole to pole along the field lines and reflecting from the polar field gradients at each end. I really don't think you understand the problem very well and suggest some elementary reading.
What prompts the initial question?

 

[darkdave3000]

please look at the edited post before your reply. I've added a picture.

 

[darkdave3000]

what prompted the question is my desire to simulate the solar wind in a planetarium software I'm programming. In real time.

I want to show a top down view of the Earth and solar wind. That is a view from the north pole.

 

[hutchphd]

That's an interesting project. I believe there are many good sources (with pictures) dealing with this subject. If I see a really good one I will let you know.

The left/right asymmetry is not at all as pronounced as you draw it. The spiral diameter is much smaller and the primary motion is helicity from pole to pole and back . The asymmetric drift is much much slower and as described previously. Not really of primary importance but you are not incorrect as to the physics, but I don't think you have the relative strengths correct in your head.

The other kicker here is that the magnitude of the solar wind varies hugely and the physics can get very complicated at higher fluxes. Sunspots are "magnetic storms" and related to such ejecta events.

That"s just about all I know...

 

[darkdave3000]

That's an interesting project. I believe there are many good sources (with pictures) dealing with this subject. If I see a really good one I will let you know.

The left/right asymmetry is not at all as pronounced as you draw it. The spiral diameter is much smaller and the primary motion is helicity from pole to pole and back . The asymmetric drift is much much slower and as described previously. Not really of primary importance but you are not incorrect as to the physics, but I don't think you have the relative strengths correct in your head.

The other kicker here is that the magnitude of the solar wind varies hugely and the physics can get very complicated at higher fluxes. Sunspots are "magnetic storms" and related to such ejecta events.

That"s just about all I know...

If you see any pictures illustrating the assymmetry that would be a first on the Internet! I have searched on bing and used view images only and could not find a single one!

 

[hutchphd]

I think that speaks to its relative magnitude...but I certainly will.

 

[darkdave3000]

I think that speaks to its relative magnitude...but I certainly will.

That picture was not drawn to scale but just to give a simple visual of the topic. But I do think that if all the distant electrons left of Earth veer left and away, that round be significant as there are a lot of them.

 

[darkdave3000]

typo: would be significant as there are lots of them.

 

[hutchphd]

You are entitled to your opinion, but I know of no hard science to support that notion (other than the drift velocity stuff). Good luck with the project.

 

[darkdave]

You are entitled to your opinion, but I know of no hard science to support that notion (other than the drift velocity stuff). Good luck with the project.

I’m looking for the evidence based on the formula for particle gyration which states that all electrons veer left to attempt to complete anti clockwise rotation. My hypothesis is that all the nearby electrons regardless of side (right or left) gyrate around the earth. But the distant ones would veer away and you your self admit this to be correct.Is it not self evident that there is more volume farther away from the Earth vs volume close to it?

Also are there any online simulations of magnetic fields and particles? Any applets?

<< Post edited by a Mentor >>

 

[castrogiovanni]

One thing to keep in mind is that although there are induced currents within the magnetosphere, as mentioned, quasi-neutrality outside of the magnetosphere will cause any separation of ions and electrons to be limited to the Debye length. That is about 10m in the solar wind.
Essentially, and as I understand it, anything that causes the ions and electrons to start to separate, will cause an ambipolar field to be set up, which will restore quasi-neutrality by accelerating one charge whilst retarding the other.
There is a poster and moderator at the Cosmoquest forum, who is a professional plasma astrophysicist. If you really want a definitive answer to your questions, I would suggest posting a question on their Q & A thread. I'm sure that if you bring the question to the attention of Tusenfem, he would be happy to give you an answer. You will need to sign up;

https://forum.cosmoquest.org/forumdisplay.php?8-Space-Astronomy-Questions-and-Answers

 

[berkeman]

Thread closed for Moderation...

 

[berkeman]

After some thread cleanup, the thread is re-opened.

Also are there any online simulations of magnetic fields and particles? Any applets?

Also, the OP is wanting to work on a simulation that will help him visualize the trajectories of the ions and electrons. There is a separate thread about resources to help him write his simulation here:

https://www.physicsforums.com/threa...ownloadable-vector-field.974899/#post-6208080

 

[darkdave3000]

Ok I’ve opened another thread on this topic and got more info about this topic here

https://forum.cosmoquest.org/showth...st-west-asymmetric-between-electrons-and-ions
However I can’t seem to see any of my new replies because I’m a newbie there and the moderator is either asleep on his job or has chosen not to make my new replies visible yet.

In any case what I realize now is that there is no magnetic field to interact with for the distant particles since the earth’s magnetic field is warped into a teardrop.

What I want to know next is the mechanism behind this. Is this directly caused by the sun’s magnetic field rotating slowly or is it caused by the solar wind ?

Lastly is the IMF a rotating helix because of the light speed propagation delay along each flux as the sun rotates?

 

[jasonRF]

What you need for your simulation depends on the fidelity you are aiming for. So far you have been thinking of the problem as isolated electrons and ions in magnetic fields, which of course gives you insight. You are correct that ions will deflect one way and electrons the other way. This forms a current, which of course creates a magnetic field and acts to confine the Earth's magnetic field. The current flows along a boundary called the magnetopause. If you want a self-consistent simulation that includes the effects of the fields on the particles as well as the fields generated by the particles, then you will need to do a fluid simulation (google magnetohydrodynamics). This is a giant task (way beyond your scope I suspect), so it seems more realistic to use models for the Earth's magnetic field and then simply compute the trajectories of individual solar wind particles as they encounter the Earth's magnetic field.

Just note that in reality things are a little more complicated. The solar wind flows at a speed that is faster than the Alfven speed, so a magnetohydrodynamic shock wave forms when the solar wind encounters the Earth. This shock wave is called the bow shock. The magnetopause discussed above is down-stream from the bow-shock. Furthermore, the sun also has a magnetic field (the so-called interplanetary magnetic field or IMF), and depending on the direction of that field as it encounters the magnetopause, there is a process called "reconnection" in which the solar and terrestrial magnetic field lines can become connected. When this happens the solar wind particles have direct access to the magnetosphere. The direction of the IMF also effects the details of the bow shock.

By the way, I would avoid thinking about ring-currents, since for the Earth's magnetosphere that term usually refers to a current system that is inside the magnetopause, not outside with the solar wind so it is probably not interesting for your simulation.

In short, the interaction of the solar wind with the Earth's magnetosphere is pretty complicated but quite fascinating. My graduate school specialization was in space plasma physics, and while I have forgotten a lot (I have been working outside the field for 20 years), one of the core classes was on solar-terrestrial physics which focused on just these topics.

If you have access to a university library, there are two books I can think of off-hand that may be helpful. The first is "the physics of space plasmas" by Parks. I have the first edition, which is fine, and there is also a second edition. Here is my review: https://www.physicsforums.com/threa...n-introduction-2nd-ed-by-george-parks.673612/
The second is "introduction to space physics" by Kivelson and Russel. Here is my review of the first edition: https://www.physicsforums.com/threa...ysics-by-m-g-kivelson-and-c-t-russell.673520/
Both of these are accessible if you have a good understanding of electromagnetic theory at the level of Griffiths (3rd or 4th year university course here in the USA). There are probably newer books, but I don't keep up with that field anymore.

Good luck,

Jason