- #31
jasonRF
Science Advisor
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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
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