Does the angle of the magnetic field affect sunlight?

[Lord Challen]

With talk of the Earth's magnetic field slowly moving, (enough to cause navigational issues I've heard) does it effect how the sun's ray hit us? For example, the Northern Lights are solar partials interacts with the magnetic field (I think).

If the poles moves, would it affect the effectiveness of the magnetic field's protection against solar radiation.

 

[Christopher Grayce]

Magnetic fields only affect the motion of particles with an electric charge, or an electric or magnetic dipole (quadrupole, et cetera) moment. So, protons, yes, electrons, yes, even neutrons weakly (because while they have no electric charge they do have a magnetic dipole moment), but not photons (particles of light), which have no electric charge and no magnetic dipole moment.

That being said, the Sun emits much more than light: the solar wind consists of a constant stream of charged particles (mostly protons and electrons and ions). These particles *are* strongly affected by the Earth's magnetic field, so much so that they are generally deflected entirely from hitting the Earth, and those that are left tend to be bent towards the magnetic poles and come near the ground there. When they get near the ground these particles may ionize atoms high in the Earth's atmosphere, and when those ions recombine with electrons, light is emitted, which is where the aurora comes from.

So with the movement of the magnetic pole, the location where you can more easily see the aurora will change. The amount of radiation one gets from the impact of solar wind particles high above you will probably change a little, at very high latitudes (near the poles). However, it's worth bearing in mind natural normal variations, e.g. in the intensity of the solar wind, would probably be much greater than variations caused by a relatively slight (few hundred km) movement of the magnetic pole.

 

[Nik_2213]

Does it affect polarisation within the atmosphere ?

I'm reminded of the way optical calcite aka 'Iceland Spar' may *sometimes* be able to determine sun position through thick haze or over-cast. Apparently, this was known to Vikings etc...

Disclaimer: Sadly, the few examples I've handled were too 'fuzzy' to display useful birefringence...

 

[Lord Challen]

Magnetic fields only affect the motion of particles with an electric charge, or an electric or magnetic dipole (quadrupole, et cetera) moment. So, protons, yes, electrons, yes, even neutrons weakly (because while they have no electric charge they do have a magnetic dipole moment), but not photons (particles of light), which have no electric charge and no magnetic dipole moment.

Thanks Christopher.

I ask because I wonder if shifting magnetic poles could affect how energy hits the earth. Does the angle of magnetic flux push against incoming particles more at the poles, where the lines of flux might be coming up more directly than it might be going across at the equator?

 

[davenn]

Thanks Christopher.

I ask because I wonder if shifting magnetic poles could affect how energy hits the earth. Does the angle of magnetic flux push against incoming particles more at the poles, where the lines of flux might be coming up more directly than it might be going across at the equator?

Light, = electromagnetic radiation which ≠ particles

Particles are deflected by the Earth's magnetic field
Well to be more precise, a portion are deflected, others get trapped in the magnetic field and come down into the upper atmosphere, this is how we get auroraDave