Magnetosphere

I really don't get this concept. I understand magnetism and the poles, but not how there is a magnetic shield aound the outside of the atmosphere.

And the northern lights? Particles crashing together and making light?

please explain or discuss these things.

Originally posted by PocketKings
I really don't get this concept. I understand magnetism and the poles, but not how there is a magnetic shield aound the outside of the atmosphere.

And the northern lights? Particles crashing together and making light?

please explain or discuss these things.

I guess nobody is smart enough 😉

Originally posted by PocketKings
I guess nobody is smart enough 😉

Magnetic fields are like lines of spaghetti, they 'start' at one pole, say north, and line up till it hits a south pole. There is a north and south pole of the earth so all the lines go out from deep within the earth because there is an liquid iron core electric dynamo rotating around the earth in the center and that is like a power generator, so a magnetic field forms from way down in the earth.

So one pole of the field goes up and out from the north pole area and the other up and out from the south pole, antarctic region. The actual place that we call magnetic north and south wanders around some which means magnetic compasses are not accurate for long periods of time, the ones that try to be exact have to be updated every few years so you can tell your direction accurately.

But the field lines go way out into space and at some high altitude, maybe 600 miles up, over the equator, the lines are now going parallel to the ground and follow back down to the south pole. So when a solar flare sends its charged particles in the direction of earth, the magnetic field is our shield against what would be a lot of radiation hitting the ground but instead, follows the lines of magnetic force in a corkscrew fashion around the lines and ends up corkscrewing itself into the north and south pole, positive charges going one way and negative charges going the other.

So all that energy gets concentrated by the field lines and when they get to the poles, the particles slam into the upper atmosphere, say 40 miles up or so and they react with the neutral atoms of the upper atmospher and turns into a giant neon light bulb, of course with different ions, hydrogen, oxygen, nitrogen and the like, each one with its own distictive color, and they are very dynamic in the sense that it is happening in real time and will dissapate after a few hours as the charges mingle with and react to the atmosphere. They are very beautiful for sure, I saw plenty of them when I was in HS in Anchorage, Alaska.

Life on Earth BTW, is lucky to be underneath that magnetic shield. Places like the moon, and planets with no magnetic field like mars, are very unsafe, with raw radiation banging down from the sun in a solar flare, some of which are strong enough to knock out communications satellites, fry the electronics.

Even with the magnetic shield, some solar flares are so strong they can temporarily flatten the field lines all the way to the ground and cause power blackouts because in the US and Canada, and other large countries, power lines stretch for hundreds of miles and they are like a long antenna which converts the moving magnetic energy into a very large current pulse, directly from the interaction of the flattened magnetic field and those lines. Don't know if you know this but when a magnetic line moves by a conductor, an electric current is forced to flow in the conductor, thats how a generator works, and electric motors except in the opposite way.

So the magnetic field of the earth is very dynamic, it varies with the changing tides on the sun. Right now we are at the solar sunspot cycle at its minimum so there are very few solar flares blasting out but the sun has actually just started the new cycle and from now on for the next 6 years or so, solar flares will be on the rise.

Ham operators like that time in the cycle, with lots of sunspots because it makes the upper ionosphere, the top of the atmosphere, like a mirror for long wave radio waves, like from ten megahertz to about 200 mhz, the waves hit the underside of the ionosphere and its a lot easier for worldwide communications in those wave bands. Right now we hams are in the radio doldrums, like 30 megahertz, where there is a nice ham band, ten meters, and the 11 meter CB band, we are all just waiting for some new sunspots to start churning up so we can talk around the world on those bands again. A never ending cycle!