What causes geomagnetic storms, and why are they currently visible in the U.S, while locations like Iceland often experience them more frequently?
In: Planetary Science
Not a scientist, but I’ll give it a go. The sun gives off charged particles (geomagnetic storms) from time to time and those particles, because they have a charge are stopped by the Earth’s magnetic field which is strongest at the poles (north pole, south pole). These particles are what cause the Auroras.
As with most beauty in the world, it all starts with the sun. The sun is a huge ball of plasma, it is very hot, and has many magnetic fields. Sometimes these magnetic fields become kinked or knotted up and since plasma likes to follow magnetic fields some of the plasma on the surface of the sun follow the kinks and knots.
Well sometimes these kinks become so tight that they kind of just snap think about a rope with a knot in it, if you pull really hard with a lot of force the rope will actually shoot out, with the magnetic fields a similar thing happens and flings some of that hot plasma away from the sun this is called a coronal mass ejection or a CME.
Now this plasma has both an electric charge and a lot of speed, normally the earth has a magnetic field around it that can deflect the solar winds and most of the smaller CMEs, but when the CME is large enough it can actually bend the magnetic field of the earth enough that the plasma of the CME can interact with the upper layers of the atmosphere.
The way it interacts with the upper atmosphere is it discharges some of that electrical charge it has and causes some of the atoms in the atmosphere to produce light.
The bigger the CME the closer to earth the plasma can get, and the closer it can get the more colors you get to see and the brighter they will appear.
The reason places very north or very south see more lights is because the magnetic field of the earth isn’t in the same orientation as it is say closer to the equator, basically closer to the poles the more perpendicular the magnetic field of the earth is to the earth/solar wind, which makes it so a smaller CME is needed to cause the northern or southern lights, to the point where you could see the northern or southern lights with just the standard solar wind.
Solar winds contain charged particles; when they hit the earths atmosphere the particles create lights
Normally these solar winds “contact” at the upper part of the northern hemisphere; like Canada;Sweden;Russia:Alaska….northern most lands
This is an exceptionally powerful breeze so the lights will be seen further south than usual
The gravitational influence of Venus, Jupiter and the Earth may be enough to alter the internal structure of the Sun and this may result in the change in sun spot activity and solar flares which we see in periods of solar minimum and solar maximum. https://youtu.be/gLzmO-phS60
The charged particles released by the Sun strike the Earth, which is protected by the magnetosphere as the particles strike the magnetosphere it pushes the magnetosphere closer down towards the surface of the Earth the particles in the wind can strike oxygen and nitrogen in the atmosphere causing them to glow. https://youtu.be/CPzrDBFzy8A minor impacts on the magnetosphere only bend it a bit so only northern areas experience the observable change.
The sun’s corona…. the brightest and outermost part of the sun..(think flames of a fire) periodically escapes the sun… like sometimes you see flames in a camp fire separate from the main fire and follow the smoke and dissipate…
Well the sun is doing that on a large scale and this coronal mass ejection is filled with charged particles.
That mass of Corona makes its way to earth and collides with our earth’s magnetic field… and we see those particles interacting with the magnetic field and our atmosphere
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