The Aurora and the Solar Wind For the most part, Earth’s dynamo system is invisible, but there is a part of it we can see, which is called the aurora, or the Northern Lights. This is where the fuel particles come together in large concentrations as they go though the system. The large concentration of charged particles builds up at the North and South Poles to form the aurora. At the North Pole they are called aurora borealis. At the South Pole they are called aurora australis. The charged particles come from space as part of the solar wind. During sun spot activity, the amount of charged particles increases, so the aurora expands and becomes this fantastic brightly colored display of lights.  The charged particles are constantly traveling back and forth up and down the magnetic field’s lines of force lighting up the sky at the poles. These energy particles are trapped in the Earth's magnetic field. As they spiral back and forth along the magnetic field lines, they come down into the atmosphere near the poles where the magnetic field lines disappear into the Earth. Energetic electrons collide with oxygen and nitrogen molecules in the atmosphere. This excites the molecules, and when they decay from the excited state, they emit the light we see in the aurora.  Our Solar System, Chapter 2 Magnetosphere, Chapter 3 Radiation Belts, Chapter 4 Magnetic Fields, Chapter 5 Earth’s Dynamo, Chapter 6 Dynamo Systems, Chapter 7 The Sun as a Dynamo, Chapter 8 Auroras Chapter 9 Space Weather Chapter 10 References |