2D Aurora Borealis: Solar Wind & Magnetic Field Lines

This is the cross-section companion to the 3D aurora simulator: instead of an orbitable night-sky scene, it draws Earth's curved magnetic field lines edge-on and streams charged solar-wind particles along them toward the polar upper atmosphere. Where the particles collide with oxygen and nitrogen, a flowing green-red-purple curtain of light builds up in real time. Drag the solar wind intensity, magnetic latitude and gas-mix sliders to see how a geomagnetic storm widens and brightens the auroral oval, and how the two dominant atmospheric gases each contribute their own color band to the display.