Which phenomenon is a direct result of solar wind interacting with the Earth's atmosphere?

The Aurora Australis, also known as the Southern Lights, is a phenomenon that occurs when charged particles from the solar wind collide with gases in the Earth's atmosphere. This interaction primarily takes place near the polar regions, where the Earth's magnetic field lines converge. The energy from these collisions excites the gaseous particles, leading to the stunning displays of light characteristic of auroras.

Solar wind consists of a stream of charged particles, primarily electrons and protons, emitted by the sun. As these particles travel through space, they can reach Earth and are directed by its magnetic field towards the poles. When they enter the atmosphere, they interact with oxygen and nitrogen molecules, producing the brilliant colors seen in auroras.

In contrast, solar flares, coronal mass ejections, and sunspots relate to different aspects of solar activity, such as eruptions on the sun's surface or areas of magnetic activity, and do not directly contribute to the auroras seen in Earth's atmosphere. Thus, the direct result of solar wind interacting with the Earth's atmosphere manifests as the beautiful phenomenon of the Aurora Australis.