Formation
The Sun
The Sun was born a gas. Its temperature is over 14 million degrees Celsius, causing pressure so enormous that hydrogen atoms would undergo nuclear fusion, resulting in helium. This nuclear reaction releases energy. While the sun has many parts, there is one that is very important to auroras; the corona. The corona surface is the hottest layer of Earth. Its gas molecules would lose particles, and move away from the Sun, making solar wind. Sometimes coronal mass ejection happens. This is when the core of the Sun radiates light, which you will be learning about in a paragraph later on. Then, the outer layer moves to the surface in convection cells. The electrical current of charged gas in the Sun creates a magnetic field. In some places, this magnetic field is so strong that it pushes through the surface. However, the electrically charged gas called plasma, stretches and breaks the magnetic field. Leading to billions of tons of plasma taken out of the sun. These solar storms can reach a speed of 8 million km/h. It would blow past mercury after 6 hours, and Venus after 12. In 18 hours it reaches Earth at 72 million km/h. ​​​
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Coronal Mass Enjections
What are coronal mass ejections? CMEs are protons and electrons that have been “shaken off” of hydrogen and helium atoms in the sun. CMEs are charged particles (often referred to as plasma) and travel in the form of solar wind.
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It is a release of plasma and magnetic fields from the sun's corona, which is the sun's outermost layer. The fastest CMEs can reach the Earth in 15-18 hours, meaning they travel at an approximate maximum speed of 10 million km/h. CMEs can reach a maximum size of ¼ of the distance between the Earth and the Sun, or approximately 3.75 x 10^7 km in length, and happens~2-3 times per day.
CMEs are generated from twisted magnetic fields, called flux ropes. They have too much tension and must be released by moving into a new configuration. This causes the sudden release of electromagnetic energy in the form of a solar flare. This results in the CMEs accelerating away from the sun very quickly, and these CMEs travel in the form of solar winds, often happening at the same time as solar flares.
Solar Flares
Solar flares are the largest explosive event in our solar system. It is an intense burst of radiation from electromagnetic radiation from the Sun. These can last anywhere from a few minutes to a few hours. They would be spotted when there are bright areas in the sun. Scientists can also monitor these flares using X-rays and optical light. These also commonly happen at the same time as CME's.​
Solar Cycle
The solar cycle is an 11-year cycle where the north and south poles of the sun flip sides and can be measured by the amount of sunspots on the corona of the sun. There are two main points during the solar cycle. There is the solar maximum and the solar minimum, where there is the most or least sunspots and solar activity respectively. Sunspots appear darker than the sun because they are cooler than the sun, and are large spaces with large amounts of magnetism. Additionally, they are cooler because their magnetic fields are able to block the heat from the sun. The solar cycle is a non-linear cycle and can vary each time. The timing of auroras is correlated to the solar cycle. Whenever there is a solar maximum there would be more solar storms.
Earth Atmosphere
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The Earth has a magnetic field. This field shields us from outer objects. However, plasma can distort our magnetic field. When they break it, the particles flow to the north or south pole, where there are weaker points. This distortion is determined by the size of the solar storm. These charged particles then interact with Earth's atmosphere, which does not have charged particles. There has also been an increasing issue with geomagnetic storms. These are a disturbance to the magnetic field on Earth. This causes heating of the ionosphere and the thermosphere. It also causes changes in the current. Furthermore, Currents on earth heading westward can produce magnetic disturbances.
Electromagnetic Radiation
Electromagnetic radiation produces photons. When an atom receives energy, the electrons have excess energy causing them to jump to another shell. The electron is then in an excited state (unstable,) which leads to it jumping back to its previous shell. The lights from these auroras do the exact same thing. In the ionosphere, there are many different particles including hydrogen, nitrogen, helium, and oxygen. With the high speed of the plasma, the collision results in the particles absorbing the energy and releasing photons in beautiful shapes and colours.
Auroral Ovals
Aurora ovals is a scientifically proven area that has the highest possibility to view auroras. This area can change shape and size, but will always be there. It is 300 km above the Earth's surface and rotates with the Earth's magnetic field. There is also an auroral zone which is a piece of land that surrounds the auroral ovals.
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