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The Northern Lights Explained
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The Northern Lights Explained

Mar 174 min read

The Northern Lights, scientifically known as aurora borealis, are one of nature’s most intriguing phenomena, creating a vibrant display filled with different colors and movements into the sky. This almost supernatural dance of the sky, visible in high-latitude areas, captivates countless individuals from around the world.



Of course, these beautiful displays of light don’t magically appear. At the heart of the Northern Lights lies a complex chemical reaction. The collisions between nitrogen and oxygen atoms cause them to become excited and emit photons as they return to their ground state, generating visible light. Joe Hernandez from NPR also adds that when the “magnetic field snaps back, the force of that recoil creates powerful ripples known as Alfvén waves about 80,000 miles from the ground. As those waves approach  Earth, they move even faster thanks to the planet's magnetic pull” (Hernandez, 2021). Electrons hitch a ride onto these waves to breach into Earth’s atmosphere, reacting with the nitrogen and oxygen atoms.  The Northern Lights’ mesmerizing colors are a direct result of these interactions between atoms. When these atoms collide and produce visible light, they are presented in an array of colors. Oxygen produces green and red light, while nitrogen produces blue, purple, and pink colors. Furthermore, “green-colored auroras are most frequent, resulting from interactions with oxygen molecules at lower altitudes (between 100-300 km or 62-180 mi), while the less commonly occurring red auroras form from interactions with higher altitude (above 300 km or 180 mi) oxygen molecules” (Center for Science Education, n.d.). The color variation brings tourists and scientists to awe, with each color and movement providing more insight into the chemical process. 


Along with the different prominent colors, the shape and dance of the lights also fall under an algorithm. These dynamic shapes and movements of the Northern Lights are derived from the Lorentz Force. The Lorentz Force is represented by the equation F=q(E+vB), where the different variables stand for different factors that play a role in the Northern Lights. ”-‘F’ represents the force acting on the charged particles, ‘q’ is the charge, ‘E’ is the electric field, ‘v’ is the velocity of the interacting particles, and ‘B’ is the magnetic field” (da Vinci, 2024). This force causes the charged particles to follow along the Earth’s magnetic field lines, creating the different patterns of the aurora. Therefore, “the interplay between the particles and the magnetic field lines gives rise to the captivating shapes and fluid motions observed in the night sky.” (da Vinci, 2024). 


Not only does the magnetic field explain the different patterns, but also the prominence of visible displays towards the poles. The magnetic field guides charged solar particles toward the polar regions, where they collide with atmospheric gasses to produce light. Additionally, the prominence towards the poles and Antarctica, Alaska, Greenland, Norway, and the Arctic Circle is partially related to the ideal gas conditions near high altitudes. In a research paper, Christina Shaw states that “the concentration of these particles at the poles, coupled with the high latitude locations, creates optimal conditions for aurora displays.” The particles follow the magnetic field lines towards the polar regions because they are charged. Since the atmospheric conditions at the poles are significantly colder, a perfect environment is created for the lights to be displayed. 


Usually, these lights will only be visible at polar regions. However, on May 8, 2024, an extraordinary solar event caused the aurora borealis to be visible to the entire Midwest of the United States of America. “Such solar events, including solar flares and coronal mass ejections, can expand the reach of the Northern Lights. These events amplify the flow of charged particles into the Earth’s atmosphere, allowing the auroras to be seen in unexpected locations” (Dunn, 2024). Since they typically are confined towards the poles, this occurrence was due to an extreme solar event that significantly raised the number and intensity of the charged particles intruding Earth’s atmosphere. 


As many people know, the auroras are a beautiful and rare sight to see; though, this phenomenon comes with significant risks. The most extreme recorded solar storm, the Carrington Event of 1859, forced auroras into Central America and Hawaii. However, the tropical areas were not the only ones impacted. A more recent geomagnetic storm in 2003 disrupted power grids in Sweden, damaging transformers in South Africa (Dunn, 2024).

This event severely disrupted telegraph systems for airplanes, NASA satellites, and other revolutionary instruments that have taken decades for humans to perfect. Similarly, the solar activity from May 8, 2024 has produced multiple coronal mass ejections, each releasing billions of tons of plasma from the sun’s outer atmosphere.


Aside from its negative effects, the Northern Lights are a magnificent display of nature’s beauty and scientific complexity. From the specific chemical reactions to the influence of the Earth’s magnetic field, the auroras display a very important understanding between the forces of our universe and Earth’s atmosphere, allowing us to observe the impacts of solar activity on Earth. Further studies of this phenomenon can contribute to advancements in space weather prediction, shielding mechanisms for satellites, and possibly a generator that uses emitted plasma to convert to energy. Still, all science aside, the Northern Lights are a once-in-a-lifetime opportunity to experience a natural and breathtaking phenomenon.


 

Written by: Rajiv Chandramouli


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