The Northern Lights

Earlier this fall, I saw the Northern Lights in New England, USA. Normally, the Northern Lights are seen closer to the poles, and they rarely ever go farther away from the poles. I started wondering why they are visible in New England all of a sudden. What is causing this to happen? Most people just see the Northern Lights as a beautiful colorful phenomenon that occurs in the atmosphere and is visible in arctic regions of our planet. There is a lot more to them than just being colorful lights.

What exactly are the Northern Lights? Charged particles that are emitted from solar flares coming from the Sun enter our atmosphere. These charged particles collide with elements in the thermosphere and this releases energy as well as colorful lights that we see in the night sky. We normally observe the Northern Lights near the north pole. This is because our magnetic field acts like a funnel and carries the charged particles towards the poles where they accumulate. 

The Northern Lights became visible in New England due to a much larger solar flare. This solar flare emitted more charged particles. The increased amount of charged particles that led to more collisions and more light resulted in the Northern Lights being visible so far from the north pole. This large solar flare also emitted a lot of solar radiation which reacted with the ozone layer in the stratosphere. The ozone layer helps protect us from harmful solar radiation by breaking down the radiation. UV radiation from the Sun slowly weakens and damages the ozone layer over a long period of time. This natural process takes a long time, however humans have sped up the damaging of the ozone layer. Humans have made a chemical called chlorofluorocarbon(CFC) that is used as refrigerants, aerosol propellants, and solvents. CFCs release chlorine atoms in the stratosphere when broken down by UV radiation. The chlorine atoms then break down ozone into oxygen which weakens the ozone layer. This allows more radiation to reach Earth’s surface and this radiation is harmful to humans. 

The ozone layer is weakest over Antarctica. This is because strong wind currents carry CFCs towards Antarctica where the large amount of CFCs break down ozone. This has created what is known as the ozone hole. Radiation can easily reach the surface by going through the hole causing a lot of damage towards the planet. If we continue to produce CFCs and other harmful chemicals, the ozone layer will disappear and radiation will damage us and our planet. Many countries have realized this issue and have created the Montreal Protocol which helps protect the ozone layer by removing the usage of CFCs and other ozone-depleting chemicals. There are other ways to help protect our atmosphere and the ozone layer. We hope that the damage is recoverable and that the ozone layer continues to prevent harmful UV radiation from reaching the surface.

Source:Auroras - NASA Science