A recent study claims that Aurora’s beautiful and magical phenomenon, which is also called Northern Light, might be in charge of depleting the ozone layer, the protective shell.
In a recent development study, it has been shown that the phenomenon which seeds aurorae (a.k.a. northern lights and polar lights)the magical curtain of green lights visible from the polar region of the Earth- is responsible for the depletion of Mesospheric Ozone Layer.
This phenomenon might play a significant role in global climate change relating to the depletion of the protective shell of the Earth.
Said a group of scientists led by Professor Yoshizumi Miyoshi from Nagoya University, Japan, which is why studying the phenomenon is essential. The findings have been published in Nature’s Scientific Reports.
Explanation of depletion in mesospheric ozone layer
In the magnetosphere- the magnetic field region around the Earth- the electrons (the negatively charged particle) from the sun remain imprisoned.
When the Electrons and plasma waves interact, it can cause the trapped electrons to escape and enter the Earth’s upper atmospheric layer (thermosphere).
This incident of Electron precipitation is responsible for the occurrence of Aurora Lights, which is also a reason for depleting the ozone layer in the mesosphere and may have some impression on the global climate.
To add to it, the significant depletion of the ozone layer takes place during the aurorae. Even after studying the electron precipitation concerning Aurorae, scientists have not annotated the causes of mesospheric ozone depletion.
During a moderate geomagnetic Scandinavian Peninsula storm in 2017, Professor Miyoshi and his team changed the narrative regarding this matter.
The team carefully studied the observations at “Pulsating Aurorae” (PsA), a faint aurora, through synchronized experiments with EISCAT, European Incoherent Scatter radar, the Japanese Spacecraft Arase and all-sky camera network, at an altitude of 60-120 Km where it occurs.
The study of Arase data showed that the trapped electrons in the Earth’s magnetosphere has a wide range of energy and indicated the presence of chorus waves, an electromagnetic plasma wave type, in that space region.
Simulations of the computer showed that the Japanese Spacecraft Arase had detected plasma waves causing precipitations of these electrons across the wide energy range, which appeared consistent with EISCAT observations in Earth’s thermosphere.
EISCAT observations analysis showed that the electrons from a few keV (kilo electron volts) to MeV (mega electron volts) precipitate to cause PsA.
These electrons carry sufficient energy to penetrate the atmosphere to lower than 100 Km up to a~ 60km altitude, where the mesospheric ozone layer occurs.
The EISCAT computer simulations showed these electrons deplete the mesospheric ozone by more than 10% immediately upon hitting it. Prof. Miyoshi explained that PsA occurs almost daily, is spread over large areas and last for hours.
Thus, from such incidents, ozone depletion is significant. Speaking of more major importance, Prof. Miyoshi said that this is only a case study.
Further statistical analyses are required to confirm how much ozone depletion occurs in the middle atmosphere because of electron precipitation. After all, the impact of this phenomenon on the climate could potentially impact modern life.