Study explains depletion in mesospheric ozone layer, its role in global climate change

Depletion of mesospheric ozone layer is caused by exact mechanism that creates aurorae, magnificent curtains of green light visible from Earth's polar regions. Because this depletion could have significance for global climate change, it is critical to comprehend it. Professor Yoshizumi Miyoshi of Nagoya University in Japan has headed a group of experts who have observed, analysed, and provided more understanding into this occurrence. findings were published in Nature's Scientific Reports publication.

Electron-plasma wave interactions allow trapped electrons to enter Earth's atmosphere

Electrons from sun are caught in magnetosphere, which is magnetic field region surrounding Earth. Electron-plasma wave interactions can allow trapped electrons to escape and enter Earth's upper atmosphere. Aurorae are caused by a phemen kwn as electron precipitation. However, current research suggests that this is also responsible for local ozone layer depletion in mesosphere (lower than rmosphere), which could affect our climate.

During a moderate geomagnetic storm over Scandinavian Peninsula in 2017, Prof. Miyoshi and his team used chance to change this ory. y were looking for "pulsating aurorae" (PsA), which are a sort of feeble aurora. Coordinated experiments with European Incoherent Scatter (EISCAT) radar (at an altitude between 60 and 120 km, where PsA occurs), Japanese craft Arase, and all-sky camera network allowed m to make ir observations.

trapped electrons in Earth's magnetosphere have a wide energy range, according to Arase data. Chorus waves, a form of electromagnetic plasma wave, were also detected in that region of . Computer simulations revealed that Arase had seen plasma waves causing se electrons to precipitate over a wide energy range, which is compatible with EISCAT findings in Earth's rmosphere.

Electrons with energies ranging from a few kilo electron volts to mega electron volts precipitate to induce PsA, according to EISCAT data. se electrons have eugh energy to enter our atmosphere to depths of less than 100 kilometres, up to a height of 60 kilometres, where mesospheric ozone is found. 

"PsAs occur almost daily"

Prof. Miyoshi describes, "PsAs occur almost daily, are spread over large areas, and last for hours. refore, ozone depletion from se events could be significant. This is only a case study. Furr statistical studies are needed to confirm how much ozone destruction occurs in middle atmosphere because of electron precipitation."

(Inputs from ANI)

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