A recent geomagnetic storm caused an unusual blue glow to appear in the sky above a frozen landscape in Japan. Scientists Sota Nanjo of the Swedish Institute of Space Physics and Kazuo Shiokawa of Nagoya University have figured out the most likely explanation for the eerie phenomenon.
The team found that nitrogen molecular ions accelerated upward by some mechanism were responsible for the formation of the blue-dominant aurora. However, it remains unclear how these ions came to be at such high altitudes. The researchers’ findings suggest that an unidentified process in Earth’s atmosphere is involved.
Normally, Earth’s auroras appear as green and red hues due to the interaction between solar particles and atmospheric gases. But this blue-dominant aurora was different, appearing at low latitudes with a pink glow preceding it. The team used smartphone images from citizen scientists to measure the phenomenon in detail, finding that it had unique structures arranged along magnetic field lines.
The researchers believe that molecular nitrogen ions played a key role in the formation of the blue-dominant aurora, but they are still unsure what accelerated them upward. Further study is needed to understand this process and potentially unlock new insights into Earth’s atmosphere.
Source: https://www.sciencealert.com/mysterious-blue-aurora-hints-at-unknown-atmospheric-processes