Scientists solve centuries-old mystery of “bright nights”
Scientists have solved a centuries-old mystery of “bright nights” – an unusual brightness appears in the sky after dark and allows observers to see distant mountains, read a newspaper or check their clock.
Researchers suggest that when the waves in the upper atmosphere converge at specific places on Earth, which amplifies the natural light of the air, a weak light in the night sky that often appears in green due to the activities of the oxygen atoms in The upper atmosphere.
Normally, people do not notice the air of light, but nights of light can be visible to the naked eye, producing brightness without detailed explanation of historical observations.
Historical events and bright nights centuries ago. European journals and scientific literature also focused observations of these events in 1783, 1908 and 1916.
“Bright Nights exist, and are part of the variability of light wind that can be seen with satellite instruments,” said Gordon Shepherd, a hydrometer at York University in Toronto, Canada.
“The historical record is so consistent, dating back over centuries, the descriptions are very similar,” said Pastor, lead author of the study published in the journal Geophysical Research Letters.
Modern observations of bright nights on Earth are almost nonexistent light pollution. Even dedicated researchers have never seen a real bright night.
However, even before the advent of artificial lighting, bright nights were rare and very localized.
The researchers were able to see bright night events reflected in the wind data analysis Imaging Wind Interferometer (WINDII), an ancient instrument carrying NASA’s upper atmosphere research satellite (1991-2005).
They looked at mechanisms that increase the brightness of visible levels in specific places.
The air comes from the emission of light of different colors of light from chemical reactions in the upper regions of the atmosphere. The green part of the air of light occurs when sunlight divides molecular oxygen into individual oxygen atoms.
When atoms recombine, they eliminate the excess energy in the form of photons in the green part of the spectrum of visible light, giving the sky a greenish tint.
To find the factors that cause peaks in the air light and create bright nights, researchers observed for two years WINDII data from unusual air thrust profiles.
We identified 11 events in which WINDII detected an increase in air levels that would be visible to the human eye, which are described in detail in the study.
Finally, the researchers matched the event with the zoned waves, large waves in the upper atmosphere around the world and are affected by the weather.