May 13, 2021
Scientists call it a “diffuse auroral eraser.” That’s because this newly named aurora first appears as a bright stripe over a diffuse auroral background. Then, when it disappears, it scrubs out the faint auroral light behind it.
Scientists at the University of Iowa said on May 6, 2021, that they’ve given the name
diffuse auroral eraser to a new type of aurora not often seen and not well understood. This new and elusive type of aurora – noticed in a 19-year-old video made by a physicist – has never before been described in scientific literature. The new name
diffuse auroral eraser describes how this sort of aurora first appears as a brighter stripe within a fainter, more diffuse aurora. When the stripe disappears, it blots out the diffuse light from the background aurora, as though the aurora is erased from that specific patch of sky. Then, after about 20 seconds, the diffuse background aurora reappears.
10 MAY 2021
Not all auroras slither through the sky like snakes. Some – called diffuse aurora – are more like an even glow dispersed throughout the sky.
Scientists know a fair bit about these diffuse auroras, but an old video from 2002 revealing what seems to be an undocumented auroral phenomenon shows we definitely don t know everything.
They appear as a section of diffuse aurora that rapidly brightens, then disappears and also erases the background aurora. Then, over the course of several tens of seconds, the diffuse aurora recovers to its original brightness.
The team, made up scientists from the University of Iowa, University of Calgary, and NASA, has dubbed the phenomenon diffuse auroral erasers .
The researchers say the behavior, which they call diffuse auroral erasers,
has never been mentioned in the
scientific literature. The findings appear in the
Journal of Geophysical Research Space Physics.
Auroras occur when charged particles flowing from the sun called the solar wind interact with Earth s protective magnetic bubble. Some of those particles escape and fall toward our planet, and the energy released during their collisions with gases in Earth s atmosphere generate the light associated with auroras. The biggest thing about these erasers that we didn t know before but know now is that they exist, says Allison Jaynes, assistant professor in the Department of Physics and Astronomy at Iowa and study co-author. It raises the question: Are these a common phenomenon that has been overlooked, or are they rare?
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VIDEO: The famed northern and southern lights have been studied for millennia, but they still hold secrets. In a new study, physicists led by the University of Iowa describe a new. view more
Credit: Riley Troyer, University of Iowa
For millennia, humans in the high latitudes have been enthralled by auroras the northern and southern lights. Yet even after all that time, it appears the ethereal, dancing ribbons of light above Earth still hold some secrets.
In a new study, physicists led by the University of Iowa report a new feature to Earth s atmospheric light show. Examining video taken nearly two decades ago, the researchers describe multiple instances where a section of the diffuse aurora the faint, background-like glow accompanying the more vivid light commonly associated with auroras goes dark, as if scrubbed by a giant blotter. Then, after a short period of time, the blacked-out section suddenly reappears.