On May 5, the solar wind flow reached Earth, triggering geomagnetic
storms of class G1 and G2. High in the atmosphere, hot plasma jets began
to flow through the magnetic field of our planet, and suddenly “Steve”
appeared. Alan Dyer photographed a glowing purple arc over Gleichen in
the Canadian province of Alberta.
“Steve” appeared in a completely new form on Sunday evening, having
arranged a magnificent light show in the south of Alberta. At first, the
arc was weak, then it became brighter, stretching across the sky, “says
Dyer.
The phenomenon was discovered by sky monitors in Alberta just a few
years ago, although, undoubtedly, was active long before that. Narrow
tape is associated with aurorae, but has a certain shape, color and
habitat. At the moment, scientists consider “Steve” a manifestation of
hot plasma currents in the upper atmosphere.
In a recent article, Elizabeth MacDonald of NASA’s Goddard Space
Flight Center “Steve” is associated with a phenomenon called “subauroral
ion drifts” (SAID). Satellites recorded thousands of SAID: most often
they appear in the spring and autumn and seem to prefer latitudes of
about + 60 °. But this weekend, “Steve” appeared south of the usual.
Greg Ash saw the tape over the city of Ili in the US state of Minnesota
at latitude of + 47.9 °.
“As you can imagine, I was absolutely shocked. This was my first meeting
with Steve, and I could see it with the naked eye, including the
ripples of green and purple, “says Ash.
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Space