On January 6, 2020,
SpaceWeather.com
reported something
unexpected in the soil
of northern Norway.
"Electrical currents
started flowing,"
reported
Rob Stammes,
who monitors
ground currents
at the Polar
light center
geophysical
observatory
in Lofoten.
A sudden surge
around 1930 UT:
"It seemed to be
some kind
of shockwave,"
says Stammes.
"My instruments detected
a sudden, strong variation
in both ground currents ,
and our local magnetic field.
It really was a surprise."
NASA's ACE spacecraft
also detected something.
About 15 minutes
before the disturbance
in Norway, the
interplanetary magnetic
field (IMF) near Earth,
abruptly swung around
180 degrees, and the
solar wind density
jumped more than
five-fold !
Earth may have crossed
through a fold in the
heliospheric current sheet
- a giant, wavy membrane
of electrical current
rippling through
the solar system.
Crossings can cause
these kinds of effects.
While currents flowed
through the ground,
auroras filled the sky.
An aside:
I've never seen an aurora, which we call "Northern Lights", here in Michigan, USA, but always wanted to see them. My wife said she saw them as a child, in the 1950s, at the family's country cottage a few hours north of Detroit. Her parents didn't know what the lights were at a time. I've seen many rainbows, including a stunning double rainbow.
The outburst of lights
was photographed
from Utsjoki, Finland
"What a surprise!", said
the lucky photographer
Rayann Elzein.
"The auroras were sudden
and dynamic, with fast-moving
green needles and several
purple fringes!"
The Finland aurora
and the Norway
ground currents
were caused
by the same thing:
Rapidly changing
magnetic fields.
For auroras, magnetic
vibrations shake loose
energetic particles,
which rain down on
the upper atmosphere,
creating aurora lights
where they strike.
Just below Earth's surface,
magnetic vibrations caused
currents to flow in Norway,
triggering Rob Stammes'
ground sensors.
"We couldn't see the
auroras in northern Norway
because of cloud cover,"
said Stammes,
"We had to be satisfied
with the electricity underfoot."