High-speed solar winds from a "hole" in the sun's atmosphere are set to hit Earth's magnetic field on Wednesday (Aug 3.), triggering a minor G-1 geomagnetic storm.
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Forecasters at the National Oceanic and Atmospheric
Administration's Space Weather Prediction Center (SWPC) made the prediction
after observing that "gaseous material is flowing from a southern hole in
the sun's atmosphere," according
to spaceweather.com.
Coronal holes are areas in the sun's upper atmosphere where
our star's electrified gas (or plasma) is cooler and less dense. Such holes are
also where the sun's magnetic field lines,
instead of looping back in on themselves, beam outward into space. This enables
solar material to surge out in a torrent that travels at speeds up to 1.8
million miles per hour (2.9 million kilometers per hour), according to
the Exploratorium, a
science museum in San Francisco.
On planets with strong magnetic fields, like our own, this
barrage of solar debris is absorbed, triggering geomagnetic storms. During
these storms, Earth's
magnetic field gets compressed slightly by the waves of highly
energetic particles. These particles trickle down magnetic-field lines near the
poles and agitate molecules in the atmosphere, releasing energy in the form of
light to create colorful auroras, similar to the ones that make up the Northern Lights.
The storm produced by this debris will be weak. As a G1
geomagnetic storm, it has the potential to cause minor fluctuations in power
grids and impact some satellite functions — including those for mobile devices
and GPS systems. It will also bring the aurora as far
south as Michigan and Maine.
More extreme geomagnetic storms can disrupt our planet's
magnetic field powerfully enough to send satellites
tumbling to Earth, Live Science previously reported, and scientists have
warned that extreme geomagnetic storms could even cripple the
internet. Debris that erupts from the sun, or coronal mass
ejections (CMEs), usually takes around 15 to 18 hours to reach Earth,
according to the Space Weather
Prediction Center.
This storm comes as the sun ramps up into its most active
phase of its roughly 11 year-long solar cycle.
Astronomers have known since 1775 that solar activity rises
and falls in cycles, but recently, the sun has been more active than expected,
with nearly double the sunspot appearances predicted by NOAA.
Scientists anticipate that the sun's activity will steadily climb for the next
few years, reaching an overall maximum in 2025 before decreasing again. A paper
published July 20 in the journal Astronomy
and Astrophysics proposed a new model for the sun's activity by
separately counting sunspots in each hemisphere — a method the paper's
researchers argue could be used to make more accurate solar forecasts.
Scientists think the largest solar storm ever witnessed
during contemporary history was the 1859 Carrington Event, which released
roughly the same energy as 10 billion 1-megaton atomic bombs. After slamming
into Earth, the powerful stream of solar particles fried telegraph systems all
over the world and caused auroras brighter than the light of the full moon to appear as
far south as the Caribbean. If a similar event were to happen today, scientists
warn, it would cause trillions of dollars in damage and trigger widespread
blackouts, much like the 1989 solar storm that released a billion-ton plume of
gas and caused a blackout across the entire Canadian province of Quebec, NASA
reported.