GEOMAGNETIC STORMS ARE POSSIBLE THIS WEEK: Yesterday, a magnificent CME billowed away from the sun's eastern limb. A glancing blow from that CME combined with influences from an incoming solar wind stream could cause G1/G2 geomagnetic storms on Nov. 6th and 7th.
THE STRONGEST SOLAR FLARE OF THE SPACE AGE: Twenty-two
years ago today, the sun unleashed the strongest X-ray solar flare of
the Space Age. The underlying sunspot was not facing Earth; otherwise we
might have experienced a new Carrington Event. Instead, the debris flew
harmlessly off the sun's western limb:
The flare's extreme ultraviolet flash. Credit: SOHO
The explosion on Nov. 4, 2003,
was so intense that, at first, no one knew how strong it was. X-ray
detectors onboard GOES satellites were saturated for 11 minutes. This
clipped the readings at X17.4, but clearly it was stronger. Shortwave
radios in North America went silent as the continent experienced a deep
radio blackout--a hint at the flare's true severity.
Eventually, researchers figured it out. Our personal favorite estimate comes from this paper,
which describes how Earth's ionosphere was used as a giant solar flare
detector. Their answer, X45, has been confirmed by other studies.
This puts
it in the same ballpark as the Carrington Event. There were no X-ray
detectors in the 19th century, so researchers have to use indirect
methods to estimate the intensity of Carrington's flare on Sept. 1,
1859. Studies of auroras, ice cores, and magnetic disturbances suggest
values near X45, although some estimates go as high as X80.
Now for the
interesting part: The Nov. 4, 2003, flare occurred during the declining
phase of Solar Cycle 23. Twenty-two years later, we are near the same point
in Solar Cycle 25. As any good space weather forecaster will tell you,
the downslopes of solar cycles are prime time for big explosions. No one
knows why, but it's true.
In conclusion, don't be surprised if it happens again.
March 13, 2021: They call it “the day the sun
brought darkness.” On March 13, 1989, a powerful coronal mass ejection
(CME) hit Earth’s magnetic field. Ninety seconds later, the Hydro-Québec
power grid failed. During the 9 hour blackout that followed, millions
of Quebecois found themselves with no light or heat, wondering what was going on?
“It was the biggest geomagnetic storm of the Space Age,” says Dr.
David Boteler, head of the Space Weather Group at Natural Resources
Canada. “March 1989 has become the archetypal disturbance for
understanding how solar activity can cause blackouts.”
It seems hard to believe now, but in 1989 few people realized solar
storms could bring down power grids. The warning bells had been ringing
for more than a century, though. In Sept. 1859, a similar CME hit
Earth’s magnetic field–the infamous “Carrington Event“–sparking
a storm twice as strong as March 1989. Electrical currents surged
through Victorian-era telegraph wires, in some cases causing sparks and
setting telegraph offices on fire. These were the same kind of currents
that would bring down Hydro-Québec.
“The March 1989 blackout was a wake-up call for our industry,” says
Dr. Emanuel Bernabeu of PJM, a regional utility that coordinates the
flow of electricity in 13 US states. “Now we take geomagnetically
induced currents (GICs) very seriously.”
What are GICs? Freshman physics 101: When a magnetic field swings
back and forth, electricity flows through conductors in the area. It’s
called “magnetic induction.” Geomagnetic storms do this to Earth itself.
The rock and soil of our planet can conduct electricity. So when a CME
rattles Earth’s magnetic field, currents flow through the soil beneath
our feet.
Above: Grey areas indicate regions of igneous rock where power grids are most vulnerable to geomagnetic storms.
Québec is especially vulnerable. The province sits on an expanse of
Precambrian igneous rock that does a poor job conducting electricity.
When the March 13th CME arrived, storm currents found a more attractive
path in the high-voltage transmission lines of Hydro-Québec. Unusual
frequencies (harmonics) began to flow through the lines, transformers
overheated and circuit breakers tripped.
After darkness engulfed Quebec, bright auroras spread as far south as Florida, Texas, and Cuba. Reportedly,
some onlookers thought they were witnessing a nuclear exchange. Others
thought it had something to do with the space shuttle (STS-29), which
remarkably launched on the same day. The astronauts were okay, although
the shuttle did experience a mysterious problem with a fuel cell sensor
that threatened to cut the mission short. NASA has never officially
linked the sensor anomaly to the solar storm.
Much is still unknown about the March 1989 event. It occurred long
before modern satellites were monitoring the sun 24/7. To piece together
what happened, Boteler has sifted through old records of radio
emissions, magnetograms, and other 80s-era data sources. He recently
published a paper in the research journal Space Weather summarizing his findings — including a surprise:
“There were not one, but two CMEs,” he says.
The sunspot that hurled the CMEs toward Earth, region 5395, was one
of the most active sunspot groups ever observed. In the days around the
Quebec blackout it produced more than a dozen M- and X-class solar
flares. Two of the explosions (an X4.5 on March 10th and an M7.3 on
March 12th) targeted Earth with CMEs.
“The first CME cleared a path for the second CME, allowing it to
strike with unusual force,” says Boteler. “The lights in Québec went out
just minutes after it arrived.”
Above: Auroras over Pershore, England, during the March 13, 1989, geomagnetic storm. Credit: Geoffrey Morley.
Among space weather researchers, there has been a dawning awareness
in recent years that great geomagnetic storms such as the Carrington
Event of 1859 and The Great Railroad Storm of May 1921
are associated with double (or multiple) CMEs, one clearing the path
for another. Boteler’s detective work shows that this is the case for
March 1989 as well.
The March 1989 event kicked off a flurry of conferences and
engineering studies designed to fortify grids. Emanuel Bernabeu’s job at
PJM is largely a result of that “Québec epiphany.” He works to protect
power grids from space weather — and he has some good news.
“We have made lots of progress,” he says. “In fact, if the 1989 storm
happened again today, I believe Québec would not lose power. The modern
grid is designed to withstand an extreme 1-in-100 year geomagnetic
event. To put that in perspective, March 1989 was only a 1-in-40 or 50
year event–well within our design specs.”
Some of the improvements have come about by hardening equipment.
For instance, Bernabeu says, “Utilities have upgraded their protection
and control devices making them immune to type of harmonics that brought
down Hydro-Québec. Some utilities have also installed series capacitor
compensation, which blocks the flow of GICs.”
Other improvements involve operational awareness.
“We receive NOAA’s space weather forecast in our control room, so we
know when a storm is coming,” he says. “For severe storms, we declare
‘conservative operations.’ In a nutshell, this is a way for us to
posture the system to better handle the effects of geomagnetic activity.
For instance, operators can limit large power transfers across critical
corridors, cancel outages of critical equipment and so on.”
The next Québec-level storm is just a matter of time. In fact, we
could be overdue. But, if Bernabeu is correct, the sun won’t bring
darkness, only light.
👇👇👇👇TODAY:
CME IMPACT: A CME struck Earth today, July 25th, at 1422 UT. We're not sure, but this could be the halo CME launched toward Earth by a dark plasma eruption on July 21st. G1-class geomagnetic storms are possible in the hours ahead as Earth moves through the CME's magnetized wake. CME impact alerts:SMS Text
MAJOR FARSIDE SOLAR FLARE:
The biggest flare of Solar Cycle 25 just exploded from the farside of
the sun. X-ray detectors on Europe's Solar Orbiter (SolO) spacecraft
registered an X14 category blast:
Solar Orbiter was over the farside of the
sun when the explosion occured on July 23rd, in perfect position to
observe a flare otherwise invisible from Earth.
"From the estimated GOES class, it was the
largest flare so far," says Samuel Krucker of UC Berkeley. Krucker is
the principal investigator for STIX, an X-ray telescope on SolO which can detect solar flares and classify them on the same scale
as NOAA's GOES satellites. "Other large flares we've detected are from
May 20, 2024 (X12) and July 17, 2023 (X10). All of these have come from
the back side of the sun."
Meanwhile on the Earthside of the sun, the
largest flare so far registered X8.9 on May 14, 2024. SolO has detected
at least three larger farside explosions, which means our planet has
been dodging a lot of bullets.
The X14 farside flare was indeed a major
event. It hurled a massive CME into space, shown here in a coronagraph
movie from the Solar and Heliospheric Observatory (SOHO):
The CME sprayed energetic particles all
over the solar system. Earth itself was hit by 'hard' protons (E >
100 MeV) despite being on the opposite side of the sun.
"This is a big one--a 360 degree event,"
says George Ho of the Southwest Research Institute, principal
investigator for one of the energetic particle detectors onboard SolO. "It also caused a high dosage at Mars."
SolO was squarely in the crosshairs of the CME, and on July 24th it experienced a direct hit. In a matter of minutes, particle counts jumped almost a thousand-fold as the spacecraft was peppered by a hail storm energetic ions and electrons.
"This is something we call an
'Energetic Storm Particle' (ESP) event," explains Ho. "It's when
particles are locally accelerated in the CME's shock front [to energies
higher than a typical solar radiation storm]. An ESP event around Earth
in March 1989 caused the Great Quebec Blackout."
So that's what might have happened
if the CME hit Earth instead of SolO. Maybe next time. The source of
this blast will rotate around to face our planet a week to 10 days from
now, so stay tuned. Solar flare alerts:SMS Text
