Guest post by Paul Dorian,
[note, Sorry Paul I missed the proper date by a couple days~cr]
The sun continues to be quiet with no visible sunspots during the last eleven days and it has been without sunspots 68% of the time this year which is slightly less than the 77% experienced during all of 2019. In fact, last year turned out to be the quietest year in terms of sunspots since 1913 with 281 spotless days as the solar minimum phase intensified from the year before. Back-to-back years of very high levels of spotlessness on the sun would certainly support the notion that this is indeed a noteworthy and deep solar minimum. Solar minimum represents the end of solar cycle #24 which featured the fewest number of sunspots since solar cycle 14 peaked in February 1906. Some of the predictions for solar cycle #25 suggest that it may peak in July 2025 and continue the trend of weakening solar cycles that began around 1980 when solar cycle 21 peaked in sunspot activity. Even weak solar cycles, however, can produce significant solar storms. In fact, it was this same time of year back in 1859 when a super solar storm – now known as the “Carrington Event” – took place during another weak solar cycle (#10). The event has been named for the British astronomer, Richard Carrington, as he observed from his own private observatory the largest solar flare which caused a major coronal mass ejection (CME) to travel directly toward Earth.
Recent studies have warned that these type of super solar storms may not be quite as rare as once thought (e.g., Hayakawa et al). Many previous studies of solar superstorms leaned heavily on Western Hemisphere accounts according to spaceweather.com, omitting data from the Eastern Hemisphere. This skewed perceptions of the “Carrington Event” of 1859, highlighting its importance while causing other superstorms to be overlooked. A super storm of the same magnitude as the “Carrington Event” in today’s world would very likely have a much more damaging impact than it did in the 19th century potentially causing widespread power outages along with disruptions to navigation, air travel, banking, and all forms of digital communication.
The solar storm of September 1, 1859
Coming just a few months before the solar maximum of 1860, numerous sunspots began to appear on the surface of the sun on 28 August 1859 and were being observed in different parts of the world. Just before noon on the cloudless morning of Thursday, September 1, 1859, 33-year-old astronomer Richard Carrington – widely acknowledged at the time to be England’s best – was in his own private observatory and, as he usually did on sunny days, he used his telescope to project an 11-inch wide image of the sun on a screen and carefully drew the sunspots that he saw. Suddenly, two brilliant beads of blinding white light appeared over the sunspots, intensified rapidly, and became kidney-shaped. He realized that he was witnessing something unprecedented and left for about one minute to find another witness. On returning within 60 seconds, he and his witness found that much had already subsided in that short time.
The next morning, Friday, September 2nd, 1859, when the CME arrived, it crashed into Earth’s magnetic field, causing the global bubble of magnetism that surrounds our planet to shake and quiver. The CME reached the Earth some 17.6 hours after the eruption which is much quicker than the normal journey time of 3 or 4 days as an earlier CME actually cleared the way of the ambient solar plasma for the second blast to move so quickly. Rapidly moving fields induced enormous electric currents that surged through telegraph lines and disrupted communications. In fact, telegraph systems all over Europe and North America went haywire and, in some cases, telegraph operators were literally shocked as sparks were flying and telegraph paper was often set on fire. Some systems actually continued to work despite being disconnected from their power supplies as aurora-induced electric currents still allowed messages to be transmitted. Skies all over Earth erupted in red, green and purple auroras – even in tropical locations like Cuba, Jamaica, El Salvador, the Bahamas and Hawaii. The auroras were so bright over the Rocky Mountains that their glow awoke gold miners who began preparing breakfast because they thought it was morning. People in the northeastern US could read a newspaper by the aurora’s light.
On Saturday, September 3, 1859, the Baltimore American and Commercial Advertiser reported, “Those who happened to be out late on Thursday night had an opportunity of witnessing another magnificent display of the auroral lights. The phenomenon was very similar to the display on Sunday night, though at times the light was, if possible, more brilliant, and the prismatic hues more varied and gorgeous. The light appeared to cover the whole firmament, apparently like a luminous cloud, through which the stars of the larger magnitude indistinctly shone. The light was greater than that of the moon at its full, but had an indescribable softness and delicacy that seemed to envelop everything upon which it rested. Between 12 and 1 o’clock, when the display was at its full brilliancy, the quiet streets of the city resting under this strange light, presented a beautiful as well as singular appearance.”
Today’s view of the “Carrington Event”
Back in the 19th century there were no X-ray satellites or radio telescopes and no one knew solar flares existed until that September morning. “What Carrington saw was a white-light solar flare—a magnetic explosion on the sun,” explains David Hathaway, solar physics team lead at NASA’s Marshall Space Flight Center in Huntsville, Alabama. “It’s rare that one can actually see the brightening of the solar surface,” says Hathaway. “It takes a lot of energy to heat up the surface of the sun!” The explosion witnessed by Carrington produced not only a surge of visible light, but also a mammoth cloud of charged particles and detached magnetic loops—a “CME”—and hurled that cloud directly toward Earth. Most experts today regard the “Carrington Event” of 1859 as one of the most powerful geomagnetic storms in recorded history. However, new findings suggest that it may be something that occurs more frequently than previously thought and perhaps more of an imminent threat to modern society.
Impact on today’s world
Today we know that solar flares happen frequently, especially during solar sunspot maximums. In today’s world, electronic technologies have become embedded into everyday life and are, of course, quite vulnerable to solar activity. Power lines, long-distance telephone cables, radar, cell phones, GPS, and satellites – all could be significantly affected by an event like this one. In other words, the world’s high-tech infrastructure could grind to a halt disrupting daily activities from purchasing a gallon gas to using the Internet.
Of particular concern is the fear about what this kind of solar storm could do to the electrical grid since power surges caused by solar particles can blow out giant transformers. If numerous transformers happened to be destroyed at once, it would likely take a painfully long time to replace them. The eastern US is especially vulnerable since the power infrastructure is highly interconnected so that failures in one location could cause failures in other regions. One long-term solution to this vulnerability would be to rebuild the aging power grid to be less susceptible to solar disruptions.
On the positive side, there is comfort in the fact that observations of the sun in today’s world are a constant with a fleet of spacecraft in position to monitor the sun and gather data on solar flares. Also, there is better forecasting today and solar scientists could give some sort of warning as to when solar flares might appear and whether a given storm is pointed at Earth. Improved forecasting can allow for mitigating actions to be taken since the most damaging emissions travel slowly enough to be detected by satellites well before the particles strike the Earth. For example, power companies could protect valuable transformers by taking them offline before a solar storm strikes. One thing is certain, we should be prepared for another massive solar storm of the magnitude of the “Carrington Event” of 1859 as new information suggests these have likely been occurring much more often than previously thought.
Meteorologist Paul Dorian