Some spectacular images here
http://spaceweathergallery.com/indiv_up ... _id=109913
A similar solar event — known as the Carrington event – was recorded in 1859 by Englishman Richard Carrington. Observing the sun through a special telescope, Carrington saw a bright flash of light that lasted less than five minutes. That CME reached Earth the next day, creating a geomagnetic storm so powerful, auroras could be seen as far south as Jamaica and Hawaii.
According to a study published today in Nature Communications, solar storms could be much more powerful than previously assumed. Researchers at Lund University in Sweden have now confirmed that Earth was hit by two extreme solar storms more than 1000 years ago.
A few years ago researchers found traces of a rapid increase of radioactive carbon in tree rings from the periods AD 774/775 and AD 993/994. The cause for these increases was, however, debated.
"In this study we have aimed to work systematically to find the cause for these events. We have now found corresponding increases for exactly the same periods in ice cores. With these new results it is possible to rule out all other suggested explanations, and thereby confirm extreme solar storms as the cause of these mysterious radiocarbon increases", says Raimund Muscheler.
The study also provides the first reliable assessment of the particle fluxes connected to these events. Raimund Muscheler points out that this is very important for the future planning of reliable electronic systems:
"These solar storms by far exceeded any known events observed by instrumental measurements on Earth. The findings should lead to a reassessment of the risks associated with solar storms", says Raimund Muscheler.
... we provide evidence that these peaks were most likely produced by extreme solar events, based on several new annually resolved 10Be measurements from both Arctic and Antarctic ice cores. Using ice core 36Cl data in pair with 10Be, we further show that these solar events were characterized by a very hard energy spectrum with high fluxes of solar protons with energy above 100 MeV. The conclusion that one SPE (or a series of SPEs) is responsible for the production increase of 10Be, 14C and 36Cl at AD 774/5 (Fig. 2) is of particular significance because it implies that it must have reached an exceptional magnitude. In fact, no solar phenomena, including the Carrington event, have ever been unequivocally associated with a distinct increase in 10Be concentrations in ice cores. These results imply that the larger of the two events (AD 774/5) was at least five times stronger than any instrumentally recorded solar event.
Extreme space weather events, such as the Carrington event of 1859, are, by definition, rare. Because of this rarity, estimating their rates of occurrence, as well as the uncertainty associated with these estimates, is difficult. This is compounded by the fact that an event may be considered extreme with respect to one parameter, but not to another.
In this talk, I review our best statistical estimates for the probability of another Carrington event (or worse) occurring within the next decade. This depends crucially on an assumption concerning how the events are distributed in severity. In particular, we consider: power-law (with/without cut-off), log-normal, and (stretched) exponential distributions.
The results vary; however, we can be reasonably confident that the probability of another Carrington event occurring within the next 10 years is between 2-12%. This suggests that they are, at most, as likely to occur as other so-called “100-year” catastrophes.
Unlike most other disasters, however, the societal consequences of another Carrington-like event will not likely be regional; they will be suffered globally.
ROCKMAN wrote:Saw a great series about the universe recently. One focused on planet killing events. The most likely to hit the earth is what's being discussed. The correct term is CME...corona mass ejection. They have occurred more often then some understand from previous effects of CME's on the earth. The key is in which direction they shoot out. A major CME shoot from the sun when the earth is on the opposite has no effect on the planet. But if we are in the direct path of that narrow angle it would be much worse then isolated electrical problems. It could so disrupt the earth magnet field that a lethal dose of radiation could kill all plant and animal life.
The good news: it would develop so fast that by the time there was any hunt it was coming no one would have time to panic. The real nightmare would be a glancing blow by a major CME: millions dies within hours...hundreds of millions within year or so...and the survivors left to deal with the remains of a severely damaged planet.
The even better news: we could stop worrying about PO. LOL.
Alfred Tennyson wrote:We are not now that strength which in old days
Moved earth and heaven, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.
Tanada wrote:ROCKMAN wrote:Saw a great series about the universe recently. One focused on planet killing events. The most likely to hit the earth is what's being discussed. The correct term is CME...corona mass ejection. They have occurred more often then some understand from previous effects of CME's on the earth. The key is in which direction they shoot out. A major CME shoot from the sun when the earth is on the opposite has no effect on the planet. But if we are in the direct path of that narrow angle it would be much worse then isolated electrical problems. It could so disrupt the earth magnet field that a lethal dose of radiation could kill all plant and animal life.
The good news: it would develop so fast that by the time there was any hunt it was coming no one would have time to panic. The real nightmare would be a glancing blow by a major CME: millions dies within hours...hundreds of millions within year or so...and the survivors left to deal with the remains of a severely damaged planet.
The even better news: we could stop worrying about PO. LOL.
I read a story one time based on the survivors of a direct CME impact, they happened to be in South America and Antarctica when it hit on the 4th of July and irradiated everything living north of about 35 degrees south Latitude.
Seems those in the southern winter had the best luck because of the timing, they had the shortest daylight period and the CME only lasted a few days so their total dose was small. The people in summer and the tropics all died within a week from the radiation dose unless they were sheltered underground like Cheyenne Mountain Colorado. Oh and the people on Submarines were shielded by the water so they were just fine, but most of their families were not.
Alfred Tennyson wrote:We are not now that strength which in old days
Moved earth and heaven, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.
A solar storm that jammed radar and radio communications at the height of the Cold War could have led to a disastrous military conflict if not for the U.S. Air Force's budding efforts to monitor the sun's activity, a new study finds.
On May 23, 1967, the Air Force prepared aircraft for war, thinking the nation's surveillance radars in polar regions were being jammed by the Soviet Union. Just in time, military space weather forecasters conveyed information about the solar storm's potential to disrupt radar and radio communications. The planes remained on the ground and the U.S. avoided a potential nuclear weapon exchange with the Soviet Union, according to the new research.
Retired U.S. Air Force officers involved in forecasting and analyzing the storm collectively describe the event publicly for the first time in a new paper accepted for publication in Space Weather, a journal of the American Geophysical Union.
On May 18, 1967, an unusually large group of sunspots with intense magnetic fields appeared in one region of the sun. By May 23, observers and forecasters saw the sun was active and likely to produce a major flare. Observatories in New Mexico and Colorado saw a flare visible to the naked eye while a solar radio observatory in Massachusetts reported the sun was emitting unprecedented levels of radio waves.
A significant worldwide geomagnetic storm was forecast to occur within 36-48 hours, according to a bulletin from NORAD's Solar Forecast Center in Colorado Springs, Colorado on May 23.
Radar 'jamming'
As the solar flare event unfolded on May 23, radars at all three Ballistic Missile Early Warning System (BMEWS) sites in the far Northern Hemisphere were disrupted. These radars, designed to detect incoming Soviet missiles, appeared to be jammed. Any attack on these stations - including jamming their radar capabilities - was considered an act of war.
Retired Colonel Arnold L. Snyder, a solar forecaster at NORAD's Solar Forecast Center, was on duty that day. The tropospheric weather forecaster told him the NORAD Command Post had asked about any solar activity that might be occurring.
"I specifically recall responding with excitement, 'Yes, half the sun has blown away,' and then related the event details in a calmer, more quantitative way," Snyder said.
Along with the information from the Solar Forecast Center, NORAD learned the three BMEWS sites were in sunlight and could receive radio emissions coming from the sun. These facts suggested the radars were being 'jammed' by the sun, not the Soviet Union, Snyder said. As solar radio emissions waned, the 'jamming' also waned, further suggesting the sun was to blame, he said.
During most of the 1960s, the Air Force flew continuous alert aircraft laden with nuclear-weapons. But commanders, thinking the BMEWS radars were being jammed by the Russians and unaware of the solar storm underway, put additional forces in a "ready to launch" status, according to the study.
"This was a grave situation," Knipp said.
An international team of scientists has found evidence of a series of massive supernova explosions near our solar system, which showered the Earth with radioactive debris.
The scientists found radioactive iron-60 in sediment and crust samples taken from the Pacific, Atlantic and Indian Oceans.
The iron-60 was concentrated in a period between 3.2 and 1.7 million years ago, which is relatively recent in astronomical terms, said research leader Dr Anton Wallner from The Australian National University (ANU).
"We were very surprised that there was debris clearly spread across 1.5 million years," said Dr Wallner, a nuclear physicist in the ANU Research School of Physics and Engineering. "It suggests there were a series of supernovae, one after another.
"It's an interesting coincidence that they correspond with when the Earth cooled and moved from the Pliocene into the Pleistocene period."
Some theories suggest cosmic rays from the supernovae could have increased cloud cover.
The scientists believe the supernovae in this case were less than 300 light years away, close enough to be visible during the day and comparable to the brightness of the Moon.
Although Earth would have been exposed to an increased cosmic ray bombardment, the radiation would have been too weak to cause direct biological damage or trigger mass extinctions.
Return to Environment, Weather & Climate
Users browsing this forum: No registered users and 5 guests