Insurer Lloyd’s of London says Earth is due for a major solar storm
Solar Storm on August 1, 2010 as seen by STEREO [HD Video] (Photo credit: NASA Goddard Photo and Video)
Rosanne Skirble / VOA
With the sun nearing the peak of its 11-year cycle, scientists say a powerful solar storm may be headed our way, which could shut down electricity supply networks and disorient GPS and satellite systems.
The worst known geomagnetic solar storm hit Earth in 1859, observed and sketched by astronomer Richard Carrington. The Carrington event upset global telegraph communications. Surprised operators watched sparks fly from telegraph lines and set telegraph paper on fire.
While not nearly as powerful, other storms in history have cut power, knocked out telephone service, short-circuited satellites and caused radio blackouts.
Major solar storm overdue
The Earth is overdue for another Carrington-like storm, according to a new report released by Lloyd’s of London, the world oldest insurance market.
Co-author Neil Smith says it could be even more devastating, given the worldwide dependence on electric power supply grids.
“We are estimating that 20-40 million people might be without power from anywhere up to one, even two years,” he said. “That has to do with the critical issue of replacement transformers. That number of people without power could result in an economic cost somewhere between $0.6 trillion to $2.6 trillion.”
The focus of the report is North America. Smith says the continent’s geologic features and aging infrastructure put it at high risk for bad solar weather. The power grid, satellites, aircraft communications, astronauts and oil pipelines are particularly vulnerable. “If there was a big solar flare, it could of course knock out a whole lot of transformers.”
Improved computer models
Michael Wiltberger, a scientist at the High Altitude Observatory of the National Center for Atmospheric Research in Boulder, Colorado, builds models to track the sun cycle, ultimately to better predict solar weather.
He observes coronal mass ejections (CMEs) that race through the solar system at speeds of three million to five million kilometers per hour. They reach Earth in less than two days. Wiltberger sees them, at the speed of light, less than eight minutes after an eruption on the sun.
That gives space weather forecasters some lead time, but Wiltberger says predicting precisely when and where a storm will hit is much more complex.
“The real challenge that we have, that we are struggling with and trying to build into our numerical models, is to understand what the magnetic field is going to be inside this hot gas that is coming out,” he said, “because it’s that magnetic field that is the key that unlocks the entry of energy and mass into the Earth’s, near-Earth’s region.”
Wiltberger says the models could provide a framework to monitor a storm and improve predictions. He hopes that system will be operational within five years.
Greater international cooperation needed
In the meantime, Neil Smith of Lloyd’s of London is calling for greater cooperation to mitigate the impact before the next big storm comes on the horizon.
“We are just raising awareness of the issue, because step one is to get different parties aware that this is a potential issue,” he said. “And then we need to work with governments and the utility industry to tackle it. It’s not something that any one party could actually solve on their own.”
Smith adds that such work is critically important, to avoid what could become large-scale economic and societal chaos.
Science Class: NASA gathers more solar flare evidence
Two satellites watching the sun get more evidence on why solar flares occur
July 15, 2013, 11:52 AM — NASA’s YouTube channel always provides highly visual content of different objects in space, but I’m a huge fan of their solar flare footage and animations.
The NASAexplorer channel has another one up today – this time with “the most comprehensive movie ever of a mysterious process at the heart of all explosions on the sun: magnetic reconnection. Get a quick primer on what this means and watch some very cool solar explosions while you’re at it.
Keith Shaw rounds up the best in geek video in his ITworld.tv blog. Follow Keith on Twitter at@shawkeith. For the latest IT news, analysis and how-tos, follow ITworld on Twitter,Facebook, and Google+.
Solar Dynamic Loops Reveal a Simultaneous Explosion and Implosion, Plus Evidence for Magnetic Reconnection
July 2, 2013 — Movies of giant loops projecting from the surface of the Sun are giving new insights into the complex mechanisms that drive solar flares and Coronal Mass Ejections (CMEs). These eruptions release vast energy and electrically charged particles that can affect Earth through space weather. Imagery from NASA’s Solar Dynamics Observatory (SDO), used in two separate studies, shows the dynamics of loops before, during and after eruptions. Results will be presented at the National Astronomy Meeting in St Andrews.
Coronal loops are giant magnetic arches filled with hot plasma at temperatures of over a million degrees Celsius. The structures are anchored in the dense photosphere, the visible surface of the Sun. The loops form the building blocks of the corona, the halo surrounding the Sun that can be seen during a total eclipse. They are dynamic structures that oscillate back and forth after explosive events such as solar flares.
Researchers from the University of Glasgow observed four groups of loops that contracted rapidly during a flare on 9 March 2012. The loops had a ‘staggered start’ to their collapse, showing delays of 60-80 seconds from the inner to the outer loops.
“This event is a great example of a simultaneous implosion and explosion," said Dr Paulo Simões. “Our interpretation is that energy is transferred from the magnetic field to power the flare, leaving a pocket of reduced magnetic support that causes an implosion. The staggering between the loop contractions is caused by the time delay needed for the ‘information’ about the loss of support to travel outwards."
The loop contractions are triggered at the same time as the flare begins emitting intense X-rays and microwaves. The three outer loops show clear oscillations even as they contract, with distinct periods and phases. After being compressed by the collapsing loops, the flaring loops oscillate until they find a new equilibrium, as indicated by the X-ray emission from the hot plasma. During the contraction a wave blast revealed by extreme ultraviolet radiation spreads away from the source of the flare.
“This presents an intriguing picture of how magnetic energy is moved rapidly around the solar corona during a flare," said Dr Simões.
Flares and CMEs are thought to be driven by a process called magnetic reconnection, in which magnetic field lines in plasma break and then re-join to field lines flowing in the opposite direction. Energy that has built up over days or months is released in just a few minutes.
In a separate study, a team from the University of Warwick has observed the first evidence that loop oscillations are driven directly by magnetic reconnection processes.
“The structure and dynamics of the solar corona can be imaged in exquisite detail and over an unprecedented range of temperatures by SDO. Oscillating loops are a useful tool for probing conditions in the corona. This offers a unique opportunity to discover the tell-tale signatures of magnetic reconnection," said Rebecca White, who is presenting the findings on Tuesday 2nd July.
The Warwick team used SDO data to study the behaviour of loops following two eruptions: a CME on 3 November 2010 and a solar flare on 8 May 2012. With the first eruption, they saw a coronal loop form below the bubble of material ejected during the CME. There appeared to be a strand connecting the CME with the top of the loop. Unusually, parts of the loop were observed to oscillate in different directions about a central pivot point.
“The loop appears to twist about a fixed point along its length. Not only is the form of this oscillation highly unusual but the coronal loop has a temperature of between 9 and 11 million degrees Celsius — this is much hotter than most loops we see, which are generally between 1 and 3 million degrees. This extreme heat has been generated by the reconnection processes," said White. “For the first time we can see a direct link between the reconnection process itself, causing the formation of the loop below the ejected bubble, and the oscillations of the loops."
The second observation showed two separate but adjacent loops oscillating in opposite directions to one another. Previous observations have shown loop oscillations caused by blast waves emanating from the flare, however this pushes the loops in a single direction.
“Again, this cannot be explained by a blast wave since this would push both loops in the same direction. We think that the oscillations here are a direct result of the flare reconnection process changing the structure of the corona between the loops and sucking them towards each. These observations demonstrate that loop oscillations are a valuable tool for studying 3D reconnection processes at work," said White.