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March 30th, 2009, 11:46 AM
Is this normal? Does this inactivity indicate a lull before the storm?
No. The sun is currently in the transition from sunspot minimum to maximum, an 11-year cycle. Sunspot maximum is supposed to occur in 2012. Since we are at the end of the minimum period, a spotless sun is not at all unusual.
March 30th, 2009, 04:48 PM
Space storm alert: 90 seconds from catastrophe
it is hard to conceive of the sun wiping out a large amount of our hard-earned progress. Nevertheless, it is possible. The surface of the sun is a roiling mass of plasma - charged high-energy particles - some of which escape the surface and travel through space as the solar wind. From time to time, that wind carries a billion-tonne glob of plasma, a fireball known as a coronal mass ejection (see "When hell comes to Earth"). If one should hit the Earth's magnetic shield, the result could be truly devastating.
The incursion of the plasma into our atmosphere causes rapid changes in the configuration of Earth's magnetic field which, in turn, induce currents in the long wires of the power grids. The grids were not built to handle this sort of direct current electricity. The greatest danger is at the step-up and step-down transformers used to convert power from its transport voltage to domestically useful voltage. The increased DC current creates strong magnetic fields that saturate a transformer's magnetic core. The result is runaway current in the transformer's copper wiring, which rapidly heats up and melts. This is exactly what happened in the Canadian province of Quebec in March 1989, and six million people spent 9 hours without electricity. But things could get much, much worse than that.
March 30th, 2009, 04:49 PM
The most serious space weather event in history happened in 1859. It is known as the Carrington event, after the British amateur astronomer Richard Carrington, who was the first to note its cause: "two patches of intensely bright and white light" emanating from a large group of sunspots. The Carrington event comprised eight days of severe space weather.
There were eyewitness accounts of stunning auroras, even at equatorial latitudes. The world's telegraph networks experienced severe disruptions, and Victorian magnetometers were driven off the scale.
March 30th, 2009, 04:50 PM
though a solar outburst could conceivably be more powerful, "we haven't found an example of anything worse than a Carrington event", says James Green, head of NASA's planetary division and an expert on the events of 1859. "From a scientific perspective, that would be the one that we'd want to survive." However, the prognosis from the NAS analysis is that, thanks to our technological prowess, many of us may not.
First to go - immediately for some people - is drinkable water. Anyone living in a high-rise apartment, where water has to be pumped to reach them, would be cut off straight away. For the rest, drinking water will still come through the taps for maybe half a day. With no electricity to pump water from reservoirs, there is no more after that.
There is simply no electrically powered transport: no trains, underground or overground. Our just-in-time culture for delivery networks may represent the pinnacle of efficiency, but it means that supermarket shelves would empty very quickly - delivery trucks could only keep running until their tanks ran out of fuel, and there is no electricity to pump any more from the underground tanks at filling stations.
Back-up generators would run at pivotal sites - but only until their fuel ran out. For hospitals, that would mean about 72 hours of running a bare-bones, essential care only, service. After that, no more modern healthcare.
April 3rd, 2009, 08:41 AM
Deep Solar Minimum
April 1, 2009: The sunspot cycle is behaving a little like the stock market. Just when you think it has hit bottom, it goes even lower.
It adds up to one inescapable conclusion: "We're experiencing a very deep solar minimum," says solar physicist Dean Pesnell of the Goddard Space Flight Center.
"This is the quietest sun we've seen in almost a century," agrees sunspot expert David Hathaway of the Marshall Space Flight Center.
Quiet suns come along every 11 years or so. It's a natural part of the sunspot cycle, discovered by German astronomer Heinrich Schwabe in the mid-1800s. Sunspots are planet-sized islands of magnetism on the surface of the sun; they are sources of solar flares, coronal mass ejections and intense UV radiation. Plotting sunspot counts, Schwabe saw that peaks of solar activity were always followed by valleys of relative calm—a clockwork pattern that has held true for more than 200 years: plot.
The current solar minimum is part of that pattern. In fact, it's right on time. "We're due for a bit of quiet—and here it is," says Pesnell.
But is it supposed to be this quiet? In 2008, the sun set the following records:
A 50-year low in solar wind pressure: Measurements by the Ulysses spacecraft reveal a 20% drop in solar wind pressure since the mid-1990s—the lowest point since such measurements began in the 1960s. The solar wind helps keep galactic cosmic rays out of the inner solar system. With the solar wind flagging, more cosmic rays are permitted to enter, resulting in increased health hazards for astronauts. Weaker solar wind also means fewer geomagnetic storms and auroras on Earth.
A 12-year low in solar "irradiance": Careful measurements by several NASA spacecraft show that the sun's brightness has dropped by 0.02% at visible wavelengths and 6% at extreme UV wavelengths since the solar minimum of 1996. The changes so far are not enough to reverse the course of global warming, but there are some other significant side-effects: Earth's upper atmosphere is heated less by the sun and it is therefore less "puffed up." Satellites in low Earth orbit experience less atmospheric drag, extending their operational lifetimes. Unfortunately, space junk also remains longer in Earth orbit, increasing hazards to spacecraft and satellites.
April 3rd, 2009, 08:43 AM
Modern technology cannot, however, predict what comes next. Competing models by dozens of top solar physicists disagree, sometimes sharply, on when this solar minimum will end and how big the next solar maximum will be. Pesnell has surveyed the scientific literature and prepared a "piano plot" showing the range of predictions. The great uncertainty stems from one simple fact: No one fully understands the underlying physics of the sunspot cycle.
Pesnell believes sunspot counts will pick up again soon, "possibly by the end of the year," to be followed by a solar maximum of below-average intensity in 2012 or 2013.
But like other forecasters, he knows he could be wrong. Bull or bear? Stay tuned for updates.
April 3rd, 2009, 11:17 AM
Would this also effect computer boards and chips in cars, homes and other places?
What about communications?
April 3rd, 2009, 04:16 PM
yes it has affected communications in the past
that is solar flares
now all is very quiet
April 30th, 2009, 11:04 AM
May 1st, 2009, 02:24 PM
I check this facinating forum every day.
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