subject: Solar Storm Forewarning [print this page] Researchers announced that a storm is coming--the most intense solar most in fifty years. The prediction come as of a team led by Mausumi Dikpati of the National Center for distinctive Research (NCAR). "The next sunspot cycle will be 30% to 50% stronger than the previous one," she says. If correct, the years ahead could produce a burst of solar commotion second only to the historic Solar Max of 1958.
That was a solar maximum. The Space Age was just beginning: Sputnik was launched in Oct. 1957 and Explorer 1 (the first US satellite) in Jan. 1958. In 1958 you couldn't tell that a solar storm was underway by looking at the bars on your cell phone; cell phones didn't exist. Even so, people knew something big was occurrence when Northern Lights were sighted three times in Mexico. A similar greatest now would be noticed by its effect on cell phone, GPS, weather satellites and many other modern technologies. ]
Dikpati's prediction is extraordinary. In almost-two centuries since the 11-year sunspot cycle was discovered, scientists have struggle to predict the size of future maximaand failed. Solar maxima can be intense, as in 1958, or barely detectable, as in 1805, obey no obvious pattern.
The key to the mystery, Dikpati realized years ago, is a conveyor belt on the sun.
We have incredible similar here on Earththe Great Ocean Conveyor Belt, popularized in the sci-fi movie The Day After Tomorrow. It is a network of current that carry water and heat from ocean to ocean--see the drawing below. In the movie, the Conveyor Belt stopped and threw the world's weather into chaos.
The sun's conveyor belt is a current, not of water, but of electrically-conduct gas. It flows in a loop from the sun's equator to the poles and back again. Just as the Great Ocean Conveyor Belt controls weather on Earth, this solar conveyor belt controls weather on the sun. Specifically, it controls the sunspot cycle.
Solar physicist David Hathaway of the National Space Science & Technology Center (NSSTC) explains: "First, keep in mind what sunspots are--tangled knots of magnetism generated by the sun's inner dynamo. A typical sunspot exists for just a few weeks. Then it decays, leaving behind a 'corpse' of weak magnetic fields."
Come in the conveyor belt.
"The top of the conveyor belt skims the surface of the sun, extensive up the charismatic field of old, dead sunspots. The 'corpses' are dragged down at the poles to a depth of 200,000 km somewhere the sun's magnetic dynamo can intensify them. Once the corpses (magnetic knots) are reincarnated (amplified), they become buoyant and float back to the surface." Prestonew sunspots!
All this happen with massive slowness. "It takes about 40 years for the belt to entire one loop," say Hathaway. The speed varies "anyplace from a 50-year pace (slow) to a 30-year pace (fast)."
When the belt is turning "fast," it means that lots of magnetic fields are being swept up, and that a future sunspot cycle is going to be powerful. This is a basis for forecasting: "The belt was turning fast in 1986-1996," says Hathaway. "Old magnetic fields swept up then should re-appear as big sunspots in 2010-2011."
Similar to nearly everyone experts in the field, Hathaway has confidence in the conveyor belt model and agrees with Dikpati that the next solar greatest should be a doozy. But he disagree with one point. Dikpati's predict puts Solar Max at 2012. Hathaway believes it will arrive earlier, in 2010 or 2011.
The past shows that large sunspot cycles 'ramp up' faster than small ones," he says. "I expect to see the first sunspots of the next cycle appear in late 2006 or 2007and Solar Max to be in progress by 2010 or 2011.
