A Strong Backhand Slap From End of Solar Storm
[...] The latest storm started with a flare on Tuesday, and had been forecast to be strong and direct, with one scientist predicting it would blast Earth directly like a punch in the nose. But it arrived Thursday morning at mild levels — at the bottom of the government's 1-5 scale of severity. It strengthened to a level 3 for several hours early Friday as the storm neared its end. Scientists say that's because the magnetic part of the storm flipped direction.
"We were watching the boxer, expecting the punch. It didn't come," said physicist Terry Onsager at the National Oceanic and Atmospheric Administration's space weather center in Boulder, Colo. "It hit us with the back of the hand as it was retreating."
Forecasters can predict a solar storm's speed and strength, but not the direction of its magnetic field. If it is northward, like Earth's, the jolt of energy flows harmlessly around the planet, Onsager said. A southerly direction can cause power outages and other problems.
Thursday's storm came in northerly, but early Friday switched to the fierce southerly direction. The magnetic part of the storm spent several hours at that strong level, so combined with strong radiation and radio levels, it turned out to be the strongest solar storm since November 2004, said NOAA lead forecaster Bob Rutledge. [...]
Apparently, we can only find out about the composition of the magnetic field of these flares headed toward Earth, when they come in contact with our ACE satellite which is a million miles out, monitoring this for us:
Our only solar storm warning satellite ‘could falter soon’
Washington: A US satellite that offers the only advance warnings of incoming solar storms is more than a decade past its expected orbital lifetime and is possibly on its last legs, researchers say.
Stationed around 1 million miles from Earth, NASA’s Advanced Composition Explorer satellite, nicknamed ACE, cautions about incoming high-energy particles from the sun which can wreak havoc on radio, GPS, satellite communications that are now embedded in modern life.
“It would be a very bad day for us if that spacecraft was not working,” the Discovery News quoted William Murtagh, program coordinator for NOAA’s Space Weather Prediction Center in Boulder, Colo., as saying.
“When an eruption occurs on the sun, there are still quite a few question marks as to if it’s going to hit the Earth and when it’s going to hit the Earth,.”
Until the sun’s free-flying and highly energetic outbursts, known as coronal mass ejections, hit the ACE spacecraft, forecasters are not acquainted with the orientation of their embedded magnetic fields.
Depending on the polarity, or alignment, Earth’s magnetic shield will either peel away, giving the highly charged particles more freedom to disturb electrically sensitive equipment and communications, or rebuff the particles, like what happened during this week’s outburst. [...]
The aging ACE spacecraft is scheduled to be replaced by the Triana spacecraft, which has a target launch date of June 2014. Lets hope the ACE spacecraft can last for us until then.