Potent Solar Flare — Auroras Friday?
By: Kelly Beatty
Sky and Telescope
September 10, 2014
This afternoon a powerful X-class flare ripped through the Sun's lower atmosphere and sent a blast wave directly toward Earth that should arrive early Friday morning.
Solar flare on September 14, 2014
The Sun erupted with an X-class solar flare on September 10, 2014, as captured by an X-ray imager aboard NASA's Solar Dynamics Explorer. (Blue color is artificial.)
Solar physicists believe that the Sun's current 11-year-long activity cycle peaked weakly last year and has already started to decline. But today our star sent a powerful reminder that, paraphrasing Monty Python, "I'm not dead yet!"
On Wednesday afternoon, the Sun erupted with a powerful flare that peaked at 1:48 p.m. Eastern Daylight Time. From its perspective in space, NASA's Solar Dynamics Observatory captured the titanic explosion, which covered an area several times larger than Earth.
SDO time-lapse images, recording X-ray emission at 193 angstroms from highly ionized iron atoms, show the blast wave rippling across the entire solar disk:
According to NOAA's Space Weather Prediction Center (SWPC), the flare was an X-class event — the most powerful — and it unleashed a torrent of relativistic particles and X-rays that swept over Earth minutes later.
Meanwhile, observer Steven Souza (Williams College) happened to witness the flare while viewing the Sun through a telescope equipped with a hydrogen-alpha filter. "He called me a little after 1:30 to say I should hurry upstairs," recalls his colleague, solar expert Jay Pasachoff. "Looking through the telescope, I could see the normal red disk of the Sun, but in its midst I saw a tremendously bright 'S' shape. It was on the left side of a dark spot, presumably the underlying sunspot, and there was an arc more-or-less completing a circle on the right side. The S-shape reminded me of the 'sigmoids' that my Caltech post-doc advisor, Harold Zirin, had proposed as a sign of flare-worthy active regions."
A half hour later, the bright regions were still visible but less prominent. It was, Pasachoff notes, "the brightest H-alpha flare I have ever seen (in contrast with the rest of the solar disk)."
Solar physicists have been monitoring Active Region 2158, and its potential for dramatic flares, ever since it rotated into view 5 days ago.
The X-1.6 eruption came from a sunspot group known as Active Region 2158, situated very near the center of the solar disk. "It's pretty clear there was a large coronal wave," notes C. Alex Young, an associate director in the Heliophysics Science Division at NASA's Goddard Space Flight Center, with a coronal mass ejection (CME) directed squarely at Earth.
Based on the initial SDO imagery, Young estimated that the CME could have a velocity of up to 2,000 miles (3,000 km) per second, very fast as solar storms go. Later imagery from the Solar and Heliospheric Observatory (SOHO) showed the expanding blast wave escaping as a rapidly expanding halo around the Sun's entire circumference — a clear indication that it's headed our way.
Later, however, Young sent Sky & Telescope an update: the CME's initial velocity was less than initially thought, about 875 miles (1,400 km) per second. Therefore, the shock front now crossing interplanetary space should reach Earth on Friday at about 12h Universal Time (5 a.m. Pacific Daylight Time). The SWPC's predicted geomagnetic disturbance is G3, a medium-intensity level that could trigger auroras over locations roughly northward of latitude 45° north (Oregon, Illinois, New England, and northern Europe).
AR 2158 was also responsible for a lower-intensity eruption yesterday. Although not headed directly at Earth, that predecessor could create a partial clearing in the interplanetary medium that would allow today's blast to reach us sooner that it otherwise would.
Solar flares occur in areas of concentrated magnetic fields in and above active regions. Contorted bundles of field lines can reconnect suddenly and violently, releasing vast amounts of stored energy in an abrupt "explosion" that propels blobs of the solar atmosphere outward. A powerful "super storm" in July 2012, perhaps the most energetic in 150 years, directed a perilously strong CME into space that fortunately missed Earth.
Click to watch: http://www.youtube.com/watch?v=GoK6NDkVcbE
Solar flares can cause us to be nervous, anxiousness, worrisome, jittery, dizzy, shaky, irritable, lethargic, exhausted, have short term memory problems and heart palpitations, nauseous, queasy, and to have prolonged head pressure and headaches.
We began noticing many different symptoms. Time and space seem to be on a wobble even more erratically than before. We seem to be losing track of time easily. We lose words when we are speaking. The day simply disappears as time is moving quickly. Many are experiencing insomnia, and strange dreams. We are feeling immense power surges in the body followed by energy drops. There were numerous reports of nausea, and body aches and pains and dizziness. Many feel deep grief. Some feel as if they were walking on water (ungrounded). Others said that when they closed their eyes at night, everything is spinning. There have been visual disturbances, inner ear issues, ringing in ears, throat and thyroid issues, cold feet and even a unusual symptom of having tongue dryness. Are you experiencing any of this? This isn't anything to be afraid of, just be aware of what is happening and get extra rest and drink lots of water. This too shall pass.