Space forecasters said today's solar storm is having relatively weak effects this morning, lessening the chances of disturbances to satellites or the grid. The event, however, is ongoing and still could cause problems.
A solar flare from an active spot on the sun Tuesday caused a coronal mass ejection (CME), where high-energy gases from the sun break off and hurtle off into space. This morning, this blast struck Earth in a storm which could last until tomorrow.
NOAA's Space Weather Prediction Center yesterday had forecast it to be a strong geomagnetic storm but so far it's been mild. That's good news for grid or satellite operators, which monitor these solar storms for possible disturbances, said Joe Kunches, a NOAA physicist, during a conference call with reporters.
By some measures, this storm is one of the strongest in years. The reason for the weak effect so far, though, is the orientation of the magnetic field embedded in the CME, he explained.
When there is a CME, it hits the Earth with solar particles and magnetic fields. Very strong magnetic fields can disturb the Earth's own magnetic field, the cause of possible communications problems or power surges in the grid.
In today's solar storm, however, the orientation of the magnetic field embedded in the CME is in line with the Earth's magnetic field. When the fields align, it softens the blow of any geomagnetic storming, Kunches explained.
Using a baseball analogy, Kunches said the magnetic field is like the spin on a pitched ball. "We did estimate where the pitch was going and when it was going over the plate, but we missed the spin on the ball," he said.
The first tool space forecasters at NOAA have for measuring the actual impact of solar flares is NASA's Advanced Composition Explorer (ACE), a satellite which is about one million miles from the Earth. (The sun is 93 million miles away.) The problem is that they can only determine orientation with the ACE satellite, which is when the CME is relatively close. Scientists in the field recognize as a "huge problem," Kunches said.
The solar flares and CMEs that occurred this week originated from a region that is expected to be active for days to come, he added.
The sun is approaching a solar maximum, a cycle of heightened solar flare activity that is predicted to peak in 2013. That means that space forecasters will be busy in the months ahead. Scientists are blessed with much imagery of solar activity online, but the tools for space forecasting aren't always as good as they'd like, Kunches said.
"We do worry about crying wolf," he said. "The trick is to ferret through those somewhat seductive images of bright spots (on the sun) and try to understand out of all what is the bit of information that will cause some problems on Earth."