Thursday, March 8, 2012
Radiation from solar storms begins to hit Earth
A solar flare is a sudden brightening observed over the Sun surface or the solar limb, which is interpreted as a large energy release of up to 6 × 1025 joules of energy (about a sixth of the total energy output of the Sun each second) or 160,000,000,000 megatons of TNT equivalent, over 25,000 times more energy released from the impact of Comet_Shoemaker–Levy_9 with Jupiter. The flare ejects clouds of electrons, ions, and atoms through the corona into space. These clouds typically reach Earth a day or two after the event
"The shock has arrived!"
At about 5:45 a.m. Eastern time Thursday, the geomagnetic storm from a massive solar flare that rippled the surface of the sun on Tuesday night finally reached the Earth's atmosphere.
The Facebook page for the National Oceanic and Atmospheric Administration NWS Space Weather Prediction Center made the announcement. But so far, the storm has been a bit of a dud.
That's good news for people who like their GPS accurate and their flights on time.
Space-weather enthusiasts monitored the storm at sites such as SpaceWeather.com, which said Thursday morning that the "impact was weaker than expected," causing only a "mild" geomagnetic storm. The site also said the storm could "intensify in the hours ahead."
Severe solar storms can wreak havoc with GPS navigation systems, force airlines to reroute flights and even knock out major power grids.
Grids were A-OK as of about 10:45 a.m. Eastern (7:45 a.m. Pacific), according to Kimberly Mielcarek, spokeswoman for the North American Electric Reliability Corp., which monitors the nation's major power grids.
The solar storm "has had no impact on the bulk power system," she said in an interview with The Times on Thursday morning. But utilities "continue their normal monitoring pattern ... for any abnormal energy flows."
Alex Young, a solar physicist at NASA Goddard, told The Times on Thursday morning that the storm was low level. It did, however, create some great auroras -- those gorgeous light displays in the sky -- as far south as the Great Lakes region, he said.
Although this solar storm fell short of predictions, you may want to brace yourself for the years ahead.
Solar flare activity and its fallout on Earth are expected to heat up. We're only about four years into the current 11-year solar cycle.
Young said that, around 2013, solar activity is expected to peak with “a couple of CMEs a day.” That’s coronal mass ejection – the mass of magnetized material that the sun hurls out after a flare. “But they have to be pointed at Earth. ... We would expect a couple a week to reach the Earth.”
These are unlikely to be massive geomagnetic storms. The colossal storms are expected farther into the cycle, perhaps in 2014, Young said. Large flares and their storms tend to happen as a solar cycle wanes.
He likened the solar flare activity to the release of energy with earthquakes -- “a lot of small ones ... and then every so often the big one.”
With a colossal solar flare, "radio blackouts and things like that" happen fairly immediately after the flare, Young said in an earlier interview with The Times.
Those geomagnetic storms and "can last six to 12 hours," Young said, "but the largest ones can last for days."
Source : http://www.latimes.com/news/nation/nationnow/la-na-nn-solar-storm-20120308,0,1357976.story