Scientists detect major solar flare, issue storm warning April 7, 2000 Web posted at: 2:15 PM EDT (1815 GMT)

BOULDER, Colorado (AP) -- U.S. government scientists detected a major solar flare Friday and warned that geomagnetic storms could disrupt communications and knock out electrical power.

The National Oceanic and Atmospheric Administration's forecast of moderate solar storm activity was in effect through about 1600 GMT Saturday.

ALSO Solar shock wave causes surprise aurora display No immediate disruptions were reported as a result of the turbulence.

The sun is approaching the height of its 11-year cycle, although the peak had been relatively quiet until now.

The storm was rated at a moderate G-2 level on the federal government's new space weather scale of 1 to 5. Initially, the storm spiked to G-4, or severe.

Forecasters said the intense part of the storm should end late Friday, but there was a chance of another outbreak on Sunday.

Scientists said the storm originated Tuesday, although what triggered the storm was not immediately known. A cloud of electrically charged particles hurled from the sun rode the solar wind and reached Earth's magnetic field Thursday.

Eric Ort, a space weather forecaster, said he received reports from Dublin, Ireland, the display of the aurora borealis, or northern lights, was spectacular as a result of the solar storm.

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-- Martin Thompson (mthom1927@aol.com), April 07, 2000

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Solar shock wave causes surprise aurora display April 7, 2000 Web posted at: 1:14 PM EDT (1714 GMT)

From Sky & Telescope

Sky & Telescope contributing photographer Johnny Horne captured this view of the aurora from northeast of Fayetteville, North Carolina, at about 9:30 p.m. EDT. Click on image for larger view. Many skywatchers who went outside to view the moon, Mars, Jupiter, and Saturn grouped together last night were treated to a bonus spectacle -- a surprise auroral display.

According to reports sent to Sky & Telescope and also collected at the Auroral Activity Observation Network, the dramatic red display was visible across Europe and seen as far south as New Mexico and Florida.

The shock wave of solar wind hit the Earth at about 12:40 p.m. EDT and the visible display lasted until about 10:30 p.m. EDT.

Auroras most often glow green, the color emitted by oxygen atoms high in the upper atmosphere after they are struck by bombarding electrons from Earth's magnetosphere.

ALSO Scientists detect major solar flare, issue storm warning MESSAGE BOARD Stargazing Red displays are rarer, sometimes involving energized nitrogen molecules lower down in the atmosphere -- an indication of a more potent geomagnetic storm. Auroras that extend away from the poles and closer to the equator, as occurred last night, also reflect strong storm conditions.

According to Cary Oler of Solar Terrestrial Dispatch, "Although there will probably be some residual substorm activity over the higher latitudes during the next 24 hours, there will not be a recurrence of the auroral storming for most middle-latitude locations."

http://www.cnn.com/2000/TECH/space/04/07/aurora/index.html

-- Martin Thompson (mthom1927@aol.com), April 07, 2000.