Extreme Solar, Geomagnetic Conditions Persist as Third Recent CME Hits Earth
 Sunspot 486, the large bright mass in the southeast
quadrant of this picture, is responsible for the Sun's violent solar activity
this past week. Both it and sunspot 488 (directly above 486) are capable of
continued X-Class solar flares. [NOAA, SOHO-MDI, Photo] |
NEWINGTON, CT, Oct 30, 2003--Old Sol's not finished with us just yet. A severe geomagnetic storm began at 1700 UTC today as particles from yet another coronal mass ejection enveloped Earth after being ejected by a massive X10-Class explosion in the sun's atmosphere yesterday evening, according to Spaceweather.com. This is the third CME to either directly hit or glance off the Earth in a week.
The current storm could affect the MF and HF radio spectrum, along with causing surges in power grids in higher latitudes, disrupting HF airline frequencies, and causing disruption and damage to satellite communications. The Space Environment Center of the National Oceanic and Atmospheric Administration (NOAA) reports that extreme space weather conditions could continue through Friday.
 W1AW Station Manager Joe Carcia, NJ1Q, monitors solar flare activity at
ARRL's headquarters station during Wednesday's events. Carcia monitored 20.1
MHz, a frequency mainly used to monitor geomagnetic activity on Jupiter, but
also useful for studying conditions on the Sun. [Dave Hassler, K7CCC, Photo]
|
W1AW Station Manager Joe Carcia, NJ1Q, said bulletin and code practice operations seemed unaffected by the solar events. He said no calls or e-mails have been received complaining of a lack of signal. Carcia said he monitored W1AW from his home the evening of October 29 and noted only a slight watery quality to the station's transmissions caused by the presence of aurora borealis.
Thursday at 1800 UTC, the solar flux index stood at 279, and the mid-latitude A index at an astounding 180. The planetary K index has fluctuated between 5 and 9--the top of the index's logarithmic scale--in the past 24 hours. The extreme solar activity has resulted in aurora being seen as far south as Texas on Wednesday night, along with periods of HF radio blackout. NOAA predicts blackout conditions in some higher-latitude areas for Thursday evening, with another night of the Northern Lights expected for much of the continental US.
The solar explosions originate from sunspot 486, an area roughly 10 times the surface area of the Earth. Sunspot 488 is not quite as large, but it also presents the possibility of exhibiting X-class solar flares. The solar particles streak from the sun at over 5 million MPH, according to NOAA. Associated with the geomagnetic storms--the latest classed G5, or "extreme"--are solar radiation storms. Wednesday's event caused an S4-level radiation event; some people flying in high-altitude jets may have received exposure equivalent to several chest x-rays.
Page last modified: 10:55 AM, 31 Oct 2003 ET
Page author: awextra@arrl.org
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