Tuesday, November 8, 2011

Intense Northern Lights Expected This Week

Anticipation mounts after this weekend's solar flares, which could not only set off a brilliant aurora display but also disrupt communications

SUNSPOT 1339 can be seen at the top of this image (courtesy of NASA's Solar and Heliospheric Observatory). The sunspot was positioned close to the sun's left edge on Friday.sunspot 1339 on sunImage: NASA
Anticipation is mounting that soon the world will be treated to an incredible light show with a sunspot bubbling with activity.

Spaceweather.com
reports that theunusually large sunspot unleashed at least five M-class solar flares since Saturday and has a "delta-class magnetic field that harbors energy for X-class flares."

Solar flares are ranked by NOAA's SpaceWeather Prediction Center (SWPC) based on their x-ray energy output. M-class solar flares are the second strongest with X-class flares sitting at the top of the list.

The sunspot sparking an X-class solar flare, however, would not necessarily translate to enhanced northern lights (called southern lights in the Southern Hemisphere).

A coronal mass ejection, or CME (a cloud of charged particles), must follow the solar flare in order for the Earth to witness a magnificent light show with communication disruptions also a possibility.

Joe Kunches from SWPC told AccuWeather.com that in some cases a CME is never produced.

Even if a CME occurs, it may not head to Earth, as was the case last Thursday. With the sunspot situated on the sun's outer edge (from Earth's viewing point), the CME that was unleashed took aim on Mercury and Venus instead.

The Earth has a better chance at feeling the effects of a CME through midweek as the sunspot rotates with the sun and faces toward Earth.

If the sunspot erupts and an Earth-bound CME is produced, Kunches reports that it could reach the planet in as little as 18 hours, or as long as three or four days.

The strength of the eruption determines the speed of the CME, which NOAA can calculate based on observational tools currently in place.

From these calculations, NOAA can then estimate when the CME will reach Earth. The accuracy of such predictions, according to Kunches, has improved to within five hours of its actual arrival.

AccuWeather.com Astronomy Blogger Mark Paquette will continue to provide updates on any eruptions.

In the event a CME is expected to reach Earth, be sure to check your local AccuWeather.com forecast to find out if rain, snow or clouds will obscure your view of what promises to be a magnificent light show.

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