From: LARRY KLAES (ljk4_at_msn.com)
Date: Wed Oct 22 2003 - 12:39:31 PDT
----- Original Message -----
From: Cary Oler
Sent: Wednesday, October 22, 2003 1:45 PM
To: sun-earth_at_SkyandTelescope.com
Subject: AstroAlert: Solar Maximum Deja Vu !
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This Is SKY & TELESCOPE's AstroAlert for Sun-Earth Interactions
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A s t r o A l e r t
Sun-Earth Alert
Solar Terrestrial Dispatch
http://www.spacew.com
22 October 2003
SOLAR MAXIMUM DEJA VU
It is an established fact that intense regions of solar activity can
occur at just about any time during the ~11 year solar cycle. Although they
appear more frequently during the years immediately around the solar maximum,
they can also occur well into the declining years closer to the solar
minimum. We are currently observing one of those periods.
Not one, but TWO intense active regions are now visible on the Sun.
The first and thus far the largest region (Region 484) was mentioned in
the last AstroAlert. It now covers an area of more than 5,200 million square
kilometers. That is larger than the surface areas of all of the inner planets
(Mercury, Venus, Earth and Mars) combined - with more than enough room left
over for an additional planet having the surface area of the Earth)! Region
484 is easily visible to the unaided (but protected!) eye.
Another active region has just rotated into view around the
southeastern limb of the Sun. John McConnell, an avid solar observer,
notified us today that this region is now visible on the limb. It's size is
still difficult to discern given its proximity to the limb. But it has proven
to be a powerful sunspot complex capable of very energetic activity.
Beginning at about 19:30 UTC yesterday (3:30 pm EDT) and while still
behind the east limb of the Sun, this region produced a long-duration flare.
The tops of the solar explosion were visible as the activity rose above the
surface of the Sun. Several hours later, at 03:24 UTC on 22 October (or 11:24
pm EDT on 21 October), this region produced a very long duration solar flare.
X-rays from this event remained above M-class levels for a remarkable 8 full
hours! The total energy released from this event was comparable to the energy
released in a typical major X-class solar flare. Coronal mass ejections were
associated with both of these events.
As this region rotates toward the Earth over the next week, it may
produce additional coronal mass ejections capable of producing stronger space
weather storms and associated periods of stronger auroral activity ("Northern
Lights").
Either of these two strong centers of solar activity are capable of
producing minor to major solar flares.
** End of the AstroAlert Bulletin **
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