Following is an alert I found in my email inbox this morning via the "astroalert" function of the spaceweather site www.spacew.com/astroalert.html. This alert is brought to your attention because of the possible impact of solar activity on electrical equipment and the grid, especially at higher latitudes, as discussed in previous posts here on TB2000.

WARNING: The following alert mentions "naked eye" sunspots. DO NOT LOOK DIRECTLY AT THE SUN WITHOUT PROPER PRECAUTIONS (such as mylar glasses *specifically designed* for solar viewing, or a properly dense piece of welding glass or a telescope glass filter designed for solar viewing).

By "naked eye" the following alert means a sunspot group sufficiently large to see without magnification (i.e. without a telescope), but you still need to block out the sun's light to see the sunspots. It is largely because of such "naked eye" sunspots, plus naturally occurring fog acting as a "solar filter," that our ancestors have known about sunspots since antiquity. But unprotected investigation of sunspots is also thought to have caused eye damage to some early investigators, including Galileo. Be safe, be smarter than Galileo, don't look at the sun without proper precautions!

********BEGIN ASTROALERT*******

Potential Major | A s t r o A l e r t | 02 March 2000 Solar Flare Warning | | 04:10 UTC

------------- Sun-Earth Alert --------------- Active sunspot regions 8882 and 8891 are very large naked-eye (dont be silly enough to try to look at them directly!) sunspot groups occupying an area near 1,000 millionths of a solar hemisphere. Region 8882 is currently the most complex magnetically and now sports a delta magnetic configuration where opposite polarity umbrae exist within a single penumbra. This configuration is the most magnetically unstable and often results in more prolific solar flaring.

There is concern that further growth or development in Region 8882 may spawn a major M or X class solar proton flare. When major flares occur in regions as large as these are, they often succeed in accelerating prodigious quantities of high-energy protons toward the Earth at near-relativistic speeds. The location of Region 8882 is presently near what is known as the footpoint of the Earth. That is the location where the magnetic field near the Earth originates at the Sun. The Earth and Region 8882 are therefore fairly well connected, magnetically speaking. And since protons are charged particles that most easily follow along lines of magnetic fields, any accelerated protons released by a major solar flare would technically reach the Earth along the shortest path. As a result, energetic protons could reach the Earth very rapidly (possibly in less than 1 to 2 hours after the peak phase of the flare) and produce maximal impact with the Earths space environment.

Fortunately, the Earths atmosphere and magnetosphere shield all life at the surface from the effects of proton flares. But our technology can suffer. High densities of energetic protons can produce electrical upsets on spacecraft and can intensely ionize the lower region of the polar ionosphere, which in turn can lead to the heavy absorption of ionospherically propagated radio signals. These are some of the more extreme effects of proton flares. Most likely, any proton flaring from Region 8882 will be of much less concern.

Of additional concern is the emergence of an apparently separate bipolar sunspot group just to the north of Region 8882. If this region grows very much, it will almost certainly begin to interact with Region 8882. Such interaction may result in increased flare production and could possibly help trigger major levels of activity.

Region 8891 is also a potential powerhouse of activity. This naked-eye spot group may also contain a delta magnetic configuration within the central spot complex, although officially it is not yet described as having one. It has been fairly quiet over the last several days and has yet to produce any significant levels of flare activity. Persistence would suggest this region may continue to be quiet unless additional and more rapid growth occurs. However, it is large enough to easily spawn a major M or X class solar flare should its apparently stable magnetic configuration become disturbed.

Other solar features of interest (somewhat outside the topic of this warning) is the possible eruption of a dark solar filament located to the east of Region 8891. This filament has become quite active over the last 24 hours. Additional activity may destabilize it enough to erupt.

Amateur observers with hydrogen-alpha filtered telescopes may want to keep an eye on the northwest and southeast limbs where minor surging was also observed today. An old active sunspot region is due back to the southeast limb over the next 3 to 5 days. X-ray imagery of the southeast limb suggests a fairly small active sunspot region is likely to come into view where the surging was observed. For a map of where to find this activity, consult the image at: http://www.spacew.com/astroalert.html.

This warning will remain in effect until Region 8891 departs the west limb (in roughly one more week).

** End of AstroAlert **

-- Andre Weltman (72320.1066@compuserve.com), March 02, 2000

Answers

2 Mar 2000 Aurora Alert: On
March 1 at 0800 UT the
interplanetary magnetic field
developed a relatively strong
southward-pointing component. This
condition usually means that solar
plasma is able to penetrate Earth's
magnetosphere. Since then geomagnetic
activity has been high
(Kp ~ 4) and aurora could be visible over
the northern tier of US
states around local midnight on March 2.

SpaceWeather.com

-- spider (spider0@usa.net), March 02, 2000.