[TAC] [Fwd: Re: NOAA 822]

[Hank Kohl K8DD]

I sent off an email to Paul Harden NA5N, the Solar Guru who also happens 
to be
an active QRPer.  Below is his response about NOAA 822.



-------- Original Message --------
Subject: 	Re: NOAA 822
Date: 	Thu, 17 Nov 2005 09:58:12 -0700
From: 	na5n at zianet.com
To: 	k8dd at k8dd.com
References: 	<437C8B4D.20004 at k8dd.com>



Hank, 

> >BIG SUNSPOT:  An impressive sunspot, "NOAA 822," has appeared on the
> >Earth-facing side of the sun.  Measured from end to end, it is wider than
> >Jupiter, and it is crackling with M-class (medium-sized) solar flares.

I'm not sure what "crackling with M-class flares" means.  It has produced a 
couple of C-class flares and a single M-class 2 days ago - before it rotated 
into geoeffective position to effect Earth.  It's been pretty quiet for the 
past 24 hours.

> >So far none of the explosions has hurled a coronal mass ejection toward 
> >Earth. Geomagnetic storms and auroras are possible, however, if this
> >'spot unleashes a major flare in the days ahead.

Generally, a C-class flare, and even a small M-class, will not trigger a 
significant geomagnetic event. 

> Paul ....
> Just saw this on spaceweather.com .... Sunday we are headed out for St 
> Pierre and Miquelon Islands for 9 days, which includes the CQ WW CW
> contest.  

Wow! That sounds like fun.  XYL Jan N0QT likes to work that contest, so I'll 
tell her to keep an ear out for you.  At least put one NM in the log -hi. 

> Not that we are going to cancel our trip, but what are your thoughts on
> how 822 might affect us from that far north?

Sunspot 822 is a "beta-gamma" group, meaning it has strong, developing 
magnetic field disturbances and capable of producing flares, but a small 
M-class (M1-M4) range would be the largest.  Right now, it is approaching 
the center of the sun where it CAN cause the most damage to Earth should it 
produce an M-class flare.  On the other hand, it will rotate across the sun's 
surface and be out of range from causing harm in another 5-6 days.  In other 
words, this sunspot would be of concern only for the next few days in terms 
of triggering a major geomagnetic storm.  By the time you get to St. Pierre, 
it will have rotated to the limb or backside and be of no concern. 

It's very difficult to predict what a sunspot, even a beta-gamma group, will 
do.  Some get really hot and never do a thing; other's can suddenly flare 
quite large and surprise everyone.  It's not an exact science yet. 

The thing to remember during CQ WW, if a large solar flare SHOULD suddenly 
occur during the contest, it COULD ionize the D-layer and cause a near total 
HF blackout immediately following the flare event. However, this condition 
seldom lasts longer than an hour before the bands fully recover.  It is a 
temporary condition - so don't pull the plug and go home.  Just wait.  And, 
because the flare ionized the D-layer, it means it also ionized the E/F 
layers.  So when the bands recover, the ionization of the E/F layers just 
improved reflectivity and raised the MUF for the rest of the day - actually 
improving conditions in many cases.  That might open up 10M that wasn't 
previously open. 

Those nasty geomagnetic storm triggered by a large flare takes 2+ days to 
get here, so it won't arrive until well after the contest.  The farther 
north you go, the more sensitive things are to the Earth's geomagnetic 
field.  Solar wind gets dumped into the polar regions, causing local 
disturbances and the aurora.  I don't think St. Pierre is quite that far 
north, but you may find the lower bands a bit noisier than down here. 

GL and have a great trip. 

72, Paul NA5N