WVDXA For those who don't subscribe to QRP-L

[Rick Robinson]

Link to Greenbank. Check it out after 0000Z and it will have all of 
todays activity according to this guy. 73, Rick.



-------- Original Message --------
Subject: 	[QRP-L] Todays X9 Flare
Date: 	Tue, 05 Dec 2006 13:03:30 -0700
From: 	na5n at zianet.com
To: 	qrp-l - qth.net <qrp-l at mailman.qth.net>
References: 	<4284994.1165329820410.JavaMail.root at fed1wml15.mgt.cox.net> 
<4575BB78.4010908 at jason.white.name> <4575C5AA.2070505 at cox.net>



Gang,
Today's X9 flare was indeed quite a surprise, not only to us hams, but to 
the scientific community as well.  The flare occured right on the east limb 
of the sun, that is, just coming into view, such that the active region that 
produced it has not yet been viewed.  This region will be rotating into view 
over the next day, and over the next two weeks will move across the surface 
of the sun (from east to west, or left to right on most solar images). 

Since this flare was on the east limb, Earth will experience on the 
speed-of-light emissions (ionizing radiation and the radio storms) - NOT a 
subsequent severe major geomagnetic storm.  Although, NOAA has predicted an 
A=20 (minor storm) for thursday, anticipating a glancing blow from the 
shockwave.  It will not be a direct hit.  However, over the next week and a 
half, further solar flares from region 0929/0930, as it nears the center of 
the sun, could cause major geomagnetic disturbances on Earth. 

I talked to our head solar astronomer, Dr. Tim Bastian, who said the 40-ft. 
and 300-ft. antennas at Green Bank, WVa are now mapping this area of the 
sun, trying to get some spatial resolution to see what this area looks like 
- difficult when it is right on the limb.  Additionally, there are some 
pretty images of the Type II and Type IV sweeps on their radiometer. 

He has given me permission to pass on the following information.  This is 
his website of the Green Bank solar radio burst spectrometer (GBSRBS), which 
is a newly created and EXPERIMENTAL website you might find interesting, 
though it has not been announced/released for public use yet (but released 
to QRP-L by permission).  It is at:
http://gbsrbs.nrao.edu 

Click on SELECTED EVENTS, then Type II and Type IV.
Type II sweeps are caused by the shockwave of the flare punching through the 
magnetic field lines of the disturbance.  They "sweep" from higher 
frequencies (50-300MHz) to lower frequencies (5-20MHz, depending on the 
intensity of the shockwave).  On earth, they will sound like bursts of 
static flying through your passband, much like ignition noise. 

This X9 has been producing Type II events. 

Type IV sweeps are more continuum noise generated by the solar flare, though 
bounded in frequency to the 10-100MHz or so range, though effects much 
higher are not uncommon for a large flare.  On earth, the Type IV sweeps 
causes an overall increase in the HF noise level. 

This X9 has been producing Type IV events. 

Now go to the DAILY SUMMARIES, click on DEC (December) and 2006.
Click on Dec. 05 under the "BI 12-62 MHz" column.  This is the Bruny Island 
Radio Spectrometer in Tasmania, which shows today's events so far.  Can you 
see the Type II sweeps (going from the high to lower frequencies)? And, the 
Type IV continuum noise? 

The NRAO radio burst spectrometer is also real time, however, it is not 
updated on this PUBLIC website until the end of the UTC day, so Dec.05 is a 
bit blank yet.  However, look at it later, which will give you a real-time 
(at least at the time -hi) spectrum of what happened to the HF bands down to 
12MHz.  You can compare it to Dec.04 (yesterday), which is pretty boring. 

Again, this will soon be an official NRAO (National Radio Astronomy 
Observatory) public website, and soon to have the daily real-time 
spectrograph on it, but still under development.  Dr. Bastian was kind 
enough to allow me to share it with those hams so interested. 

Lastly, Dr. Bastian is also observing, etc. to determine the effects of this 
flare to our upper ionosphere, and interested to know what effects this is 
or has had on HF propagation.  There are facilities that measure these 
things, but it will be at the end of the UTC day or later before their data 
is released.  I am at work and no access to any HF gear.  So, for those of 
you who have been on the bands since this morning, let me know (either 
private or via QRP-L) if you heard any Type II sweeps (the bursty, ignition 
noise stuff and approx. what time and frequency), an overall increase in 
noise (type IV), or if you experienced an HF black-out or near blackout 
condition.  State your approx. location. 

It is hard for some of these astronomers to realize there is a fleet of 
people out there who are experiencing these things real-time on ham radio.  
A sampling of reports across the country of noted effects could be helpful 
right now (as some of the propagation study instruments are shut down during 
the solar miniumum). 

I'll pass on anything interesting that might result from todays solar 
observing we're doing on this. 

Thanks and 72,
Paul NA5N 

National Radio Astronomy Observatory (NRAO)
Very Large Array (VLA) Radio Telescope
Socorro, New Mexico 

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