[HATS] Solar Storms and HF Blackouts

[Ed Manuel (N5EM)]

To all those of you who will be operating HF over the next few days,
including those preparing to drive to Arlington for HAMCOM hoping to get in
some good HF DX, sorry but here is the real news . . . .

Ed, N5EM
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From: "Paul Harden, NA5N" 

Subject: [PROP] Solar Storm Update 
 

Gang, 
Tuesday, 3 major flares on the sun (an M-class and 2 X-class) were 
positioned such that the shock waves will impact the earth. While we have 
seen several X-class flares this solar cycle, none have been positioned in 
the center of the sun to impact us this directly. The next few days, 
starting thursday evening, should be very exciting as the shock wave from 
these 3 flares reaches us, triggering some major geomagnetic storms and 
possible auroral activity into the center of the U.S. How strong of an 
effect we'll experience will become more obvious as the shock wave gets 
closer and satellites measure it's passage.
If it triggers an extremely severe geomagnetic storm, then power grid 
failures, damage to satellites and things like that are possible as well.
For QRPers/hams, the bands will be pretty much trashed for the duration 
of these geomagnetic storms, from around late thursday into the weekend. 
HF blackout conditions may also occur.
Below is tuesday's report on solar and geomagnetic activity of these 
events, commented for those so interested. I'll post these daily reports 
for the next few days, as this is truly a major solar/HF propagation event 
that occurs only a few times during most solar cycles.
72, Paul NA5N 
------------------------
> JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY 
> SDF NUMBER 158 ISSUED AT 2200Z ON 06 JUN 2000
> IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 05/2100Z 
> TO 06/2100Z: SOLAR ACTIVITY WAS HIGH. THREE MAJOR EVENTS OCCURRED IN 
> THE PERIOD, ALL FROM REGION 9026 (N20E10). A X1/2B FLARE WITH AN 
> ACCOMPANYING 560 SFU TENFLARE OCCURRED AT 06/1339UT. THIS EVENT WAS 
> FOLLOWED BY AN M7/2N EVENT AT 06/1401UT. THE LARGEST EVENT OF THE 
> PERIOD WAS AN X2/3B FLARE AT 06/1525UT.
The above is describing the 3 flares. 
An M-class flare is a MAJOR flare 
An X-class flare is an EXTREMELY major flare (largest class of flares)
> THIS EVENT ALSO PRODUCED A TYPE II SWEEP (1189 KM/S),
There are various types of "radio storms" that occur during and 
shortly after a major flare. A Type II sweep is a phenomenon caused 
by the shockwave of the flare passing through the sun's magnetic 
field lines, generating radio energy. It will sweep from a very 
high frequency (hundreds of MHz) downward (into HF) about 2 MHz 
per second. By measuring the lowest frequency of the sweep as time 
goes on, one can determine how far away from the sun the shockwave 
has traveled and how fast it is traveling. In this case, measure- 
ments of the radio sweeps indicate the shock wave is traveling 
nearly 1200 km/second. That is a VERY energetic shockwave. It 
will slow down some, but will likely hit the earth in the 900 km/sec 
range, more than sufficient to trigger a major geomagnetic storm and 
aurora.
> A FULL-HALO CME WAS CREATED BY 
> THIS EVENT AND WAS MONITORED BY THE LASCO/EIT SPACECRAFT TODAY.
A CME (coronal mass ejection) is the MASS from the sun being blown outward 
by the force of the flare. The particles get trapped in the magnetic 
field lines of the DISTURBANCE (not the sun's field lines) which forms 
a halo appearance. This "halo" of particles, in this case, escaped the 
sun and is what is now headed toward us ... a shock wave of high velocity 
and high particle density that will compress our magnetic field when it 
hits, triggering a geomagnetic storm.
> REGION 9026 REMAINS A LARGE REGION (800 MILLIONTHS) WITH AN "F" TYPE 
> BETA-GAMMA-DELTA CONFIGURATION. 
A BETA-GAMMA-DELTA configuration means there are intense magnetic field 
lines running between the sunspots inside this region in very complex 
fashion ... indicative of further major flare activity is possible. This 
is interesting in itself, since this region has thus far produced 3 major 
flares and yet the region shows no sign of decay yet. Hmmm...
> IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY IS EXPECTED TO BE AT 
> MODERATE TO HIGH LEVELS. REGION 9026 CAN BE EXPECTED TO CONTINUE TO 
> PRODUCE M-CLASS EVENTS ALONG WITH ISOLATED X-CLASS FLARES.

> IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 05/2100Z TO 06/2100Z: 
> THE GEOMAGNETIC FIELD WAS MOSTLY UNSETTLED TO ACTIVE WITH A SINGLE 
> PERIOD OF MINOR STORMING AT MID-LATITUDES FROM 06/18-2100UT.
This short period of geomagnetic storming was due to the arrival of 
solar particles from a coronal hole, and had nothing to do with all the 
flare activity.
> THE D-REGION 
> ABSORPTION FROM THE INTENSE (X2) X-RAY EVENT EXTENDED TO THE POLAR 
> CAP REGIONS OF THE DAYLIGHT SIDE OF THE EARTH.
This is due to the ionizing radiation from the X-class flares, which 
penetrated far into our atmosphere, stripping electrons off molecules in 
the D-layer. All of these free electrons in the D-layer causes higher 
than normal absorption to HF signals trying to get through to the E and 
F layers, and thus produces near blackout conditions. This effect will 
be worse the lower in frequency you go.
> IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD IS 
> EXPECTED TO BE MOSTLY QUIET TO UNSETTLED FOR THE FIRST DAY OF THE 
> PERIOD WITH POSSIBLE ISOLATED ACTIVE PERIODS. ACTIVITY SHOULD 
> INCREASE TO ACTIVE TO MINOR STORMING ON THE SECOND DAY OF THE 
> PERIOD, DUE TO THE ARRIVAL OF AN EARTH-DIRECTED FULL-HALO CME, AS 
> DESCRIBED ABOVE. ACTIVITY SHOULD INCREASE ON THE THIRD DAY TO MAJOR 
> STORM CONDITIONS, ESPECIALLY AT HIGHER LATITUDES.
Day 3 will be friday, June 9th, when the shock waves from the 3 major 
flares will arrive, triggering a MAJOR geomagnetic storm, with some 
estimates being a SEVERE geomagnetic storm. It all depends on the speed 
and density of the shock wave, and how directly it may (or may not) hit 
the earth. As a minimum, it will be a MAJOR storm.
> PCAF YELLOW <--- An alert for a Polar Cap Absorption event in the 
higher latitudes, like Alaska. If the proton 
flux increases as a result of these flares, we 
will see high D-layer absorption in the middle 
latitudes and total absorption (blackout) in 
the higher latitudes.

> IV. PENTICTON 10.7 CM FLUX 
> OBSERVED 06 JUN 186 
> PREDICTED 07 JUN-09 JUN 185/195/210 
> 90 DAY MEAN 06 JUN 189
> V. GEOMAGNETIC A INDICES 
> OBSERVED AFR/AP 05 JUN 022/026 
> ESTIMATED AFR/AP 06 JUN 018/018 
> PREDICTED AFR/AP 07 JUN-09 JUN 015/018-030/035-050/075 
^^^^^ ^^^^^ ^^^^^ 
Estimated A-index for: WED THU FRI


Solar Update: 7JUN 1800UTC

Region 9206, now smack on the sun's meridian, produced yet another 
X-class flare (X.1) about 1530 UTC today. The shock wave from this 
flare will hit the earth around mid-to-late day saturday, pretty well 
wiping out the weekend! This means there will be major geomagnetic 
storming and near to total HF blackouts from thursday evening (from 
tuesday's flares) throughout the weekend, virtually continuously. This 
will also produced enhanced auroral activity, for which predictions of 
the extent of the "auroral oval" will be issued by agencies later and 
I'll repost here.
PROTONS. Also a few hours ago, the proton flux reaching the earth has 
exceeded alert thresholds. This means D-layer absorption will be getting 
very high in the middle latitudes (which will appear as an HF blackout 
on lower frequencies, less than 10-14 MHz) and a full-scale Polar Cap 
Absorption Event (PCA) in the higher latitudes. This basically means 
our friends in Alaska will be in the "dark" for many days will very high 
absorption to HF signals.
And the real effects of all of this, namely the arrival of the shock 
waves, is still more than a day away!!!
72, Paul NA5N



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