[PPRAANet] X1 Flare 1/15

[W0rw at aol.com]

Gang,

My "homepage" is the NOAA site, http://www.sec.noaa.gov/today, and I

almost fell off my chair a few moments ago when I noticed the *X1*

flare earlier today.  This is VERY unusual for this late in the solar

cycle, and you can bet it will effect the HF bands over the next few

days. Some good -- some bad. 


Today, 15 JAN 2005 (so far)

0022 UTC X1 flare from region 0720

0426 UTC M8 flare from region 0720

0554 UTC M8 flare from region 0720

1408 UTC M3 flare from region 0718 


Here's what's important: both solar regions 0718 and 0720 are currently

right on the central meridian, the smack center of the sun.  These flares

are all GEOEFFECTIVE, meaning the electrons and protons blasted out from

the flares will head directly at Earth.  Some of the energetic electrons

and protons are hitting the Earth right now - those that are traveling

near the speed of light.  The shock waves from these flares, traveling

far less than the speed of light and riding along with the solar wind,

will arrive later, probably late sunday and monday. NOAA has not yet

posted the estimated shock velocity, which could be anywhere from 800

to 1500 km/sec.  Usually, a shockwave around 1000 km/sec or more will

trigger MAJOR to SEVERE geomagnetic storms.  Since the flares are in the

center of the center, we will get more or less a direct hit, not a

glancing blow.  We will no escape the effects of these flares! 


THE GOOD NEWS

These flares have increased the solar flux to 130. The background X-ray

of the sun right now remains high, which could elevate the solar flux

higher over the next day or two.  This means the Earth is now receiving

higher than normal ionizing radiation.  Our E and F layers are getting

highly ionized, making them very reflective and raising the MUF.  Right

now, the MUF is around 20 MHz.  This means 15M should be open.  I can't

wait to get home and see for myself.  (I'm at work for a couple more

hours - rats!).  It also means 20M will remain open longer for the next

couple of days following sundown and supporting long skip hops. 


Between NOW and when the shockwave of the X1 hits us is a great time to

play around the bands, the higher bands, and work some DX and paths that

have not been available for awhile.  If it sounds cruddy now, try again

a bit later.  Take advantage of the highly ionized E/F layers and the

elevated MUF while it lasts. 


THE BAD NEWS

This ionizing radiation is also penetrating our atmosphere to where it

is also ionizing our D-layer.  We know that in order for our signals to

reach the E/F layers to skip back to earth, our signals must also pass

through the D-layer - TWICE.  So, enhanced ionization of the D-layer

means HIGHER than normal daytime absorption to our signals.

Here's what the D-layer absorption currently looks like:

10MHz  3dB (that's half your power!)

5MHz  7dB

3MHz 18dB 


That means 30M, 40M and 80M are nearly worthless right now with very

high absorption to your QRP signals.  The good news is this will come

to an end as soon as the sunsets in your locale, when the D-region

virtually ceases to exist anyway. 


The solar flares are also proton events, meaning they are hurling protons

at us.  As they hit the earths magnetic field, they tend to follow the

field lines and dump into the polar regions.  This means our friends in

northern latitudes are likely in a near HF blackout right now, called

a Polar Cap Absorption event, or PCA.  Sorry.  Of course, this also

fuels aurora. 


THE SHOCKWAVE

When the shockwave of this X1 hits us mid-day sunday (estimated) or

beyond, it will compress and distort our magnetic field, the magnetic

"bubble" the Earth resides in, triggering a major geomagnetic storm.

Then a few hours later, the shock wave of the M8 hits us, then a few

hours later - the other M8 shockwave will hit us.  This will keep our

geomagnetic field in storm conditions for a very prolonged period of

time, probably into tuesday.  It will also cause enhanced aurora, so

if you live in the northern U.S. states, you *could* be treated to the

northern lights, depending upon the time of the day it hits us.  For

maximum effect in the U.S., the shockwave needs to hit around local

midnight to blow all those energetic electrons over the magnetic field

lines above your head.  So keep an eye on when the shockwave hits if

you are interested in the aurora.  There's always a chance, with the

proper geometry and timing, the aurora could extend well into the

middle latitudes.  Too early to tell, and always hard to predict.

Just a heads up. 


SUMMARY.

The enhanced solar radiation has raised the MUF and made the E/F layers

very reflective for some interesting 20M and 15M DX work right now

during daylight hours.  This same radiation is also causing high

absorption to the D-layers, meaning during the DAYLIGHT hours, 10MHZ and

above will be improved over the normal right now, while 10 MHz and

below will have periods of almost blackout conditions. 


DURING THE NIGHT, the ionizing radiation stops, returning the D, E and

F layers to normal, for fairly good conditions on 40M and below.  The

higher solar flux means 20M will stay open longer than usual. 


When the shockwave hits, it will virtually wipeout 10MHz and below,

regardless of the time of day.  The effects lessen as you go up in

frequency, such that during the day, inspite of the geomagnetic storm,

20M and 15M may still be open and useful, although a little extra noise. 


This is an unusual situation for this late in the solar cycle.  Hopefully

the above information will allow you to take advantage of it where you

can, and avoid it where you must (or, at least be aware why the bands

are lousy).  I'll try to post if anything else significant occurs or

develops over the weekend. 


Paul NA5N 
via w0rw