[PPRAANet] Todays NOAA RSGA Report explained

[W0rw@aol.com]

Gang,

We are still in a very violent geomagnetic storm.  K=7, 8 and 9 so far
all day.  We're still being bombarded by solar particles.  Our magnetic
field is still wiggling strongly, generating huge electrical currents
flowing along our magnetic field lines. (This is what wipes out HF with
noise).

The magnetic orientation is currently negative (-Bz), meaning our magnetic
field is still being agitated in the maximum sense.  Ideal for auroras.

We do not have to wait for a shockwave to arrive. Look north for auroral
activity as soon as the sun goes down in your area and periodically
throughout the night.  There is active aurora ongoing right now at 1600 
MDT, as the east coast enters darkness.  I don't know how far southward
it will extend, but the northern tier of states should see auroral
activity for sure.  Don't sit out in the cold until 2am waiting for
something, but I'd certainly check the northern skies every 30-60
minutes for a red glow.  If it's more active than that, the aurora then
finds you!

On Wed, 29 Oct 2003, Paul Harden wrote:

> Joint USAF/NOAA Report of Solar and Geophysical Activity
> SDF Number 302 Issued at 2200Z on 29 Oct 2003

> IA.  Analysis of Solar Active Regions and Activity from  28/2100Z
> to 29/2100Z:  Solar activity was high. Region 486 (S17W09) has
> produced another major flare, an X10 flare at 29/2049Z. This very
> large flare was still in progress at the end of the period.

An X10 is a huge VERY MAJOR FLARE.  Region 486, where the flare
occured, is in the center of the sun.  A flare that WILL impact earth 
is called GEOEFFECTIVE. This flare is highly geoeffective, and thus
WILL impact earth.

When? NOAA has not yet released it's shockwave and Type II sweep data.  
I'll post later when it becomes available.  Likely, it will be a fast 
mover as well, but probably not at 2000 km/sec like the last one.

> Associated activity and the potential impact of this flare will be
> assessed during the next period.

> Region 486 also produced an M3 at 29/0511Z. This region with 2600 
> millionths of white light areal coverage IS NOW THE LARGEST SUNSPOT
> GROUP OF SOLAR CYCLE 23. [CAPS mine - ph]

This region can produce more X-class flares over the next few days.  
Solar astronomers measure the size of a sun spot group by how much area 
of the suns surface is occupies, and is measured in terms of "millionths 
of surface coverage."

> Region 488 (N08W18) is also a large, complex active region and now 
> exceeds 1200 millionths in a beta-gamma-delta configuration. C-class 
> activity and low M-class flares were observed in this region. 

Region 488 is also geoeffective right now. The beta-gamma-delta thing
describes a magnetic complexity of the sunspot region typical when a major
flare is about to occur. In other words, this region could produce a major
flare or two in the next few days as well, and the shockwave would also
impact earth.

> IB.  Solar Activity Forecast:  Solar activity is expected to continue
> at high levels. The very large and complex Region 486 will likely
> produce more major flare activity during its remaining 5-6 days on
> the visible disk. A major event is also possible from Region 488.

As described above.

> IIA.  Geophysical Activity Summary 28/2100Z to 29/2100Z:
> The geomagnetic field ranged from unsettled to severe storming. The
> powerful CME from the X17/4b flare on 28/1110Z, impacted the Earth's
> magnetic field at 29/0613Z. The transit time for this CME was around
> 19 hours, making it one of the fastest on record. 

And you thought I was making that up :-)

> The sudden impulse measured 140 nT on the Boulder magnetometer. 

nT is "nano Teslas," a measure of the magnetic field strength.
140nT is not bad, but surprised it wasn't more than that for the
strength of the shockwave impact.

> Strong southward IMF Bz initiated severe (K9) storming at middle and 
> high latitudes in the 29/0600 - 0900Z period. Mostly northward Bz 
> occurred from 29/0900 - 1800Z; however, major to severe storming 
> persisted. A sharp southward turn in the Bz occurred at around 1800Z 
> ending the period with K8-9 severe storming.  

IMF = Interplanetary magnetic field. This is what I was trying to
describe yesterday. If it remains northpointing (+Bz), the effect of the
impact is minimized. When the direction of the IMF, due to the impact,
turns southward (-Bz), the geomagnetic storm becomes immediately severe.
Had the impact hit us last night with a -Bz, we would have had a heck of
a storm with auroras very far south and you probably would have had an
excellent view with most of the power grids down as well -hi.

The shockwave from the flare contains millions of tons of solar particles.
It has a magnetic field of it's own. It is this IMF of the shockwave, and
the orientation of its field that +Bz and -Bz is referring to. A -Bz, when
it impacts the earth, is opposite to the orientation of the earths
magnetic field and causes the maximum disturbance.

> The large proton event and GLE that followed the X17 flare is now in 
> decline. 

GLE = Ground Level Event. The protons striking the earth are energetic
enough that they are penetrating to the earths surface, creating the GLE
classification. This does happen with major flares, but not all that
common. A quasi-rare event. Keep in mind, this can be ionizing radiation
to plants, animals and people. Our QRP friends in Canada and Alaska may
have a nice tan tomorrow and not know why.

> The greater than 10 MeV proton event that began on 28/1215Z, peaked at 
> 29/0615Z at 29,500 pfu, making it the second largest greater than 10 MeV
> proton event this cycle 

This flare was definitely a record breaker.
pfu = proton flux units.

> IIB.  Geophysical Activity Forecast:  The geomagnetic field is
> expected to continue at severe storm levels through day one. The IMF
> Bz is now sustained southward at near -30 nT, resulting in severe
> storm levels. This condition is expected to persist through at least
> the first half of day one. 

In addition to -Bz causing a continuation of the geomagnetic storm, it
also means a CONTINUATION FOR AURORAL ACTIVITY tonight over North
America. You don't have to wait for a shockwave to arrive.  Just look at
the sky periodically shortly after sundown to whenever.

Goto:
http://www.sec.noaa.gov/pmap/index.html

This is a map showing the extent of the aurora nearly real time.  If it's
RED to your north, aurora is possible. The closer the red is to you, the
higher the possibility of it being visable in your area.  Keep in mind,
the red auroral being displayed is actually tens of miles up in the sky.
It doesn't have to be over your head to see it.  If the blue portion of
the auroral oval is south of you, you have a high probability of seeing
auroral activity.

> The potential geomagnetic impact from today's X10 flare will be 
> assessed next period; predictions for days two and three will likely 
> change considerably.

Again, pending their determination of the speed of the shock wave, and
hence when it will impact earth.

> III.  Event Probabilities 30 Oct-01 Nov
> Class M    90/90/90
> Class X    50/50/50
> Proton     99/99/75

A 50% chance of more X class flares is quite high odds!

> PCAF       in progress

PCA = Polar Cap Absorption event, in progress. Our friends up north are
in a near HF blackout right now.

> IV.  Penticton 10.7 cm Flux
> Observed           29 Oct 279
> Predicted   30 Oct-01 Nov  275/265/260
> 90 Day Mean        29 Oct 126

When things settle down, the huge boost in solar flux from all of this
will allow good DX propagation on the higher bands for awhile.

> V.  Geomagnetic A Indices
> Observed Afr/Ap 28 Oct  015/020
> Estimated Afr/Ap 29 Oct  120/150
> Predicted Afr/Ap 30 Oct-01 Nov  080/100-020/025-010/010

The K index (1-9) is measured every 3 hours. The A-index is a DAILY
index, averaging readings over the 24 hour period. This is why the A-index
shown for today was only 20. This was actually YESTERDAY's A-index. Todays
A-index AVERAGED 150 (Ap means the overall PLANETARY A-Index), even though
portions averaged up to 400 for awhile (the 3-hour periods, measured
similar to the K-index). The definition of the A-index is the planetary
AVERAGE over the past 24 hours in the UTC day.

 Paul Harden from the VLA
via LBO