Fw: Aurora

[Jim Worsham]

Lets fire those rigs up guys!  I will be monitoring around 50.125 and 144.2
looking for aurora most of the weekend.

73
Jim W4KXY
w4kxy@bellsouth.net

----- Original Message -----
From: "Dale Parfitt" <parinc@gte.net>
To: <vhf@w6yx.stanford.edu>
Sent: Saturday, November 25, 2000 11:49 AM
Subject: Aurora


> Thought this might be of interest.  Dale W4OP
>
> Gang,
> >The sun has been EXTREMELY ACTIVE over the past day.
> >
> >#1: 24NOV 0500UTC X2 FLARE  Shock wave:  912 km/sec +CME +PROTON EVENT
> >#2: 24NOV 1500UTC X2 FLARE  Shock wave: 1200 km/sec +CME +PROTON EVENT
> >#3: 24NOV 2200UTC X2 FLARE  Shock wave: 1916 km/sec +CME
> >#4: 25NOV 0100UTC M8 FLARE  Shock wave: still being determined
> >
> >These MAJOR flares have come from region 9236, which is right smack on
> >the center of the sun, and a bit north of the solar equator.  This
> means
> >the millions of tons of solar mass ejected with the CME shockwaves is
> >heading DIRECTLY to the earth.  We will receive a direct, or very near
> >direct hit, from this activity.  Furthermore, region 9236 continues to
> >grow in magnetic complexity, meaning it is likely not done producing\
> >major flares.
> >
> >SUMMARY: We have FOUR CME's/shockwaves enroute to planet Earth right
> now
> >(and perhaps more if further flares are produced from this region).
> >
> >GEOMAGNETIC ACTIVITY ... MAJOR TO SEVERE STORMING
> SATURDAY-SUNDAY-MONDAY
> >There was an M-class flare late on 23 NOV that is expected to hit the
> >earth saturday evening in North America, triggering minor to major
> >geomagnetic storming.
> >
> >The travel time from the sun to the earth is ESTIMATED at about 70% of
> >the shockwave of the CME as it leaves the sun, as listed above.  Using
> >70%, my calculations show the arrival times will be:
> >
> >#1: 26NOV 1600UTC = SUN 26NOV 0900 MST About  650 km/sec = MINOR STORM
> >#2: 26NOV 1800UTC = SUN 26NOV 1100 MST About  850 km/sec = MAJOR STORM
> >#3: 27NOV 0400UTC = SUN 26NOV 2100 MST About 1400 km/sec = MAJOR STORM
> >                                                            TO SEVERE
> >#4: Not determined yet
> >
> >AURORAL ACTIVITY will be strong when the first two flares arrive in the
>
> >dark regions of the earth ... basically Asia.
> >
> >AURORAL ACTIVITY FOR NORTH AMERICA is expected to be strong when the X2
>
> >(#3) arrives around 9pm MST (11pm EST).  With the measured shockwave of
>
> >1916 km/sec of the CME, this suggests the arriving shockwave will be
> >1300-1400 kmk/sec.  This would be the strongest shockwave to hit the
> >earth this solar cycle if it maintains velocity.  This could trigger a
> >severe magnetic storm plus auroral well into the lower latitudes,
> >including the southern United States.  I will post updates of this
> >projection as more recent data becomes available.
> >
> >But keep in mind, these were very energetic flares releasing speed-of-
> >light protons, meaning the velocity of the shockwaves may actually
> remain
> >quite high (higher than the 70% estimate), meaning they could impact
> the
> >earth several hours before that listed above.
> >
> >HF PROPAGATION:  Right now ... solar flux is 197 and saturday's solar
> >flux will certainly exceed 200 following the effects of these flares.
> >The higher frequencies will support excellent propagation over the
> >weekend.  40M and below will experience some noise satuday evening due
> >to a coronal hole stream.
> >
> >SUNDAY ... major to possible severe storm conditions will exist the
> >entire day and into monday.  The lower ham bands will be experiencing
> >very high noise levels, if not total black out conditions.  The higher
> >bands may remain in good shape, unless we get hit with a severe
> shockwave
> >and more proton activity, which will heavily ionize the D-layer and
> >cause difficult conditions 20M and above as well.
> >
> >POLAR CAP ABSORPTION EVENT is in progress due to the arrival of the
> >energetic protons from the first two X2 flares.  HF communications in
> >the higher latitudes, such as Canada and Alaska, is already difficult
> at
> >best, and will only get worse by sunday.
> >
> >The above is a description of today's activity and an attempt to
> describe
> >the physical effects it will likely produce.  As usual, this is NOT a
> >prediction of the end of the world or anything ... just letting you
> know
> >when the bands will be good and likely bad.  Never let these events
> >keep you from TRYING the bands ... but at least you'll know what is
> >happening if you hear nothing :-)
> >
> >Frankly, this is one of the most energetic periods of solar activity
> >we've seen this solar cycle, and the potential for some real
> excitement,
> >from HF blackoouts, some great auroral displays, to possible problems
> >with satellites and power grids does exist.  Some of this activity has
> >occured following todays RSGA daily report, so much of the intensity
> and
> >NOAA's estimate of arrival times has not yet been published.  I'll post
>
> >updates following tomorrows NOAA RSGA report release.
> >
> >All the "numbers" are there for some interesting activity ... but we
> all
> >sadly know how sometimes the numbers are subject to different
> >interpretations, recounts, etc. leading to a questionable outcome :-)
> >
> >Let's all hope for some crystal clear skies sunday night to observe
> >some hopeful great auroral activity.
> >
> >72, Paul NA5N
>
>
>
>
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