WO steckt der X 1.6 - 19/1630 UT ???

[Herwig, Rostock]

Hallo,

ich bin echt neugierig, ob die Frage noch eine Antwort bekommt.
Hab aus dem STD-Forum mal die entsprechenden CME-Beiträge kopiert.

Nächster Kandidat in wenigen Minuten: RSGA

Name: TSobiech
Date: Sat, 20 Oct 2001 19:19:14 -0600
Subject: confused

I was under the impression that the first X.1 was going to impact sometime early on the UTC day of
Oct 21, but now all the estimates are for early on UTC Oct 22.
That's an awfully slow CME isn't it? Can someone please clarify the situation. I'm really hoping for
early UTC Oct 21, because I have crystal clear skies tonight.

Name: Cary
Date: Sat, 20 Oct 2001 21:36:20 -0600
Subject: Re: Arrival times

Hi all. Just thought I'd interject a few things.

TSobiech, the arrival time is indeed for the late UTC day of 21 October or the early UTC day of 22
October. Our initial prediction
(which we are still holding as our primary prediction) was for around 03:00 UTC on 22 October (not
21 October as some have thought).

Ulrich, you're pretty much bang on. CME brightness is not necessarily a sign of energetics. Very
strong CMEs do tend to be brighter, but
then they are often denser ejections of mass as well. Very dim CMEs can also be rather influential
when they hit the Earth. So you can't
necessarily tell geoeffectiveness from CME brightness. We wish it were that simple.

When examining LASCO images/movies of coronal mass ejection events, everyone should keep in
mind that each one has its own
'personality'. Some are bright or have wide cone angles where much of the ejected masss may be
dispersed or spread out. Others may
be dim or have narrow cone angles where more of the ejected mass is concentrated in a smaller
spatial region. There is reason to
believe (Ulrich alluded to some of them) that the first CME event had a narrower cone angle with a
trajectory very much centered
toward the Earth. Just as it is difficult (if not impossible) to tell how fast a train is moving toward
you while standing on the railroad tracks,
it is difficult to tell how fast an Earthward directed CME with a narrow cone angle is travelling
toward the Earth. Type II shock velocity
measurements suggest the CME may have been travelling a fair bit faster than LASCO image
analyses suggested (again, due to the
suspected narrower cone angle).

Thus far, it appears the disturbance is about a day away from impacting, which would ring true with
predictions for late on 21 or early on
22 October (UTC time).

Time will tell...

Name: Cary
Date: Sat, 20 Oct 2001 22:18:58 -0600
Subject: Ooops...

Tsobiech, I see why you are confused now... our Forecast Notes section stated an impact would
occur early in the UTC day of 21
October. That was a typo. It should have read: 22 October instead. Everywhere else we have
(hopefully) stated 22 October.

Sorry to all for any confusion this caused.

Name: Cary
Date: Sun, 21 Oct 2001 14:11:36 -0600
Subject: Aurora WARNING is now in effect

A middle latitude auroral activity warning is now in effect. The current disturbance has produced
periods of moderate to strong auroral
storm activity. Widespread middle latitude regions may observe periods of activity. We believe
activity may begin to decline a bit as the
IMF swings northward for a while. But it is expected to swing southward again a bit later.
Disturbance #2 should impact within the next
12 hours or so.

Name: max
Date: Sun, 21 Oct 2001 18:13:18 -0600
Subject: aurora ?

Although still 8/8 clouded here in the north of the Netherlands, test pictures suggest that an
unformely red aurora is even observable THROUGH the cloudcover !
Note, THROUGH the clouds !

Around 23.15 UT there were big excursions on my magnetometer. Now, 0.15 UT it is quiet again
but still a somewhat higher level then normal.

Max.

Name: Peter Thomas
Date: Sun, 21 Oct 2001 22:17:06 -0600
Subject: Second wave

Did the second CME hit? There was an abrupt change in the IMF just after 00:00 UTC on 10/22
(just after UTC midnight).

Name: Mike Hardiman
Date: Mon, 22 Oct 2001 00:16:18 -0600
Subject: Next CME arrival?

Well, it is 2:15 EST here. Any thoughts on the next CME arrival? Would like to go to bed, but I'm
thinking of setting my alarm clock for 4am or so to see if the IMF goes southward again, or even
better, the next CME hits before sunrise. Saw a good display here, not the best, since clouds and rain
were around up till 11pm or so, which means we missed the peak up here in NE Vermont.

Good luck to all!

Name: Cary
Date: Mon, 22 Oct 2001 12:12:14 -0600
Subject: Are you all ready for more activity?...

Two major flares from Active Region 9672 have occurred over the last few hours. The first, a
long-duration M6.7/3N flare (spatially
large) occurred at 15:08 UTC. Most recently, this region again erupted with an X1.2 solar flare at
17:59 UTC. These are suspected
proton flares. The major M-class flare was associated with a fairly high velocity inner-coronal shock
wave (indicative of a higher velocity
coronal mass ejection). The X-class flare may have also been associated with a higher velocity CME.
It's too early to tell yet. But in any
case, any CMEs launched by these events should be heavily Earth-directed. No ETA available yet.

Name: Peter, pa1six
Date: Mon, 22 Oct 2001 12:25:26 -0600
Subject: Cary

where is the 2nd CME Cary, did it hide in the tail of the first ??

Gruß Herwig

[Herwig, Rostock]

Hallo,

hat sich voll abgetarnt reingeschlichen.

Aus dem RSGA vom 21.10.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at active to major storm
levels. The full halo CME from the X1/2b flare that occurred at 19/1630 UTC from Region 9661 is
expected to arrive on the middle of day one of the forecast period. III. Event Probabilities 22 Oct-24
Oct Class M 75/75/60 Class X 15/15/10 Proton 15/15/10 PCAF yellow

Aus dem RSGA vom 22.10.

IIA. Geophysical Activity Summary 21/2100Z to 22/2100Z: The geomagnetic field was at minor to
major storm levels. The second CME passage that had been expected today appears to have been
incorporated into the first creating minor to major storm conditions for the entire period aside from a
couple isolated severe storm conditions at high latitudes. The estimated Afr (based on Boulder
magnetometer) reading reached 59 and USAF planetary reached 75. The greater than 10 MeV
proton flux at geosynchronous orbit exceeded threshold at 22/1910 UTC. At the time of issue of this
bulletin the 10 MeV proton flux was at 17 pfu. IIB. Geophysical Activity Forecast: The geomagnetic
field is expected to remain at active to major storm levels through the first part of day one. The field
should return to quiet to active conditions at the end of days one and two. Day three should see
minor to isolated major storm conditions return due a potential CME passage from activity seen in
Region 9672 on 22 October. Protons are expected to remain above 10 MeV through the first day of
period.

Gruß Herwig

[Lutz Schenk]

Vom Speed her und der erwarteten Traveltime, wäre er so jetzt dran.
Aber ich glaube da hat sich vieles vermischt, bzw. ist im allgemeinen Rauschen untergegangen.

Gruß Lutz