CME von gestern

[lutz schenk]

So wie es aussieht, ist ein "Frontside"-Event doch gut möglich
Mit Radio-Sweep Type 2 und 4, 780 km/s.

(Event liste vom 25. 10. http://sec.noaa.gov/ftpdir/indices/even ... events.txt)

Epam lässt im Moment nichts erkennen, ausser einem leichten Elektronen-Anstieg.

Die GI-Simulation lässt auch die CME-Entwicklung gut erkennen:





Demnach müsste die Front in den frühen UTC-Stunden des 28. erreichen.
Das wäre natürlich vom Timing her nicht so genial für uns.

STD hat auch eine CME-Vorhersage herausgegeben die aber seeeeeeehr vorsichtig ist. http://solar.spacew.com/cme/
Woher die die 1000km/s Lasco-POS-Speed haben wiess ich nicht. In der Lasco-Liste werden nur 789 angegeben.

Die Datenlage scheint wohl recht schwierig.

Na ja, hoffen wir das Beste, lieber Leser

Schönes Wochenende,

Lutz

[Bernhard Dorner]

Hallo Lutz!

Wie schon in der STD-Prognose geschrieben, ist da einiges durcheinandergekommen. Ich persönlich halte den CME von 9:50UT auch für backsided, nicht wie in der LASCO-Mail angegeben von vorne. Da passt das EIT-Movie überhaupt nicht dazu (Irgendwo unter http://www.spacew.com/eit/sunmovie.html). Der Schnürpfel des abfliegende Filaments taucht dann auch wunderbar im C2 auf, aber das wars von der Vorderseite. Zudem gibt es keinerlei Radio-Anzeichen (siehe Event-Liste). Der STD begründet diese Einschätzung ja auch schön.
- Dieser Full-Halo-CME wurde mit 789m/s gemessen (lt. Peters Beitrag) -

Dann folge später um ca 17:50UT der M1.5 mit Sweeps und (vermutlich) CME. Und bei diesem hat man wohl die 1000m/s festgestellt. Leider komme ich im Moment nicht auf die LASCO-Seiten um nachzusehen, was die jetzt eigentlich meinen.

Na dann, allen alles Gute usw.

Sevus
Bernhard

[Bernhard Dorner]

Anschließend der Text, siehe auch http://www.spacew.com/astroalert.html.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

A s t r o A l e r t

Sun-Earth Alert

Solar Terrestrial Dispatch

http://www.spacew.com

Supporting imagery

http://www.spacew.com/astroalert.html

26 October 2002

(Friendly Reminder: Turn your Clocks Back One Hour Tonight!)

Some unusually intense solar coronal mass ejection (CME) activity has
been observed over the last 48 hours. Almost all of it has been directed away
from the Earth, but one coronal mass ejection in particular has the potential
of producing at least a mild Earth-bound impact. This event originated from
sunspot complex 10162 (the same sunspot complex that was visible to the
unaided eye several days ago) near 18:00 UTC (2 pm EDT) on 25 October.

The problem with this particular event is that there is substantial
uncertainty whether this CME contained an Earthward-directed component. Most
of the mass ejected from this event was hurled well north of the Earth at
high velocity (near 1,000 kilometers per second) and has no chance of
reaching the Earth. However, there are hints in the available data that a
minor component of this CME may have contained a trajectory that could bring
a portion of it toward the Earth. If this is true, the Earth may observe an
impact from the flanking portion of this CME sometime late on 27 October or
on 28 October UTC time. For those living in eastern North America, this UTC
time translates roughly to the late afternoon/evening hours of 27 October or
morning hours of 28 October EST. If this impact occurs, middle latitude
observers may observe an intensification of auroral activity ("northern
lights") during the evening and/or early morning hours of 27/28 October EST.

Another very impressive solar coronal event also occurred today in the
form of two impressively large prominence eruptions on the southeastern
solar limb in the hours prior to 08:00 UTC (4 am EDT) on 25 October. A movie
of this event is currently available at (~3 megabytes):

http://sohowww.nascom.nasa.gov/data/LAT ... it_304.mpg

for roughly the next 24 hours. A smaller 6-frame GIF image animation (681
kilobytes) of this activity is available at:

http://www.spacew.com/astroalert.html

This eruption was also thought (by the LASCO science team) to be associated
with a fairly high velocity (789 km/sec) full halo (strongly
Earthward-directed) coronal mass ejection. However, our own analysis has
revealed convincing evidence that suggests this full halo CME may in fact be
a back-sided event. If so, this CME would be directed away from the Earth (on
the other side of the Sun) and would not produce an Earth-bound impact.

A CME Impact Prediction has been issued and is available at:
http://www.spacew.com/cme. It contains details concerning the recent
activity.

There is a chance a Middle Latitude Auroral Activity Watch may be issued
for the UTC day of 28 October (evening/early-morning hours of 27/28 October
EST). If a watch is released, it will be immediately available at:
www.spacew.com. For those who want immediate delivery of watches and
warnings, visit: http://www.spacew.com/www/sublists.html and subscribe.

** End of the AstroAlert Bulletin **