Vorsichtiger Watch für (13.04.2006)

[Lutz Schenk]

Hallo Zusammen,

auf Grund der derzeitigen ACE-Werte könnte es bei Umschlagen des Bz nach Süd mal wieder Aktivität geben.

Die aktuelle Signatur sieht eigentlich eher nach einem verwaschenen CME aus. Die Dichte ging gleichzeitig und gleichartig mit dem Speed seit 4 UT und nochmals ab 9 UT in die höhe. Solch gleichartiger Verlauf ist für einen coronal stream eher nicht typisch. Was es nun genau ist, bleibt mir jedenfalls unklar.

Vorgestern gab es eine partial Halo CME Mail, die aber eher sehr dürftig klang. Daher hatte ich sie auch gar nicht erst gepostet.

Aber vielleicht ist da ja doch ein bissel was vom Westrand her durchgekommen.

Hier die Mail:

UCMEO 93001 50514 1205/
50513 61722 82312 0001/ 360// 123// 11645
50513 61613 81728 11112 10759 1112/
99999

PLAIN

BT


LASCO/EIT observed a nice and bright full halo event on 2005/05/13. The
event was first seen in C2 at 17:22 UT already half way to the end of the
C2 FOV and completely surrounding the C2 occulting. The event looks
brighter all above the NE Limb. Unfortunately, the LASCO Electronic
Box (LEB) failed afterward, and therefore there are no more C2 images
until 23:22 UT. For the same reason, there is a C3 data gap between
17:50 and 22:50 UT, and an EIT 195 data gap between 17:37 and 22:57 UT.
The event was first seen in C3 at 17:42 UT already as a very symmetric
and bright halo. Next C3 frame available was taken at 23:12 UT. By
that time, the halo event is no longer visible in the C3 FOV. A rough
estimation of the mean plane-of-sky speed (rough because it was determined
with the only 2 frames where the halo was seen) is as follows (LE defined
as the position where the intensity gradient is maximum):

PA 000: ~ 794 km/sec
PA 090: ~ 1020 km/sec
PA 180: ~ 927 km/sec
PA 270: ~ 915 km/sec

A diffuse front can be seen over the North and South Poles ahead of the
main structure of the event. If the LE is considered as the outermost
part of this diffuse front, the mean plane-of sky speed is:

PA 000: 1645 km/sec
PA 180: 1640 km/sec

GOES reported a long duration M8.0 X-ray flare on NOAA AR 10759 (N12E11)
between 16:13 - 17:28 UT with peak emission at 16:57 UT. Associated proton
event. The >10 MeV proton flux exceeded the event threshold around
06:00 UT this morning. EIT 195 images show a strong brightening that
starts to develop by 16:37 UT. A dimming region develops to SW and NE
of the AR. Also a an important and symmetric EIT wave with epicenter
on the AR develops.

In summary, the event has therefore been determined as a fast and strong
Full Halo CME, frontsided, associated with a LDE M-class X-ray event on
NOAA AR 10759.

- Movies of the event will shortly be made available at:

ftp://ares.nrl.navy.mil/pub/lasco/halo/20050513

(I'm still actually abroad and experiencing technical difficulties to make
the gif images. They will be ready for sure next week. I do apology for
that).

NOTE:
I'll be flying back on Sunday. Therefore, if something happens, I'll not
be able to deliver the corresponding alerts until Monday.

Best wishes,
Guillermo Stenborg


+--------------------------------------------------+
Dr. Guillermo A. Stenborg
SOHO-LASCO Operations Scientist,
CUA, MC 612.5, Bldg 26, Rm 001, F: +1-301-286-0264
NASA Goddard Space Flight Center,
Greenbelt, MD 20771. P: +1-301-286-2941

e-mail: stenborg@kreutz.nascom.nasa.gov
+--------------------------------------------------+

Weiterhin besteht ein Watch des STD:

Updated: 16:30 UTC 13 April (12:30 pm EDT, 13 April)

Geomagnetic and Auroral Activity Update

Geomagnetic and auroral activity will intensify during the next 72 hours due to effects of another coronal hole based disturbance. Periods of active to minor storm conditions are possible during the next 24 hours. On 14 and 15 April, there is a chance for brief major storm conditions. An aurora watch is being issued through 16 April.

Solar Activity Update

Solar activity is expected to remain relatively quiet.

Quelle:

http://www.spacew.com/

Vielleicht überlagern sich da auch Effekte.

Infos zum aktuellen coronal hole siehe hier :
http://www.dxlc.com/solar/

Viele Grüße,

Lutz

[Ulrich Rieth]

Hallo!

Hier der Vollständigkeit halber der STD Watch.
Er bezieht sich ausschließlich auf das Coronal Hole und nach der jetzigen ACE Signatur scheint es sich auch nur noch um ein solches zu handeln, evtl. noch gemixt mit CME Resten, aber unsicher.
Gruß

Ulrich

---------

MIDDLE LATITUDE AURORAL ACTIVITY WATCH
Issued: 16:35 UTC, 13 April 2006
Solar Terrestrial Dispatch
www.spacew.com


VALID BEGINNING AT: EFFECTIVE IMMEDIATELY
VALID UNTIL: 23:00 UTC (7 pm EDT) ON 16 April

PREDICTED IMPACT TIME OF DISTURBANCE: INITIAL LEADING EDGE IS ARRIVING

HIGH RISK PERIOD: 13 - 15 APRIL
MODERATE RISK PERIOD: 13 - 16 APRIL

PREDICTED ACTIVITY INDICES: 24, 30, 25, 17 (13 - 16 APRIL)

POTENTIAL MAGNITUDE OF MIDDLE LATITUDE AURORAL ACTIVITY: LOW - MODERATE

POTENTIAL DURATION OF THIS ACTIVITY: MAIN BELT = 24 TO 48 HOURS
MINOR BELT = 48 TO 72 HOURS

ESTIMATED OPTIMUM OBSERVING CONDITIONS: NEAR LOCAL MIDNIGHT

EXPECTED LUNAR INTERFERENCE: HIGH

OVERALL OPPORTUNITY FOR OBSERVATIONS FROM MIDDLE LATITUDES: POOR TO FAIR

AURORAL ACTIVITY *MAY* BE OBSERVED APPROXIMATELY NORTH OF A LINE FROM...

SOUTHERN BRITISH COLUMBIA TO EXTREME NORTHERN IDAHO TO NORTHERN MONTANA
TO NORTH DAKOTA TO DARK-SKY SITES OF MINNESOTA TO NORTHERN WISCONSIN TO
NORTHERN MICHIGAN TO NORTHERN NEW YORK STATE TO MAINE.

ACTIVITY *MAY* ALSO BE OBSERVED APPROXIMATELY NORTH OF A LINE FROM...

EXTREME NORTHERN SCOTLAND TO FINLAND TO SWEDEN TO NORTHERN RUSSIA.

ACTIVITY *MAY* ALSO BE OBSERVED APPROXIMATELY SOUTH OF A LINE FROM...

EXTREME SOUTHERN NEW ZEALAND.


SYNOPSIS...

Another coronal hole based disturbance is in the process of arriving. It
is expected to yield several days of enhanced auroral activity - mostly
within the higher latitude regions north of the U.S. / Canada border, but
with periods of substorm activity that should become visible over the more
mid-latitude regions as well. The near-full phase of the moon will
substantially inhibit observations, particularly of activity near the
horizon. As a result, this disturbance is not expected to produce
particularly impressive activity. However, some localized substorms could be
fairly strong.

This watch will remain valid through 23:00 UTC (7 pm EDT) on 16
April. It will then be updated or allowed to expire. For updated
information, visit: http://www.spacew.com/aurora/forum.html. For real-time
plots of current activity, visit: http://www.spacew.com/plots.html or
www.sec.noaa.gov.

PLEASE REPORT OBSERVATIONS OF AURORAL ACTIVITY TO:
http://www.spacew.com/submitsighting.html


** End of Watch **

[RainerKracht]

Hallo,

die Mintron steht auf dem Fensterbrett und sieht zur Zeit nur Wolken.
In etwa einer Stunde könnte es hier aber aufklaren.
Wenn sich Bz dann noch in den Keller bemüht...

Grüße, Rainer

[Lutz Schenk]

Guten Morgen,

na das war ja wieder mal ein obergeniales Timing.

Viele Grüße,

Lutz

[Christian Fenn]

Es ist zum Verzweifeln. Bei mir ist draußen bedeckt und zuviel Licht. Und bei euch?

[Lutz Schenk]

Ja, hier derzeit auch zuviel Lichtveschmutzung
Auch nur minimale Wolkenlücken...

Zum Abend könnte es etwas aufklaren. Aber ich glaub nicht wirklich das es bis dahin hält.

LG Lutz