Viewing archive of Sunday, 30 September 2001
Solar activity report
Any mentioned solar flare in this report has a scaling factor applied by the Space Weather Prediction Center (SWPC). Because of the SWPC scaling factor, solar flares are reported as 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.
Report of Solar-Geophysical Activity 2001 Sep 30 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.comJoint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 273 Issued at 2200Z on 30 Sep 2001
IA. Analysis of Solar Active Regions and Activity from 29-2100Z to 30-2100Z
Solar activity remained at moderate levels. Region 9628
(S17W76) produced a long-duration M1/Sf flare at 30/1141 UTC
associated with minor discrete frequency radio emission. Region 9628
may have decayed a bit as it approached the west limb, but remained
large and complex. Decay was also noted in Region 9632 (S18W61) as
its large interior spot mass began to split, which may have
dissipated the magnetic delta structure contained therein.
Nonetheless, this region remained large and complex. Region 9636
(N14W15), a reverse-polarity sunspot group, showed gradual
development during the day. It was moderate in size and complexity
as it produced isolated subflares, none of which were associated
with significant X-ray or radio emission.
IB. Solar Activity Forecast
Solar activity is expected to remain
at moderate levels. Isolated M-class flares will be possible from
Regions 9628, 9632, and 9636. Regions 9628 and 9632 each could
produce an isolated major flare before they rotate out of view on 01
and 02 October, respectively.
IIA. Geophysical Activity Summary 29-2100Z to 30-2100Z
Geomagnetic field activity ranged from quiet to minor storm levels.
Minor storm levels occurred globally during 29/2100 - 2400 UTC
following a sustained period of southward IMF Bz (as measured by
NASA's ACE spacecraft). Activity decreased to quiet to unsettled
levels during 30/0000 - 1500 UTC, then increased to active levels
for the rest of the period. An interplanetary shock passed the ACE
spacecraft at 30/1848 UTC. The source for this shock may have been a
CME that followed a long-duration M3/2n flare from Region 9636 at
28/0830 UTC. The greater than 10 MeV event that began at 24/1215 UTC
ended at 30/1710 UTC.
IIB. Geophysical Activity Forecast
Active geomagnetic conditions
will be possible during 01 - 02 October due to recent CME activity.
Field activity is expected to decrease to quiet to unsettled levels
on 03 October. There will be a slight chance for a proton flare from
Region 9628 or 9632 during the period.
III. Event Probabilities 01 Oct to 03 Oct
Class M | 80% | 75% | 70% |
Class X | 25% | 20% | 10% |
Proton | 20% | 15% | 10% |
PCAF | yellow
|
IV. Penticton 10.7 cm Flux
Observed 30 Sep 236
Predicted 01 Oct-03 Oct 230/225/225
90 Day Mean 30 Sep 176
V. Geomagnetic A Indices
Observed Afr/Ap 29 Sep 019/021
Estimated Afr/Ap 30 Sep 012/012
Predicted Afr/Ap 01 Oct-03 Oct 020/015-015/012-012/012
VI. Geomagnetic Activity Probabilities 01 Oct to 03 Oct
A. Middle Latitudes |
Active | 40% | 40% | 30% |
Minor storm | 20% | 20% | 10% |
Major-severe storm | 10% | 10% | 01% |
B. High Latitudes |
Active | 50% | 50% | 35% |
Minor storm | 25% | 25% | 15% |
Major-severe storm | 15% | 15% | 01% |
All times in UTC
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