Status Report

NOAA SEC Report of Solar-Geophysical Activity 23 Nov 2001

By SpaceRef Editor
November 23, 2001
Filed under , ,
:Product: Report of Solar-Geophysical Activity
:Issued: 2001 Nov 23 2200 UT
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
#Space Environment Center and the U.S. Air Force.
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 327 Issued at 2200Z on 23 Nov 2001
IA.  Analysis of Solar Active Regions and Activity from  22/2100Z
to 23/2100Z:  Solar activity reached high levels.  Following
yesterday's M3/2B flare from Region 9698 (S24W82), a major flare
event occurred in Region 9704 (S17W51).  This M9/2n long duration
event peaked at 22/2330 UTC, and was associated with a 9700 sfu
tenflare, type-II and type-IV radio sweeps, and several erupting
filaments in the vicinity of the flare site.  A subsequent full halo
CME was observed in SOHO/LASCO imagery, and energetic proton flux
levels were also significantly enhanced by this event, adding to the
above-threshold fluxes already caused by the prior flare.  Most
other activity for the remainder of the period was limited to weak
C-class flares.  New Region 9715 (N07E80) was numbered as it rotated
into view on the east limb.
IB.  Solar Activity Forecast:  Solar activity is expected to be
predominantly low to moderate for the next three days.  Region 9704
remains a potential source for an isolated major flare.
IIA.  Geophysical Activity Summary 22/2100Z to 23/2100Z:
The geomagnetic field was predominantly quiet to unsettled.  A single
active period was observed at Boulder during 23/1200-1500 UTC. 
Energetic proton flux at geosynchronous orbit was on the rise at the
beginning of the period, and achieved event thresholds for 100 MeV
integral flux above 1 pfu at 22/2250 UTC, and 10 MeV integral flux
above 10 pfu at 22/2320 UTC.  Both events remain in progress, with
maximum 100 MeV integral flux of 4 pfu observed at 23/0850 UTC, and
maximum 10 MeV integral flux of 4800 pfu at 23/1400 UTC.
IIB.  Geophysical Activity Forecast:  Geomagnetic field activity is
expected to increase to active levels within 24 hours, and remain at
predominantly active levels for the next three days.  Isolated minor
and major storm periods are possible.  These increases are expected
in response to the various CME episodes of the last three days.  The
energetic proton events are expected to persist,.  The 100 MeV
integral flux levels are expected to drop below threshold within 24
hours, while the 10 MeV integral flux levels are expected to remain
above threshold for at least 48 hours.
III.  Event Probabilities 24 Nov-26 Nov
Class M    40/40/40
Class X    10/10/10
Proton     99/95/75
PCAF       in progress
IV.  Penticton 10.7 cm Flux
Observed           23 Nov 177
Predicted   24 Nov-26 Nov  175/170/170
90 Day Mean        23 Nov 218
V.  Geomagnetic A Indices
Observed Afr/Ap 22 Nov  008/008
Estimated Afr/Ap 23 Nov  012/010
Predicted Afr/Ap 24 Nov-26 Nov  020/020-040/050-030/030
VI.  Geomagnetic Activity Probabilities 24 Nov-26 Nov
A.  Middle Latitudes
Active                30/35/35
Minor storm           15/25/20
Major-severe storm    05/10/05
B.  High Latitudes
Active                35/45/35
Minor storm           15/30/25
Major-severe storm    10/15/10

SpaceRef staff editor.