NOAA SEC Report of Solar-Geophysical Activity 22 Oct 2001
:Product: Report of Solar-Geophysical Activity
:Issued: 2001 Oct 22 2210 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 295 Issued at 2200Z on 22 Oct 2001
IA. Analysis of Solar Active Regions and Activity from 21/2100Z
to 22/2100Z: Solar activity was at high levels. Region 9672
(S18E13) produced an X1/2b flare at 22/1759 UTC and an associated
Type II radio sweep with a shock velocity estimated at 1043 km/s.
More than 20 twenty percent umbral coverage of large asymmetrical
spot was observed in H-alpha. Shortly before this flare, Region
9672 had produced an M6/2n at 22/1508 UTC which had also produced a
Type II and IV radio sweep (shock velocity estimated at 955 km/sec).
Region 9672 had formed a strong delta configuration earlier in
period. LASCO/EIT imagery has not updated sufficiently, to be able
to ascertain, if a CME was created from either of these flares.
Region 9658 (rotated of west limb at S15) produced an M1/Sf at
22/0040 UTC before exiting the visible disk. New Region 9677 (N20E48)
was numbered today.
IB. Solar Activity Forecast: Solar activity is expected to be at
moderate to high levels. Region 9672 remains capable of
producing further M-class or isolated major flares.
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.
III. Event Probabilities 23 Oct-25 Oct
Class M 80/80/75
Class X 40/40/30
IV. Penticton 10.7 cm Flux
Observed 22 Oct 233
Predicted 23 Oct-25 Oct 230/220/220
90 Day Mean 22 Oct 192
V. Geomagnetic A Indices
Observed Afr/Ap 21 Oct 029/040
Estimated Afr/Ap 22 Oct 045/075
Predicted Afr/Ap 23 Oct-25 Oct 015/030-015/015-020/030
VI. Geomagnetic Activity Probabilities 23 Oct-25 Oct
A. Middle Latitudes
Minor storm 20/15/30
Major-severe storm 01/05/10
B. High Latitudes
Minor storm 30/20/40
Major-severe storm 10/05/15