Status Report

NOAA SEC Report of Solar-Geophysical Activity 27 Mar 2001

By SpaceRef Editor
March 27, 2001
Filed under ,
:Product: Report of Solar-Geophysical Activity
:Issued: 2001 Mar 27 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 086 Issued at 2200Z on 27 Mar 2001
IA.  Analysis of Solar Active Regions and Activity from  26/2100Z
to 27/2100Z:  Solar activity was moderate.  Region 9401 (N22E30)
produced an impulsive M2/1N event at 27/1630Z.  This event had an
associated Type II radio sweep with a speed of 500 km/s.  Region
9393 (N17E11) grew significantly in area overnight and maintains a
complex beta-gamma-delta magnetic configuration; however, the region
has only produced C-class X-ray events during the period.  Several
other C-class events occurred from Regions 9390 (N14W22), and 9402
(N14W11).  New Region 9404 (S06E66) was numbered today.
IB.  Solar Activity Forecast:  Solar activity is expected to be
moderate to high.  Region 9393 has the best potential to produce a
major flare.
IIA.  Geophysical Activity Summary 26/2100Z to 27/2100Z:
The geomagnetic field was mostly quiet to active.  Two different
shocks were observed on the ACE spacecraft.  The first shock
occurred at 27/0108Z with an associated sudden impulse of 27 nT on
the Boulder magnetometer at 27/0145Z.  This activity was believed to
be associated with the CME back on 24 March.  The second shock
occurred at 27/1718Z with an associated sudden impulse of 10 nT
observed on the Boulder magnetometer at 27/1745Z.  The second shock
was believed to be associated with the halo CME on 25 March.  The
greater than 10 MeV proton flux at geosynchonous orbit was enhanced
during the period, but stayed below event threshold with an observed
maximum of approximately 6 pfu.
IIB.  Geophysical Activity Forecast:  The geomagnetic field is
expected to be predominately unsettled to minor storm conditions
with isolated major storm conditions possible during the first day
of the period.  This possible increase in activity is due to the
faint full halo CME seen in LASCO/SOHO imagery on 25 March at
approximately 1700Z.  The geomagnetic field is expected to return to
predominately quiet to unsettled conditions the rest of the period
with isolated active conditions possible.
III.  Event Probabilities 28 Mar-30 Mar
Class M    75/75/75
Class X    20/20/20
Proton     15/15/15
PCAF       green
IV.  Penticton 10.7 cm Flux
Observed           27 Mar 273
Predicted   28 Mar-30 Mar  235/240/240
90 Day Mean        27 Mar 161
V.  Geomagnetic A Indices
Observed Afr/Ap 26 Mar  002/006
Estimated Afr/Ap 27 Mar  015/015
Predicted Afr/Ap 28 Mar-30 Mar  020/025-015/015-008/010
VI.  Geomagnetic Activity Probabilities 28 Mar-30 Mar
A.  Middle Latitudes
Active                40/30/25
Minor storm           30/20/10
Major-severe storm    10/05/01
B.  High Latitudes
Active                30/40/30
Minor storm           40/25/15
Major-severe storm    20/10/05

SpaceRef staff editor.