Status Report

NOAA SEC Report of Solar-Geophysical Activity 20 Feb 2002

By SpaceRef Editor
February 20, 2002
Filed under , ,

:Product: Report of Solar-Geophysical Activity
:Issued: 2002 Feb 20 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 051 Issued at 2200Z on 20 Feb 2002
IA. Analysis of Solar Active Regions and Activity from 19/2100Z
to 20/2100Z: Solar activity increased to high levels. Region 9825
(N16W81) produced an impulsive M5/1n flare at 20/0612 UT associated
with Type II and IV radio sweeps and an Earth-directed halo coronal
mass ejection (CME). Region 9825 also produced an impulsive M4 flare
at 20/0251 UT associated with Type II and IV radio sweeps and an
impulsive M4 at 20/0959 UT. This activity appeared to coincide with
the rapid emergence of opposite-polarity flux northwest of the
leader spots, but detailed analysis was hampered by its proximity to
the west limb. Region 9830 (S16W06) remained the largest and most
magnetically complex sunspot group on the disk as multiple magnetic
delta configurations persisted within its leader spots. It produced
an impulsive C9/1n flare at 20/1626 UT associated with minor
discrete radio emission. New Region 9835 (S08W61) produced an
impulsive M3/Sf flare at 20/1711 UT. New Regions 9836 (S02W26) and
9837 (N07E70) were also numbered.
IB. Solar Activity Forecast: Solar activity is expected to be at
moderate to high levels. M-class flares are expected. There is a
chance for isolated major flare activity from Region 9825 (which
will cross the west limb oné‰juFebruary) and Region 9830.
IIA. Geophysical Activity Summary 19/2100Z to 20/2100Z:
Geomagnetic field activity was at quiet to unsettled levels. A brief
greater than 10 MeV proton event at geosynchronous orbit began at
20/0730 UT, reached a maximum of 13.5 PFU at 20/0755 UT, and ended
at 20/0800 UT. This proton event was likely associated with the
M5/1n flare at 20/0612 UT from Region 9825.
IIB. Geophysical Activity Forecast: Geomagnetic field activity is
expected to be at quiet to unsettled levels during 21- 22 February.
Field activity is expected to increase to unsettled to minor storm
levels on 23 February due to an expected CME passage associated with
today’s M5/1n flare. There will be a slight chance for a proton
flare during the period.
III. Event Probabilities 21 Feb-23 Feb
Class M 75/70/70
Class X 10/10/10
Proton 10/10/10
PCAF yellow
IV. Penticton 10.7 cm Flux
Observed 20 Feb 193
Predicted 21 Feb-23 Feb 200/205/205
90 Day Mean 20 Feb 222
V. Geomagnetic A Indices
Observed Afr/Ap 19 Feb 004/004
Estimated Afr/Ap 20 Feb 010/008
Predicted Afr/Ap 21 Feb-23 Feb 007/008-012/015-016/020
VI. Geomagnetic Activity Probabilities 21 Feb-23 Feb
A. Middle Latitudes
Active 15/30/40
Minor storm 05/10/15
Major-severe storm 01/01/05
B. High Latitudes
Active 20/35/40
Minor storm 10/15/20
Major-severe storm 01/05/10

SpaceRef staff editor.