NOAA SEC Report of Solar-Geophysical Activity 12 Jan 2002

:Product: Report of Solar-Geophysical Activity

:Issued: 2002 Jan 12 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 012 Issued at 2200Z on 12 Jan 2002

IA.  Analysis of Solar Active Regions and Activity from  11/2100Z

to 12/2100Z:  Solar activity has been moderate due to four M-class

events during the past 24 hours. Region 9775 (S05E30) produced three

of these: an M1/Sf at 0322 UTC, an M1/1n at 1519 UTC, and an M1/Sf

at 1929 UTC. The region has not changed size significantly, but

appears to be active due to the emergence of new magnetic flux. The

group currently has a relatively complex magnetic configuration

(beta-gamma). The fourth M-class event was an M3 at 1843 UTC: this

event was associated with erupting prominence activity on the west

limb near S17. Region 9773 (N15W46) continues to be the largest

sunspot group on the disk. This group did not show much change and

managed to produce a few subflares during the past 24 hours.

IB.  Solar Activity Forecast:  Solar activity is expected to be

moderate. Regions 9773, 9775, and 9778 are the most likely sources

for M-class flares. There continues to be a slight chance for a

major flare or proton producing flare from Region 9773.

IIA.  Geophysical Activity Summary 11/2100Z to 12/2100Z:

The geomagnetic field was unsettled to active during the past 24

hours. The enhanced level of activity was due to continued effects

from a coronal hole associated high speed solar wind stream. The

solar wind velocity showed an overall decreasing trend today,

suggesting that the coronal hole effects should not last much

longer. The greater than 10 MeV proton event that began on 10/2045

UTC continues in progress: flux levels decayed throughout the day

and had reached 16.1 PFU at forecast issue time.

IIB.  Geophysical Activity Forecast:  The geomagnetic field is

expected to decrease to mostly unsettled levels for the next two

days as the current enhanced solar wind should subside soon. Quiet

to unsettled levels are expected by day three. LASCO observations do

not show any CMEs to be associated with today’s solar flare

activity.

III.  Event Probabilities 13 Jan-15 Jan

Class M    70/70/70

Class X    20/20/20

Proton     50/20/20

PCAF       in progress

IV.  Penticton 10.7 cm Flux

Observed           12 Jan 233

Predicted   13 Jan-15 Jan  235/240/240

90 Day Mean        12 Jan 224

V.  Geomagnetic A Indices

Observed Afr/Ap 11 Jan  012/021

Estimated Afr/Ap 12 Jan  015/015

Predicted Afr/Ap 13 Jan-15 Jan  012/012-012/010-005/008

VI.  Geomagnetic Activity Probabilities 13 Jan-15 Jan

A.  Middle Latitudes

Active                25/25/20

Minor storm           10/10/05

Major-severe storm    05/05/01

B.  High Latitudes

Active                25/25/20

Minor storm           15/15/10

Major-severe storm    05/05/01