Joint USAF/NOAA Report of Solar and Geophysical Activity 29 Mar 2004
Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2004 Mar 29 2210 UTC
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 089 Issued at 2200Z on 29 Mar 2004
IA. Analysis of Solar Active Regions and Activity from 28/2100Z
to 29/2100Z: Solar activity was low. Region 582 (N14E18) produced
several C-class flares today. The largest was a C5/Sf at 1551 UTC.
The region dominates the solar disk in size and complexity and
became more active during the past 24 hours. The region appears to
be growing slowly. The only other region producing flares was 587
(S12E63) which managed to produce two B-class events. All the other
regions on the disk were quiet and stable. A CME was observed by
LASCO off the southwest limb around 0040 UTC, but the lack of
corresponding disk signatures suggests that the source was on the
back side.
IB. Solar Activity Forecast: Solar activity is expected to be
mostly low. There is a chance, however, for an isolated M-class
flare from Region 582 during the next three days (30 March – 1
April).
IIA. Geophysical Activity Summary 28/2100Z to 29/2100Z:
The geomagnetic field was mostly quiet to unsettled, although there
was one active period from 0300-0600 UTC. Solar wind data show a
declining high speed stream with velocities slowly decreasing over
the past 24 hours. The interplanetary magnetic field shows weak
fluctuations in Bz, ranging from -3 nT to +3 nT. The greater than 2
MeV electron flux was high during the past 24 hours.
IIB. Geophysical Activity Forecast: The geomagnetic field is
expected to be unsettled with a slight chance for an active period
during the next 24 hours (30 March). Conditions should decline to
quiet to unsettled for the second and third days (31 March – 1
April) as the solar wind returns to nominal conditions.
III. Event Probabilities 30 Mar-01 Apr
- Class M 35/35/35
- Class X 05/05/05
- Proton 05/05/05
- PCAF green
IV. Penticton 10.7 cm Flux
- Observed 29 Mar 129
- Predicted 30 Mar-01 Apr 130/130/135
- 90 Day Mean 29 Mar 111
V. Geomagnetic A Indices
- Observed Afr/Ap 28 Mar 012/017
- Estimated Afr/Ap 29 Mar 012/013
- Predicted Afr/Ap 30 Mar-01 Apr 012/012-010/008-005/008
VI. Geomagnetic Activity Probabilities 30 Mar-01 Apr
A. Middle Latitudes
- Active 30/25/20
- Minor storm 20/15/10
- Major-severe storm 05/05/05
B. High Latitudes
- Active 30/25/20
- Minor storm 25/20/15
- Major-severe storm 10/05/05
