Viewing archive of Thursday, 8 September 2005
Solar activity report
Any mentioned solar flare in this report has a scaling factor applied by the Space Weather Prediction Center (SWPC). Because of the SWPC scaling factor, solar flares are reported as 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.
Report of Solar-Geophysical Activity 2005 Sep 08 2204 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.comJoint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 251 Issued at 2200Z on 08 Sep 2005
IA. Analysis of Solar Active Regions and Activity from 07-2100Z to 08-2100Z
Solar activity remains at high levels. An X5/2b flare
was in progress from Region 808 (S09E67) at the time of this
writing. Moderate centimetric radio bursts are also in progress,
including a 990 sfu Tenflare. Very active Region 808 is rotating
into view as a large and complex sunspot cluster. Limb proximity is
still hindering the analysis, but this compact spot group will
likely exceed 1000 millionths of white light area. Numerous C-class
flares and two M2 flares preceded the X5 event. New Region 809
(N10E60) was numbered today.
IB. Solar Activity Forecast
Solar activity is expected to remain
at high levels. Region 808 is a large and complex sunspot group
capable of producing M and X-class flares.
IIA. Geophysical Activity Summary 07-2100Z to 08-2100Z
The geomagnetic field was quiet to unsettled. A sudden disturbance of
41 nT (magnetic crochet) was observed in the geomagnetic field
following today's X5 flare. A greater than 10 and greater than 100
MeV proton event occurred following yesterday's X17 flare on the
southeast limb. The greater than 10 MeV proton event began at
08/0215Z and remains in progress. The peak flux so far was 87 pfu at
08/1950Z. The greater than 100 MeV proton event began at 08/0405Z
and also remains in progress. The peak flux was 7 pfu at 08/1925Z.
A greater than 100 MeV proton event from a source on the east
limb is extremely rare. The greater than 2 MeV electron flux at
geosynchronous orbit was at high levels again today.
IIB. Geophysical Activity Forecast
The geomagnetic field is
expected to range from quiet to minor storm levels. The CME
associated with yesterday's X17 flare was very large and very fast.
Although the magnetic cloud associated with this CME is not expected
to impact Earth, a shock passage is expected, which will likely
produce active to minor storm periods on 09 Sep. Isolated active
periods are expected on 10 and 11 Sep. The greater than 10 MeV
proton event currently in progress is expected to continue through
10 Sep. A further enhancement in the greater than 10 MeV protons
will likely follow the anticipated shock passage on 09 Sep. Today's
X5 flare may enhance the existing proton event. The greater than 100
MeV proton event will persist through 09 Sep.
III. Event Probabilities 09 Sep to 11 Sep
Class M | 80% | 80% | 80% |
Class X | 50% | 50% | 50% |
Proton | 99% | 90% | 75% |
PCAF | in progress
|
IV. Penticton 10.7 cm Flux
Observed 08 Sep 094
Predicted 09 Sep-11 Sep 100/110/110
90 Day Mean 08 Sep 091
V. Geomagnetic A Indices
Observed Afr/Ap 07 Sep 018/015
Estimated Afr/Ap 08 Sep 008/012
Predicted Afr/Ap 09 Sep-11 Sep 020/025-015/020-008/010
VI. Geomagnetic Activity Probabilities 09 Sep to 11 Sep
A. Middle Latitudes |
Active | 40% | 30% | 25% |
Minor storm | 20% | 15% | 10% |
Major-severe storm | 10% | 05% | 01% |
B. High Latitudes |
Active | 50% | 40% | 30% |
Minor storm | 30% | 20% | 15% |
Major-severe storm | 15% | 10% | 05% |
All times in UTC
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