Viewing archive of Wednesday, 7 September 2011
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 2011 Sep 07 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 250 Issued at 2200Z on 07 Sep 2011IA. Analysis of Solar Active Regions and Activity from 06-2100Z to 07-2100Z Solar activity was high. Region 1283 (N14W32) produced
another major flare, an X2/2b at 06/2220Z. The X2 flare was
associated with Types II and IV radio sweeps, a 740 sfu Tenflare and
an Earth-directed halo CME. The CME had an estimated speed of around
800 km/s, based on STEREO-A COR2 images, with the bulk of mass
directed north of the ecliptic plane. Region 1283 maintained a weak
magnetic delta in the north-central portion of the group and was
classified as a Dai-type with a beta-gamma-delta magnetic
configuration. No new regions were numbered.
IB. Solar Activity Forecast
Solar activity is expected to be
moderate during the period (08 - 10 September) with a chance for
another X-class flare from Region 1283.
IIA. Geophysical Activity Summary 06-2100Z to 07-2100Z
Geomagnetic field activity was at mostly quiet levels. A proton flux
enhancement at greater than 100 MeV and greater than 10 MeV began
around 06/2300Z at geosynchronous orbit in the wake of the X2 flare
mentioned above. The greater than 2 MeV electron flux at
geosynchronous orbit reached high levels during the period.
IIB. Geophysical Activity Forecast
Geomagnetic activity is
expected to be at mostly quiet levels on day 1 (08 September). An
increase to unsettled levels, with a chance for active levels, is
expected late on day 2 (09 September) due to a CME arrival. A
further increase to unsettled to active levels, with a chance for
minor storm levels, is expected on day 3 (10 September) as the CME
passage continues. There will be a chance for a greater than 10 MeV
proton event at geosynchronous orbit during the period.
III. Event Probabilities 08 Sep to 10 Sep
| Class M | 75% | 75% | 75% |
| Class X | 30% | 30% | 30% |
| Proton | 30% | 30% | 30% |
| PCAF | Green | ||
IV. Penticton 10.7 cm Flux
Observed 07 Sep 113 Predicted 08 Sep-10 Sep 110/105/100 90 Day Mean 07 Sep 098
V. Geomagnetic A Indices
Observed Afr/Ap 06 Sep 005/007 Estimated Afr/Ap 07 Sep 005/005 Predicted Afr/Ap 08 Sep-10 Sep 005/005-010/005-020/018
VI. Geomagnetic Activity Probabilities 08 Sep to 10 Sep
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 25% | 30% |
| Minor storm | 01% | 10% | 25% |
| Major-severe storm | 01% | 01% | 05% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 30% | 40% |
| Minor storm | 01% | 15% | 30% |
| Major-severe storm | 01% | 01% | 10% |
All times in UTC
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