Joint USAF/NOAA Report of Solar and Geophysical Activity 10 Sep 2005

Prepared jointly by the U.S. Dept. of Commerce, NOAA,
Space Environment Center and the U.S. Air Force.
Updated 2005 Sep 10 2204 UTC

Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 253 Issued at 2200Z on 10 Sep 2005

IA. Analysis of Solar Active Regions and Activity from 09/2100Z to 10/2100Z: Solar activity was at high levels. Region 808 (S09E44) produced an impulsive X1 major flare at 10/1643Z with an associated Tenflare of 600 sfu. Further significant activity included an M4/1n at 10/1936Z, an M3/1f at 10/0614Z, and an M1 at 10/0907Z. This region continues to exhibit an extremely complex and compact spot group with 1400 millionths of area visible in white light. Magnetic analysis continues to depict a very strong beta-gamma-delta configuration in the dominant central penumbral spot. Region 809 (N10E34) was quiescent during the period. No new regions were numbered today.

IB. Solar Activity Forecast: Solar activity is expected to be at high levels. Region 808 is expected to continue to produce major flares.

IIA. Geophysical Activity Summary 09/2100Z to 10/2100Z: The geomagnetic field ranged from quiet to minor storm levels. Southward Bz and continued transient flow are responsible for the elevated conditions. The greater than 10 MeV proton event that began on 08/0215Z reached a peak flux of 1040 pfu at 10/1105Z. The greater than 100 MeV proton event that began at 08/0405Z reached a peak flux of 7 pfu at 09/1920Z.

IIB. Geophysical Activity Forecast: The geomagnetic field is expected to be at unsettled to minor storm levels. Isolated major storm conditions may be possible on 11 September due to the full halo CME observed on 09 September, which was related to the X6/2b major flare. Isolated minor storm conditions are expected to continue on 12-13 September due to ongoing transient flow and a recurrent coronal hole. The greater than 10 MeV proton event is expected to continue through the next three days. The greater than 100 MeV proton event is expected to end late on 11 September. Further major flare activity could prolong the proton events.

III. Event Probabilities 11 Sep-13 Sep

• Class M 90/90/90
• Class X 75/75/75
• Proton 99/99/99
• PCAF in progress

IV. Penticton 10.7 cm Flux

• Observed 10 Sep 100
• Predicted 11 Sep-13 Sep 100/105/105
• 90 Day Mean 10 Sep 091

V. Geomagnetic A Indices

• Observed Afr/Ap 09 Sep 012/017
• Estimated Afr/Ap 10 Sep 016/020
• Predicted Afr/Ap 11 Sep-13 Sep 020/030-015/020-015/020

VI. Geomagnetic Activity Probabilities 11 Sep-13 Sep

A. Middle Latitudes

• Active 40/35/35
• Minor storm 25/15/15
• Major-severe storm 15/10/10

B. High Latitudes

• Active 45/40/40
• Minor storm 30/25/25
• Major-severe storm 20/15/15