NOAA SEC Report of Solar-Geophysical Activity 23 Nov 2001
:Product: Report of Solar-Geophysical Activity :Issued: 2001 Nov 23 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 327 Issued at 2200Z on 23 Nov 2001 IA. Analysis of Solar Active Regions and Activity from 22/2100Z to 23/2100Z: Solar activity reached high levels. Following yesterday's M3/2B flare from Region 9698 (S24W82), a major flare event occurred in Region 9704 (S17W51). This M9/2n long duration event peaked at 22/2330 UTC, and was associated with a 9700 sfu tenflare, type-II and type-IV radio sweeps, and several erupting filaments in the vicinity of the flare site. A subsequent full halo CME was observed in SOHO/LASCO imagery, and energetic proton flux levels were also significantly enhanced by this event, adding to the above-threshold fluxes already caused by the prior flare. Most other activity for the remainder of the period was limited to weak C-class flares. New Region 9715 (N07E80) was numbered as it rotated into view on the east limb. IB. Solar Activity Forecast: Solar activity is expected to be predominantly low to moderate for the next three days. Region 9704 remains a potential source for an isolated major flare. IIA. Geophysical Activity Summary 22/2100Z to 23/2100Z: The geomagnetic field was predominantly quiet to unsettled. A single active period was observed at Boulder during 23/1200-1500 UTC. Energetic proton flux at geosynchronous orbit was on the rise at the beginning of the period, and achieved event thresholds for 100 MeV integral flux above 1 pfu at 22/2250 UTC, and 10 MeV integral flux above 10 pfu at 22/2320 UTC. Both events remain in progress, with maximum 100 MeV integral flux of 4 pfu observed at 23/0850 UTC, and maximum 10 MeV integral flux of 4800 pfu at 23/1400 UTC. IIB. Geophysical Activity Forecast: Geomagnetic field activity is expected to increase to active levels within 24 hours, and remain at predominantly active levels for the next three days. Isolated minor and major storm periods are possible. These increases are expected in response to the various CME episodes of the last three days. The energetic proton events are expected to persist,. The 100 MeV integral flux levels are expected to drop below threshold within 24 hours, while the 10 MeV integral flux levels are expected to remain above threshold for at least 48 hours. III. Event Probabilities 24 Nov-26 Nov Class M 40/40/40 Class X 10/10/10 Proton 99/95/75 PCAF in progress IV. Penticton 10.7 cm Flux Observed 23 Nov 177 Predicted 24 Nov-26 Nov 175/170/170 90 Day Mean 23 Nov 218 V. Geomagnetic A Indices Observed Afr/Ap 22 Nov 008/008 Estimated Afr/Ap 23 Nov 012/010 Predicted Afr/Ap 24 Nov-26 Nov 020/020-040/050-030/030 VI. Geomagnetic Activity Probabilities 24 Nov-26 Nov A. Middle Latitudes Active 30/35/35 Minor storm 15/25/20 Major-severe storm 05/10/05 B. High Latitudes Active 35/45/35 Minor storm 15/30/25 Major-severe storm 10/15/10
