Viewing archive of Saturday, 7 September 2002

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 2002 Sep 07 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 250 Issued at 2200Z on 07 Sep 2002

IA. Analysis of Solar Active Regions and Activity from 06-2100Z to 07-2100Z

Solar activity was low. Only a few C-class flares occurred. New Region 105 (S06E77) is currently rotating around the east limb and appears to be the return of old active Region 69 (S08, L=299). So far the area has not produced significant activity. New Region 104 (N11E59) was also numbered.
IB. Solar Activity Forecast
Solar activity is expected to be low to moderate. Region 105 is the most likely source of energetic flares.
IIA. Geophysical Activity Summary 06-2100Z to 07-2100Z
The geomagnetic field ranged from quiet to severe storm levels. A shock in the solar wind was observed by the NASA ACE spacecraft at 07/1609 UTC and was followed by a 7 nT sudden impulse on the Boulder magnetometer at 07/1638 UTC. This shock is believed to be related to the eruptive filament and CME which occurred on 05 September. The greater than 10 MeV proton flux crossed the 10 pfu event threshold at 07/0440 UTC after a slow rise over the previous 28 hours. Peak event flux so far was 208 pfu at 07/1650 UTC. Retrospect analysis suggests that these particles are most likely associated with the eruptive filament mentioned above rather than a west limb event as suggested yesterday.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be at active to storm levels over the next 24 hours, becoming quiet to unsettled by 10 September. The greater than 10 MeV proton event is expected to end by 09 September.
III. Event Probabilities 08 Sep to 10 Sep
Class M50%50%50%
Class X05%05%05%
PCAFin progress
IV. Penticton 10.7 cm Flux
  Observed       07 Sep 183
  Predicted   08 Sep-10 Sep  190/200/210
  90 Day Mean        07 Sep 170
V. Geomagnetic A Indices
  Observed Afr/Ap 06 Sep  006/010
  Estimated     Afr/Ap 07 Sep  030/055
  Predicted    Afr/Ap 08 Sep-10 Sep  020/025-010/015-008/010
VI. Geomagnetic Activity Probabilities 08 Sep to 10 Sep
A. Middle Latitudes
Minor storm20%15%15%
Major-severe storm15%05%05%
B. High Latitudes
Minor storm25%20%20%
Major-severe storm15%05%05%

All times in UTC

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