Viewing archive of Thursday, 11 April 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 Apr 11 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 101 Issued at 2200Z on 11 Apr 2002

IA. Analysis of Solar Active Regions and Activity from 10-2100Z to 11-2100Z

Solar activity was at low levels. Region 9893 (N19W27) produced a C9.9/1N flare on 11/0153 UTC. This region has shown growth in area and spot count in the last 24 hours but maintains its magnetic beta-gamma configuration. Region 9901 (N21W14) increase in magnetic complexity to a beta-gamma-delta configuration. Region 9904 (S16W36) produced a C9/1F flare on 11/1626 UTC with an associated Type II Radio Burst (608 km/s). Initial analysis at SOHO/LASCO imagery does not indicate an earth directed component. Two new regions were numbered today: Region 9906 (S16E40) and Region 9907 (S04E74)
IB. Solar Activity Forecast
Solar activity is expected to be low to moderate. Region 9893/9901 complex has the potential for a major event.
IIA. Geophysical Activity Summary 10-2100Z to 11-2100Z
The geomagnetic field was at quiet to unsettled levels. At 11/1800 UTC a greater than 10 Mev proton enhancement began with a current level of 1.0 pfu at geosynchronous orbit.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be unsettled to active. On Day two of the forecast period a weak CME shock is expected to arrive. On day three another possible CME shock is due to arrive and should result in unsettled to active conditions.
III. Event Probabilities 12 Apr to 14 Apr
Class M60%60%60%
Class X10%10%10%
IV. Penticton 10.7 cm Flux
  Observed       11 Apr 197
  Predicted   12 Apr-14 Apr  195/190/195
  90 Day Mean        11 Apr 202
V. Geomagnetic A Indices
  Observed Afr/Ap 10 Apr  004/007
  Estimated     Afr/Ap 11 Apr  009/012
  Predicted    Afr/Ap 12 Apr-14 Apr  010/012-012/015-015/020
VI. Geomagnetic Activity Probabilities 12 Apr to 14 Apr
A. Middle Latitudes
Minor storm05%10%15%
Major-severe storm01%05%05%
B. High Latitudes
Minor storm05%10%15%
Major-severe storm01%05%05%

All times in UTC

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