Viewing archive of Thursday, 20 January 2005

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 2005 Jan 20 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 020 Issued at 2200Z on 20 Jan 2005

IA. Analysis of Solar Active Regions and Activity from 19-2100Z to 20-2100Z

Solar activity was high. Region 720 (N14W70) produced an X7/2b flare at 0701 UTC, which was accompanied by Type II and Type IV radio sweeps. There is one image from the LASCO C2 coronagraph which shows an associated CME off the northwest limb at 0654 UTC. However, shortly after this observation the coronagraph data became difficult to use due to high levels of energetic particles. Region 720 continues to be large, with a sheared magnetic delta configuration along an east-west polarity inversion line.
IB. Solar Activity Forecast
Solar activity is expected to be moderate to high. Region 720 continues to have potential for producing an additional major flare. The location of Region 720 on the disk also implies that there is a fair chance for more energetic particles in association with future major flare activity.
IIA. Geophysical Activity Summary 19-2100Z to 20-2100Z
The geomagnetic field was quiet to active during the past 24 hours. Solar wind speeds were elevated (700-900 km/s) from the start of the interval up through at least 0700 UTC, after which the ACE real-time SWEPAM data became unusable due to elevated energetic particle flux. The interplanetary magnetic field, however, was weak with fluctuations between -4 nT to +6 nT. A new injection of protons was observed at 0650 UTC in association with the X7 flare. The greater than 100 MeV protons rose rapidly and attained a maximum of 652 PFU at 0710 UTC. The 100 MeV flux has been declining steadily since then. This high flux level makes this the largest greater than 100 MeV proton event observed since October 1989. A greater than 10 MeV proton event was in progress at the time of the new injection, but the new particles quickly increased the flux from initial values around 40 PFU to a peak value in the past 24 hours of 1860 PFU at 0810 UTC.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be predominantly unsettled to active for the next three days. Today's CME (associated with the X7 flare) is not expected to produce anything more than a glancing blow due to its direction away from the Sun-Earth line. The greater than 10 MeV flux is expected to remain above event threshold for at least another 24 hours.
III. Event Probabilities 21 Jan to 23 Jan
Class M90%90%80%
Class X30%30%20%
PCAFin progress
IV. Penticton 10.7 cm Flux
  Observed       20 Jan 123
  Predicted   21 Jan-23 Jan  115/105/095
  90 Day Mean        20 Jan 108
V. Geomagnetic A Indices
  Observed Afr/Ap 19 Jan  031/062
  Estimated     Afr/Ap 20 Jan  012/015
  Predicted    Afr/Ap 21 Jan-23 Jan  015/025-015/020-010/020
VI. Geomagnetic Activity Probabilities 21 Jan to 23 Jan
A. Middle Latitudes
Minor storm20%20%15%
Major-severe storm15%15%05%
B. High Latitudes
Minor storm20%20%15%
Major-severe storm15%15%10%

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