Viewing archive of Sunday, 30 December 2001

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 2001 Dec 30 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 364 Issued at 2200Z on 30 Dec 2001

IA. Analysis of Solar Active Regions and Activity from 29-2100Z to 30-2100Z

Solar activity has been moderate. Early in the period, newly numbered Region 9767 (S23E73) produced an M2/1f event at 29/2256 UTC. This region is the likely source of the X-class flare and CME activity of 28 December, and has now rotated into view. The region appears to be of significant size and magnetic complexity, but is current location near the east limb prevents a full analysis of it's characteristics. Other activity during the same period included a long duration M1 x-ray enhancement during 29/1950-2355 UTC, with an associated west limb CME evident in LASCO imagery, though appearing to lack any significant earth-directed component. Other regions on the visible disk were mostly quiescent, with a few minor C-class events observed. An additional new region was also numbered today, Region 9766 (N05E62).
IB. Solar Activity Forecast
Solar activity is expected to continue at predominantly moderate levels, with a fair chance for isolated major flare events during the next three days.
IIA. Geophysical Activity Summary 29-2100Z to 30-2100Z
Geomagnetic field activity has been quiet to active. Most of the period was dominated by ongoing effects from yesterday's shock passage, with an extended period of southward IMF producing active conditions during 30/0300-0900 UTC. Late in the period, an additional shock passage was observed at the ACE satellite at 30/1932 UTC, followed by a sudden impulse of 27 nT observed at Boulder at 30/2010 UTC. This event is presumed to be an early arrival of effects from the powerful X-class event of 28 December. The greater than 10 MeV proton flux at geosynchronous orbit has fluctuated near the event threshold value of 10 pfu for most of the day, though now appears to be undergoing some enhancement due to the recent shock passage. As a result of near-threshold activity, a 10 MeV proton event has been in progress since 30/0245 UTC.
IIB. Geophysical Activity Forecast
With the arrival of the most recent shock passage, geomagnetic field conditions are expected to be unsettled to active, with minor storm conditions possible during the first day of the forecast period. An enhancement of activity due to additional shock effects are also possible within the first two days, due to expected effects from the west limb CME of 29 December. Predominantly unsettled and quiet conditions are expected thereafter as shock passage effects wane. The 10 MeV proton event in progress is expected to end within the next 12-24 hours.
III. Event Probabilities 31 Dec to 02 Jan
Class M75%75%75%
Class X15%15%15%
IV. Penticton 10.7 cm Flux
  Observed       30 Dec 247
  Predicted   31 Dec-02 Jan  250/250/245
  90 Day Mean        30 Dec 225
V. Geomagnetic A Indices
  Observed Afr/Ap 29 Dec  013/010
  Estimated     Afr/Ap 30 Dec  018/018
  Predicted    Afr/Ap 31 Dec-02 Jan  020/020-015/015-012/010
VI. Geomagnetic Activity Probabilities 31 Dec to 02 Jan
A. Middle Latitudes
Minor storm20%10%05%
Major-severe storm05%01%01%
B. High Latitudes
Minor storm25%15%05%
Major-severe storm05%01%01%

All times in UTC

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