Viewing archive of Tuesday, 9 August 2011

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 2011 Aug 09 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 221 Issued at 2200Z on 09 Aug 2011

IA. Analysis of Solar Active Regions and Activity from 08-2100Z to 09-2100Z

Solar activity was high. Region 1263 (N17W83) produced an X6/2b flare at 09/0805Z, the largest x-ray event so far in Cycle 24. This flare was accompanied by multi-frequency radio emissions, including a Tenflare (710sfu), and Type II (1551 km/s) and IV signatures. A full halo CME was subsequently observed in LASCO C3 imagery at 09/0906Z. Initial plane-of-sky speed was estimated to be about 1000 km/s. Earlier in the period, a CME was observed in LASCO C3 imagery at 0406Z. This event was attributed to an M2/1b flare from Region 1263 at 09/03435Z. While the area of Region 1263 diminished over the last 24 hours, the longitudinal extent expanded, and the region ended the period as an Ehc type spot group with a beta-gamma-delta magnetic configuration.
IB. Solar Activity Forecast
Solar activity is likely to be low to moderate. A slight chance for an isolated X-class flare, and/or proton event, remains for Day 1 (10 August). Event probabilities are expected to gradually decrease as Region 1263 rotates around the west limb.
IIA. Geophysical Activity Summary 08-2100Z to 09-2100Z
The geomagnetic field was quiet to unsettled through the period under the continued influence of a coronal hole high speed stream. Solar wind speed at the ACE spacecraft was approximately 600 km/s for most of the period. The Bz component of the interplanetary magnetic field was predominantly near zero. The greater than 100 MeV protons crossed the 1 pfu event threshold at 09/0825Z, reached a maximum of 2 pfu at 09/0855Z, and ended at 09/1045Z. The greater than 10 MeV protons crossed the 10 pfu event threshold at 09/0845Z, reached a maximum of 26 pfu at 09/1210Z, and ended at 09/1715Z. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be predominantly quiet to unsettled for the next three days (10-12 August). Unsettled conditions are expected on Day 1 (10 August) as a weak remnant of the 08 August CME arrives. Currently, a return to mostly quiet conditions is expected on Days 2 and 3 (11-12 August). Analysis of the 09/0906Z CME is presently underway to determine its potential geoeffectiveness.
III. Event Probabilities 10 Aug to 12 Aug
Class M60%40%20%
Class X10%10%05%
Proton99%60%10%
PCAFYellow
IV. Penticton 10.7 cm Flux
  Observed       09 Aug 098
  Predicted   10 Aug-12 Aug  095/085/085
  90 Day Mean        09 Aug 096
V. Geomagnetic A Indices
  Observed Afr/Ap 08 Aug  008/010
  Estimated     Afr/Ap 09 Aug  008/008
  Predicted    Afr/Ap 10 Aug-12 Aug  010/010-007/007-005/005
VI. Geomagnetic Activity Probabilities 10 Aug to 12 Aug
A. Middle Latitudes
Active20%15%05%
Minor storm05%05%05%
Major-severe storm01%01%01%
B. High Latitudes
Active15%20%10%
Minor storm10%05%05%
Major-severe storm05%05%01%

All times in UTC

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