Viewing archive of Saturday, 17 March 2012

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 2012 Mar 17 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 077 Issued at 2200Z on 17 Mar 2012

IA. Analysis of Solar Active Regions and Activity from 16-2100Z to 17-2100Z

Solar activity was moderate. Region 1435 (S26W37) grew rapidly overnight ending the period as a Dro type group with beta magnetic characteristics. Nearby Region 1434 (S22W27) produced an impulsive M1/Sf flare at 17/2039Z. This flare was accompanied by a Type II radio sweep (1140 km/s). A northward directed wave was visible in SDO/AIA 193 imagery. Region 1432 (N14W39), currently a Cro type group with beta magnetic characteristics, produced a C1 flare at 17/0312, but was generally quiet overnight. New Region 1437 (S34E15) was numbered today. It and the remaining regions were small, magnetically simple, and stable.
IB. Solar Activity Forecast
Solar activity is expected to be low with a chance for an isolated M-class flare all three days (18-20 March), particularly from the vicinity of Regions 1434 and 1435.
IIA. Geophysical Activity Summary 16-2100Z to 17-2100Z
Geomagnetic field activity ranged from quiet to active levels with isolated minor to major storm levels observed at high latitudes. This activity was in response to the continued presence of a high speed solar wind stream. Solar wind speed, measured at the ACE spacecraft, remained around 650 km/s while Bz ranged between +5 and -5 nT. The greater than 2 MeV electron flux at geosynchronous orbit reached high levels during the period.
IIB. Geophysical Activity Forecast
Geomagnetic field activity is expected to begin at unsettled levels and increase to active to isolated minor storm levels on Day 1 (18 March) as a CME from 15 March arrives. Activity levels are expected to be predominantly active on Day 2 (19 March), declining to unsettled levels on Day 3 (20 March) as effects from the CME subside. Analysis of the M1/Sf flare is ongoing to determine if it was associated with an Earth-directed CME.
III. Event Probabilities 18 Mar to 20 Mar
Class M30%30%30%
Class X05%05%05%
IV. Penticton 10.7 cm Flux
  Observed       17 Mar 102
  Predicted   18 Mar-20 Mar  100/100/105
  90 Day Mean        17 Mar 124
V. Geomagnetic A Indices
  Observed Afr/Ap 16 Mar  017/021
  Estimated     Afr/Ap 17 Mar  013/016
  Predicted    Afr/Ap 18 Mar-20 Mar  018/025-015/020-008/010
VI. Geomagnetic Activity Probabilities 18 Mar to 20 Mar
A. Middle Latitudes
Minor storm20%15%01%
Major-severe storm05%01%01%
B. High Latitudes
Minor storm25%20%10%
Major-severe storm35%25%05%

All times in UTC

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