Coronal mass ejection arrival

Tuesday, 19 January 2016 01:31 UTC

Coronal mass ejection arrival

Yesterday around 20:55 UTC we saw a minor shock in the solar wind which is likely the arrival of the filament coronal mass ejection of 15 January.

More about that eruption can be read here.

The solar wind speed increased from 300 to 370km/s when the shock passed ACE and the IMF slowly turned into a prelonged negative (southward) orination averaging out at about -6nT. At the time of writing, the observed Wing-Kp index hasn't increased beyond -3 but the NOAA SWPC did report that the Kp4 threshold (active geomagnetic conditions) has been reached. Active geomagnetic conditions (Kp4) remains possible in the hours ahead if the direction of the IMF (Bz) continues to be southward. Sky watchers near the US-Canadian border should be alert for auroral displays in the hours ahead.

Any mentioned solar flare in this article has a scaling factor applied by the Space Weather Prediction Center (SWPC), the reported solar flares are 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.

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