Coronal mass ejection arrival

Thursday, 7 September 2017 03:31 UTC

Coronal mass ejection arrival

While we were catching some much needed sleep, the coronal mass ejection from Monday's M5.5 solar flare arrived at Earth. Our alert system detected the impact and send out a tweet and a push alert when the shock arrived at DSCOVR around 23:08 UTC.

The coronal mass ejection was a bit slower than expected as it was fashionable late (what's new) and we have to speak of a fairly disappointing impact. The solar wind speed increased from 430km/s to about 600km/s which while decent, is nothing too special. The total strength of the IMF jumped initially to 15nT but is now somewhere around the 6 to 8nT mark. The Bz was northward until about 02:00 UTC but is now slightly southward.

These numbers are nowhere near good enough for moderate G2 geomagnetic storm conditions and only high latitude sky watchers will enjoy this one as only active geomagnetic conditions (Kp4) have been observed so far.

But there is more to come. The CME from yesterday's X9 solar flare is expected to arrive early on Friday 9 September 2017! We have to hope that the X9 CME will give us a better storm than this!

Do be sure to keep on following the data live here on the website as conditions can change from minute to minute.

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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