CME impacts Earth, sparks G2 - Moderate geomagnetic storm

CME impacts Earth, sparks G2 - Moderate geomagnetic storm

Coronal mass ejection (CME) produced by M1.6 solar flare at 06:40 UTC on October 9, 2021, reached DSCOVR spacecraft at 01:48 UTC and Earth at 02:30 UTC on October 12, 2021. The impact sparked a G2 - Moderate geomagnetic storm.

In 24 hours to 00:30 UTC on October 12, solar wind conditions were indicative of mildly enhanced and disturbed conditions likely due to heliospheric current sheet (HCS) proximity and weak coronal hole high speed stream (CH HSS) effects. Total interplanetary magnetic field (IMF) strength weakened from an early peak of 12 nT to an average of 5 - 6 nT. The Bz component varied, but was predominantly directed southward.

Solar wind speed at DSCOVR spacecraft rose sharply from 366 km/s at 01:42 UTC to 487 km/s at 01:48 UTC, signaling impact from October 9 CME.

Full halo CME produced on October 9, 2021. Credit: ESA/NASA SOHO LASCO C3

The CME reached Earth at around 02:30 UTC sparking G1 - Minor geomagnetic storm at 02:57 UTC and G2 - Moderate at 04:47 UTC.

G2 - Moderate geomagnetic storm potential impacts:

  • Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
  • Induced currents - Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms.
  • Spacecraft - Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
  • Radio - HF (high frequency) radio propagation can fade at higher latitudes.
  • Aurora - Aurora may be seen as low as New York to Wisconsin to Washington state.

CME influences are expected to wane on October 13, while weak isolated, positive polarity CH HSS influences may be noted, SWPC said.

October 14 is expected to be primarily quiet.


Note for readers new to space weather

This solar storm also sparked many clickbait articles across English tabloid media and other news portals whose only interest appears to be your views and clicks achieved through fear-mongering.

If you are interested in space weather, just keep calm and follow official sources like NOAA SWPC. There are great specialized websites out there and space weather enthusiasts you can follow on social media.

You can always come back here and visit our Space Weather category for solar activity articles without the fear factor.

Featured image credit: Nidheesh Dadheech @ Twitter


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