Coronal hole faces Earth

Saturday, 8 September 2018 - 12:36 UTC

Coronal hole faces Earth

A high speed coronal hole solar wind stream arrived at our planet yesterday from a small equatorial coronal hole but it did not produce much geomagnetic activity here on our planet. While the solar wind speed increased to above 500km/s, the north-south direction of the IMF stayed mostly northward and little geomagnetic activity was observed. The Kp-index never increased above Kp2 yesterday. However, we are soon getting another chance for some nice auroral displays as yet another coronal hole faced our planet yesterday.

Our automated coronal hole detection system did its job and an alert was posted on Twitter and as a push alert:

Facing our planet yesterday was a southern extension of the northern hemisphere polar coronal hole stretching all the way to the solar equator. Compared to the previous rotation, this coronal hole increased slightly in size. Last time around, this solar wind stream caused active geomagnetic conditions which stands for a Kp of 4.

This coronal hole solar wind stream is likely to arrive at our planet on 10 September and once again, active geomagnetic (Kp4) conditions are possible.

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