In a Coronal Mass Ejection?

Coronal Mass Ejections (CMEs) are large expulsions of plasma and magnetic field from the Sun's corona. ... This can result in the sudden release of electromagnetic energy in the form of a solar flare; which typically accompanies the explosive acceleration of plasma away from the Sun – the CME.

What can a coronal mass ejection do to the earth?

Impact on Earth

When the ejection is directed towards Earth and reaches it as an interplanetary CME (ICME), the shock wave of traveling mass causes a geomagnetic storm that may disrupt Earth's magnetosphere, compressing it on the day side and extending the night-side magnetic tail.

What does the coronal hole do?

Scientists call these "open field lines." Plasma flowing upward through the corona can more easily escape into space along these open magnetic field lines at coronal holes. This escaping plasma produces faster flowing solar wind than at other locations on the Sun.