Solar flares, on the other hand, directly affect the ionosphere and radio communications at the Earth, and also release energetic particles into space. Therefore, to understand and predict 'space weather' and the effect of solar activity on the Earth, an understanding of both CMEs and flares is required.

Particles from solar flares can distort Earth's magnetic field, which in turn, disrupts navigation systems, cause surges in electrical systems causing damage and blackouts, and damage or disrupt satellites.