A shock wave in the Sun's chromosphere moving outwards from a large solar flare at a velocity of about 1000 km/s. A Moreton wave is visible in Hα light as an arc, sometimes moving for several hundred thousand kilometres, and may cause the winking of dark filaments in its path. Metre-wave radio bursts invariably accompany Moreton waves. They are named after the American solar astronomer Gail Ernest Moreton (1930–82).
Subjects: Astronomy and Astrophysics.