Fr.: onde de Moreton
A large-scale → shock wave observed in Hα on the Sun's → chromosphere that is generated by the impact of a → solar flare. Moreton waves expand outward at about 1,000 km/s, and may travel for several hundred thousand kilometers. They are accompanied by meter-wave radio bursts.
Named after the American astronomer Gail E. Moreton (1960, A.J. 65, 494); → wave.