Time Relationship of Metre-Wave and 3-cm. Wave Bursts

Abstract

IT is known that solar bursts are observed over a very large range of wave-lengths. A single burst may extend over a large or small fraction of the range from centimetres to metres. Usually, bursts of strong intensity in the centimetre region are associated with great bursts observed on metre waves. It is generally believed that at the time of these bursts, radial ascension of ionized particles excites radio-frequency radiation at different levels in the solar atmosphere. Moreover, there are reasons for thinking that solar radio waves on the lower frequencies are emitted at a higher altitude in the solar atmosphere than those on the higher frequencies. As a result we observe a regular drift of the onset of the bursts towards the lower frequencies. The object of this communication is to discuss a relation existing between the times of commencement of the bursts observed on 3-cm. waves and on metre waves. This work is based chiefly upon measurements of the associated 3-cm. wave bursts made by means of an int erferometer¹.