Analysis of Characteristics of Type Ⅲ Drift Pair Bursts

Six metric type Ⅲ bursts with bidirectional frequency drifts observed with the Acousto-Optic Spectrograph at the Yunnan Observatory during the 22nd solar cycle are analysed in the present article.These events respectively reveal that the demarcation frequencies between the positive and negative drift bursts are in between 244 MHz and 272 MHz. The radiation mechanism of the type Ⅲ drift pair events is also discussed from the observation characteristics.