Low-Energy Solar Cosmic Rays and Type IV Solar Radio Outbursts

Abstract

The relation of low-energy solar cosmic ray events to the type IV solar radio outbursts is examined statistically, using the data obtained during the IGY (1957-1958) and the IGC (1959). The solar radio emission data include those at frequencies 167, 200, 500, 1000, 3000 and 9500Mc/s. With respect to the sun-earth transit time of those cosmic rays, it is found that there are two types, viz., F type (Fast type) and S type (Slow type), their transit time being shorter in F type particles than in S type particles. These two types (F and S types) correspond to the different characteristics of type IV outbursts spectra. It is found that the intense emission in the centimeter-wave region of type IV outbursts is closely related to the generation of solar cosmic rays. The mechanisms of their acceleration in the solar atmosphere and their propagation in relation to type IV outbursts are also examined.