Slowly Varying Component of Solar Radio Emission in Relation to the Solar Cycle

Abstract

IN a previous communication we showed¹ that the so-called slowly varying component (S-component) of solar radio emission, exhibiting the characteristic 27-day variation in the received flux, is limited only within the frequency range 470–29,000 Mc/s and that the amplitude of the characteristic variation would be maximum at a frequency over 4,000 Mc/s. However, the foregoing analysis was performed with the help of solar radio noise flux data for the International Geophysical Year period of 1.5 years only, that is, during the period when the Sun was in the most active form in the present solar cycle. It is quite logical to examine the data over a longer period with a view to seeing whether the above conclusions made for the S-component are also valid year to year throughout the solar cycle. We were thus prompted to study the slowly varying component of solar radio emission in relation to solar cycle.