Abstract

Radio observations serve as a powerful tool to study the physical conditions of the radio emitting sources for understanding the characteristics of solar atmosphere. It is also a useful method for understanding the physical properties and the dynamics of the solar corona. It is evident from various experimental observations that the recent 23–24 solar cycle minimum was elongated for much longer time compared to previous minima. In this paper, the mid-range periodicity (in the range of 50–250 days) for non-magnetic components of solar radio flux at eight discrete frequencies viz. 245, 410, 610, 1415, 2695, 4995, 8800 and 15400 MHz during the extended solar minimum period (2007–2009) have been explored using Lomb-Scargle periodogram technique. The periodicities obtained in the mid range (50–250 days) for dierent frequencies during this minimum have been identified with the periodicities within the range of standard deviation obtained from dierent analysis for dierent time span with dierent phase of previous solar cycles by dierent workers. The observations of basal component (non magnetic component of solar radio flux) are interpreted in terms of the internal dynamics of the Sun. The obtained periodicities also provide physical information about the source region of the solar atmosphere.