Statistical analysis of Solar Type III radio bursts observed by RPWS experiment in 2004-2017 during the Solar cycles 23-24

We report on Solar Type III radio bursts observed by the radio and plasma wave experiment (RPWS) onboard Cassini spacecraft. RPWS instrument measures electric field over a frequency range from few Hz and up to 16 MHz (Rucker et al., 2008). A statistical survey of almost 1000 solar bursts recorded in the time interval from January 2004 to September 2017 is considered in this study. Those solar bursts occurred in the end of the 23 solar cycle (2004-2008) and during the 24 solar cycle (2008-2017). Type III observational parameters are taken into consideration like the emission frequency, the time occurrence, the intensity level, and the heliospheric location (i.e. distance, longitude and latitude) of the spacecraft when the solar burst has been detected. This leads to insist on three main aspects: (a) the occurrence rate of the solar burst, (b) the corresponding electron density derived from heliocentric empirical models and (c) the most plausible source regions at the origin of the Type III bursts. Those characteristics allow us to discuss how Type III bursts are linked to the ecliptic spatial expansion of the Archimedean spiral emerging from the Sun, crossing the Earth’s orbit and reaching the Saturn’s orbits.