On some aspects of Io and non-Io related sources on Jovian decametric radio emission during its northern declinations

The causes of decametric radio emission from Jupiter and their activities have considered at length. Some remarkable effects about the satellite Io of Jupiter and non-Io related sources responsible for decametric emissions as recorded in our observatories at Kalyani (22.97° N, 88.43° E) and at Kolkata (22.58° N, 88.42° E) at 20.1 MHz for the period from January 2011 to March 2015 have been critically examined. The probability of detecting radio sources A, B, and C against Jupiter's Central Meridian Longitude (CML) have taken into consideration. We have examined the occurrence probability against Io phase and CML and also plotted the year vs. average duration of presence of Jupiter in West Bengal sky for the years 2011 to 2015, showing that the Jupiter is in declining phase in the northern hemisphere. A comparison of the occurrences of Io and non-Io events of all the three categories during spring, summer, autumn and winter have then been made, analyzing the probability of occurrences of Io related and non-Io related events during the four seasons. Finally some typical records have been chosen to illustrate the characteristic variations of the received radio signals associated with different types of events.