The latitudinal dependence of whistler ‘ghost’ delay times Original Research Article

A ‘ghost’ whistler group is one that follows a similar whistler group after a fixed and repeating time interval. This phenomenon was observed at Marion Island in the southern hemisphere. During a ninety minute period 11 whistler groups were followed, after a time interval of 600 ms, by ‘ghost’ groups. An explanation of this non-random time delay is that a component of the first group, on its way to the southern hemisphere resonates with counter-streaming electrons, close to the equatorial plane, causing some of them to diffuse in pitch angle and precipitate into the northern atmosphere. Entering the atmosphere the electrons trigger by some means, a second atmospheric discharge that produces the ‘ghost’ group. If this explanation is correct then the time delay between a ‘ghost’ and its whistler should vary with latitude. In this paper we calculate these time delays as a function of latitude. If ‘ghosts’ are found with delays that corresponded to these values it would be a powerful verification of the theory.