In situ observations of the effect of a solar wind compression on Saturn's magnetotail

In this paper we explore the dynamic response of Saturn's magnetotail to an episode of solar wind compression that took place while Cassini was sampling Saturn's nightside equatorial magnetosphere in 2006. Following an initial increase in solar wind dynamic pressure the magnetosphere was compressed, but over several subsequent days the flaring of the tail increased as open flux built up in the tail lobes. Several days later the current sheet was displaced southward from its previously hinged position, and magnetic signatures consistent with the passage of a plasmoid were observed. Concurrently, Saturn's kilometric radio emissions were enhanced and the spectrum displayed a continuous extension to lower frequency, corresponding to radio sources detected at higher altitudes. We suggest that all of the above features are a common consequence of the impact of a solar wind compression on Saturn's magnetosphere.