Evidence for spiral pattern in Saturn's magnetosphere using the new SKR longitudes

The periodicities in electrons observed in Saturn's magnetosphere are examined using the new longitude system based on a drifting signal of Saturn kilometric radiation (SKR). When averaged into longitude and range bins over 50‐day time periods, 28–48 keV electron intensities clearly evidence patterns that peak at successively increasing longitudes with increasing radial distance from Saturn. That is, the electrons form a spiral pattern in the quasi‐corotational frame of SKR longitude. The spiral has only one “arm” that extends from ∼10 RS to as far as ∼60 RS from the planet (where 1 RS = 60268 km); the “arm” migrates an average of ∼3.4° in longitude for every RS of radial distance. The spiral does not remain fixed in SKR longitude, but changes its relative position on time scales of ∼50 days. The “base” of one spiral appears connected with a postulated convection outflow at ∼330° longitude.