Number of detected SEDs per hour in logarithmic scale as a function of time (in DOY 2007/2008, upper panel), and radial distance of Cassini as function of time (lower panel). This figure gives the first part of SED storm F from late November 2007 until 9/10 March 2008. The periapse times are marked by dotted vertical lines in both panels. The horizontal lines at the top indicate times when SED episodes lasted for a full Saturn rotation.