Comment on “Magnetic phase structure of Saturn's 10.7 h oscillations” by Yates et al.

Yates et al. [2015, hereinafter YSD] have recently provided evidence which appears to cast doubt on the postequinox phases and periods of the northern and southern Saturn planetary period oscillations (PPOs) derived in studies of Cassini magnetic field data by Andrews et al. [2012] and Provan et al. [2013] (hereafter A and P, together AP) and suggest that the model values are “in need of refinement.” Their methodology consists of plotting field data versus the oscillation phases determined by AP from quantitative analysis of these same data and qualitatively examining whether the peaks and troughs of the oscillations observed on successive spacecraft revolutions (Revs) “line up” with the phase in the manner expected. Since the AP methodology also focuses directly on oscillation phase and employs quantitative means to “line up the peaks,” the negative findings of YSD represent a considerable surprise.