The position of dayside aurora (as measured from South Pole station in 1980) is compared with the interplanetary magnetic field Bz component and to the AE index. The results are consistent with our earlier work showing a close relationship with AE and little correlation with Bs. Two recent papers have presented data that were interpreted to indicate a dominant Bz correlation. A reconsideration of the data sets used in those papers does not support dominant Bz dependence, and in fact reaffirms a close dependence on AE. We conclude that the position of the dayside cusp is largely controlled by substorm processes internal to the magnetosphere rather than by direct merging and erosion processes with the interplanetary field.