Procedure

To properly study the relationship between the solar wind driver of ionospheric convection and $\Phi_\mathsf{PC}$, care must be taken in selecting periods when (1) the measured solar wind conditions are known with some degree of certainty to be geoeffective, and, (2) the ionospheric data provide sufficient coverage in suitable locations to adequately define $\Phi_\mathsf{PC}$. The details of the selection criteria, and the subsequent decimations of the data are described in sections 2.1 and 2.3.