(a) Scatter plot of normalized power input to the magnetosphere, P_α/P_o, as a function of southward field in the GSEQ frame of reference, [B_S]_GSEQ, defined by [B_S]_GSEQ = −[B_Z]_GSEQ for [B_Z]_GSEQ < 0 and [B_S]_GSEQ = 0 for [B_Z]_GSEQ > 0. Grey dots are for 3-hourly means, orange dots are means in 1-percentile ranges of [B_S]_GSEQ and error bars are plus and minus one standard deviation in those ranges. The mauve line is a linear regression fit to the 3-hourly means. (b) The same as (a) for the fit residuals in (a), Δ(P_α/P_o), as a function of the difference in the half-wave-rectified southward fields in the GSEQ and GSM frames, [B_S]_GSEQ − [B_Z]_GSM. Data are from 1995 to 2017, inclusive.