Abstract. We carry out a comparative analysis of Super-Kamiokande, SNO, and photospheric magnetic-field data for the interval in which these datasets overlap. This proves to be the interval of operation of the D 2 O phase of the SNO experiment. Concerning rotational modulation, we find that the magnetic-field power spectrum shows the strongest peaks at the second and sixth harmonics of the solar synodic rotation frequency [i.e. at 3ν rot and 7ν rot ]. We find that the restricted Super-Kamiokande dataset has a strong modulation at the second harmonic, as we found to be the case for the complete Super-Kamiokande dataset. The SNO D 2 O dataset exhibits weak modulation at that frequency, but shows strong modulation in the band corresponding to the sixth harmonic (too high a frequency to be detectable in the Super-Kamiokande dataset, which is available only in 5-day bins, whereas SNO data is available in one-day bins). We estimate the significance level of the correspondence of the SuperKamiokande second-harmonic peak with the corresponding magnetic-field peak to be 0.0004, and the significance level of the correspondence of the SNO D 2 O sixth-harmonic peak with the corresponding magnetic-field peak to be 0.009. By estimating the amplitude of the modulation of the solar neutrino flux at the second harmonic from the restricted Super-Kamiokande dataset, we find that the weak power at that frequency in the SNO D 2 O power spectrum is not particularly surprising. We also examine power spectra in the neighborhood of 9.43 yr −1 , which is the frequency of a particularly strong modulation in the entire Super-Kamiokande dataset. There is no peak at this frequency in the power spectrum formed from the restricted Super-Kamiokande dataset. It is therefore not surprising that we find (in agreement with the recent analysis by the SNO collaboration) that this peak does not show up in the SNO D 2 O dataset, either.2