  We carry out a comparative analysis of the GALLEX-GNO solar neutrino data and
estimates of the solar internal rotation rate derived from the MDI
helioseismology experiment on the SOHO spacecraft. We introduce a statistic,
which we evaluate as a function of radius and latitude, that is a measure of
the degree of "resonance" of oscillations in the neutrino flux and the synodic
solar rotation rate at that radius and latitude. A map of this statistic
indicates that the probable location is deep in the convection zone near the
equator.
  We also examine the integral of this statistic over the equatorial section of
the convection zone. This provides a measure of the likelihood that the
variability of the solar neutrino flux, as measured by the GALLEX-GNO data, has
its origin in the equatorial section of the convection zone. We apply the
shuffle test, randomly reassigning measurements among runs, to estimate the
significance of the value of the statistic computed from the actual data. This
test implies that the result is significant at the 0.2% level. When, for
comparison, we repeat this analysis for the radiative zone, we find that the
integral resonance statistic is not significant.
  These results support earlier evidence for rotational modulation of the solar
neutrino flux.
