Relation between cosmic ray anisotropy and sector structure

Annual averages of diurnal cosmic ray variations have been calculated separately for the days when the interplanetary magnetic field was away (A) from the sun and toward (T) the sun. Data from Deep River and Oulu neutron monitors for the period 1965-1975 have been used and both stations give similar results. Differences between A- and T-days indicate that the perpendicular gradient changes its direction near the reversal of solar polar magnetic fields