The solar diurnal variation of the intensity of the nucleonic component of the cosmic radiation

Abstract

The diurnal variation of the intensity of the nucleonic component of the cosmic radiation detected at this laboratory through the period 1954–58 has been analysed. The results, together with previously reported neutron data, show that the direction of the anisotropy causing the diurnal variation has remained substantially constant at 60–70° east of the line joining the earth to the sun except during 1954 when the direction changed abruptly to become west of the earth-sun line. The amplitude of the diurnal wave shows considerable variation, closer in correlation with the planetary amplitude of magnetic activity A_p , than with relative sunspot numbers.