The cosmic ray spectral modulation above 2 GV during the descending phase of solar cycle No. 19. IV: The influence on the attenuation coefficient of the nucleonic component

In this Part IV we study the influence of the primary cosmic ray modulation on the attenuation coefficient of the nucleonic component at different latitudes and altitudes. The direct investigation of the time behaviour of the stat10n attenuation coefficients is based on the largest amount of refined data, so far used, i.e. the revised data of the IGY neutron monitors 1957-1965 obtained in Part I and the IQSY supermonitor data 1965-1969. The results of the correlation between this time behaviour and the time changes of the nucleonic intensity are in agreement with the estimates based on the solar cycle modulation of the primary spectrum found in Part III. The results are also presented in a form suitable to their use for an accurate pressure correction of the data of the network of neutron monitors.