Energy dependent time lag in the long-term modulation of cosmic rays

Summary. The intensity variations in the cosmic ray electron spectrum above 500 Mev observed outside the radiation belts from March 1968 to August 1971 are reported. The data show the existence of a large energy dependent hysteresis in the long-term modulation and two different types of steplike changes in the modulation parameter at rigidities below those observed with neutron monitors. The data indicate further that changes in the rigidity dependence of the modulation parameter occur mainly at rigidities above roughly 2 Gv. The assumption that time lag phenomena in the solar modulation reflect the effective size of the solar cavity is questioned, and alternative explanations of the energy dependent time lags are qualitatively investigated.