Cosmic ray anisotropy before and during the passage of major solar wind disturbances Original Research Article

Major disturbances of the interplanetary medium have a significant impact on cosmic ray flux and anisotropy, affecting the first harmonic as well as higher-order terms. Cosmic ray phenomena are observed not only during solar wind disturbances, but also prior to their arrival at Earth, and are thus of major importance to forecasting space weather. Using the worldwide network of neutron monitors, we have studied the cosmic ray anisotropy associated with major magnetic storms, mostly between 1978 and 1982. In this paper we discuss and illustrate their common features.