Density variations of galactic cosmic rays in magnetic clouds

Galactic cosmic ray behavior features in events when magnetic clouds that have been observed in interplanetary disturbances near the Earth are investigated. It is shown in most cases (but not in all) that the cosmic ray density behavior in the magnetic cloud near the Earth can be described by a simple parabolic distance dependence measured in gyroradii. Most magnetic clouds modulate cosmic rays by reducing their density, but there is a group of events (about 1/5) in which the cosmic ray density in the magnetic cloud increases. The extremum (minimum or maximum) of the cosmic ray density is often located closer to the cloud center rather than its edges. A number of factors that contribute to the model description are considered, and the contributions are estimated.