Formation of a Forbush Decrease in a Magnetic Cloud by the Electromagnetic Mechanism

• Published in: Physics of atomic nuclei Vol. 86; no. 6; pp. 1133 - 1137
• Main Authors: Petukhova, A. S., Petukhov, I. S., Petukhov, S. I.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.12.2023; Springer Nature B.V
• Subjects: Angular velocity; Cosmic rays; ELEMENTARY PARTICLES AND FIELDS/Experiment; Forbush decreases; Interplanetary space; Kinematics; Kinetic equations; Magnetic clouds; Magnetic fields; Magnetic properties; Mathematical models; Parameters; Particle and Nuclear Physics; Physics; Physics and Astronomy; Toruses; Velocity; Velocity gradient
• ISSN: 1063-7788; 1562-692X
• DOI: 10.1134/S1063778824010435

We calculate cosmic ray intensity using the model of the Forbush decrease formation in a magnetic cloud by the electromagnetic mechanism for three events. The properties of the Forbush decrease are determined by solving the Boltzmann kinetic equation without particle scattering. At the initial time, the magnetic cloud has the shape of a torus, for which geometric parameters such as velocity, velocity gradient, cross-sectional area, and angular dimensions are specified. The kinematic model determines the subsequent propagation of the cloud in interplanetary space. The magnetic field properties and the type of helical structure near the Sun are based on the Miller and Turner toroidal model. In interplanetary space, magnetic field components are determined by the frozen-in condition. The model properties of the velocity, velocity gradient, magnetic field components, and characteristics of the Forbush decrease roughly agree with measurements in three events. There are no free parameters in the Forbush decrease formation model.