Two-Dimensional Phenomenological Model of Ring Current Dynamics in the Earth’s Magnetosphere

Modeling of Anisotropy Dynamics of the Proton Pitch Angle Distribution in the Earth’s Magnetosphere

“…To accurately calculate the perpendicular (α = 90 • ) anisotropy index γ ⊥ of the pitch angle distribution of charged particles at any time, one should use the formula [3]…”

“…The offered model, PheMRC 2-D, is based on the general two-dimensional Fokker-Planck equation for phase space density, which describes the radial and pitch angle diffusions and losses due to charge exchange and wave-particle interactions. It can be expressed by the following equation [3]…”

“…We also use the relationship between the differential particle flux j and the phase space density f : j = 2mEf . In detail in [3].…”

“…For example, modeling the pitch angle distribution on the dayside of the Earth's magnetosphere was considered in [1], and on the nightside of the magnetosphere -in [2]. In work [3] it has been offered two-dimensional Phenomenological Model of Ring Current dynamics in the Earth's magnetosphere (PheMRC 2-D). In these three works the non-stationary equation of pitch angle and radial diffusions numerically was solved in a range of pitch angles from 0 • up to 180 • .…”

“…The purpose of the given work is more exact quantitative research of anisotropy dynamics of the proton pitch angle distribution during the magnetic storm in the Earth's magnetosphere. Therefore it was used the two-dimensional Phenomenological Model of the Ring Current (PheMRC 2-D) [3], based on the physics and describing the perpendicular proton pitch angle distribution anisotropy index depending from the McIlwain parameter L and the geomagnetic activity Kp-index.…”