Nonlinear Effect for Anisotropy of Charged Particle Pitch Angle Distribution at Geostationary Orbit

The new phenomenological model of a prediction of perpendicular anisotropy index of charged
\nparticle pitch angle distribution at geostationary (geosynchronous) orbit (GEO) in the Earth’s magneto-
\nsphere, and also in any circular orbit depending from the local time LT in an orbit and the geomagnetic
\nactivity index Kp is offered. Comparison of model with the numerous experimental data is lead. It
\nis proved, that the general analytical dependence of perpendicular anisotropy index of charged particle
\npitch angle distribution on GEO received as a first approximation can be used for conditions of mag-
\nnetically quiet time for quantitative forecasts and comparisons with experimental data on GEO. The
\nnonlinear effect is theoretically predicted for a difference between the maximal value of perpendicular
\nanisotropy index of charged particle pitch angle distribution and the minimal value of perpendicular
\nanisotropy index (in local midnight LT = 0 h) on GEO from the Kp-index of geomagnetic activity.
\nThe nonlinear effect for anisotropy of charged particle pitch angle distribution will be, possibly, to some
\nextent and on other radial distances from the Earth