Dynamic modeling of trapped particles

Understanding the dynamics of trapped particles is not simple, because storms are different and not too many satellites are orbiting at the same time with detectors aboard. In the past, general considerations have been made about radial diffusion, sources, and losses but at present, due to the increasing power of computers, new codes can help understand what is really happening to particles during storm periods in the trapped region. Physical considerations about four different codes are presented. The applications of full trajectory codes, codes using the guiding center approximation, three-dimensional diffusion codes, and four-dimensional diffusive-convective codes are given. In the near future, with some of these codes, it seems that a step will be passed in the modeling and comprehension of the physical phenomena occurring during such periods. We then will be able to identify the different kinds of storms and their implications on trapped particles, and may be make some predictions on the fluxes encountered by the satellites in the internal magnetosphere region.