ION FLUX IN THE MAGNETOSHEATH: RESULTS FROM GAS-DYNAMIC MODELLING AND INTERBALL-1 MEASUREMENTS

A BSTRACT : In this work, the possibilities of the magnetosheath-magneto-sphere model for describing the plasma parameters in the magnetosheath are demonstrated. We consider the problem of a flow around a body (the Earth’s magnetosphere) with two movable boundaries – the bow shock (BS) and the magnetopause (MP). The grid-characteristic method is applied to describe an ideal gas flow in the transition region (magnetosheath). A theoretical finite element model and the semi-empirical Tsyganenko model are used to describe the magnetic field in the magnetosphere. The model allows a self-consistent determination of the magnetosheath boundaries for a given momentary state of the solar wind. For these input parameters the three-dimensional solution in the transition region is calculated. An analysis of the ion flux was made based on the model and the data measured by the Interball-1 satellite in several cases of magnetosheath crossings. The advantages and limitations of the model for describing the magnetosheath flow are analyzed.