Earth's magnetosheath: a comparison of plasma flow direction between models and observations

Abstract. Observations of the plasma flow direction in the Earth's magnetosheath are compared with the help of three analytical magnetic-field models, namely Kobel and Flückiger (1994), Romashets and Vandas (2019), and Vandas and Romashets (2019), which all assume current-free fields in the magnetosheath. 47 magnetosheath passages by spacecraft are analyzed in detail and performance of the models are evaluated. It is concluded that the performances measured by mean angles between model and observed flow directions are comparable among the models (the difference of the mean angles is below about 1°), and that they are satisfactory on average (overall mean angles are below 5°). Therefore, a usage of the model by Kobel and Flückiger (1994) is recommended, because it is the simplest one and yields results much faster.