The asymmetric geomagnetic disturbance field in low latitudes and its dependence on interplanetary disturbances

Using 3-minute data of magnetic observations in lower latitudes, the asymmetric magnetic disturbance field in lower latitudes is calculated for 4 different storms, and the dependence of this asymmetry on the activity of the solar wind and the interplanetary magnetic field is investigated. Here, different asymmetry parameters, separate for the geomagnetic X and Y component, have been calculated. It can be supposed that the observed asymmetry is not so much a consequence of a partial ring current but rather of a current system described by Crooker and Siscoe (1981). The results show that besides interplanetary processes magnetospheric ones too are responsible for the generation of the asymmetric disturbance field. (author)