Prediction Of High Latitude Geomagnetic Disturbances Based On Weimer Ionospheric Electrodynamics Model

Geomagnetic disturbance is an important phenomenon in space weather,the severe disturbance of the geomagnetic environment has an important impact on ground-based technical systems.Accurate prediction of geomagnetic disturbance can provide important information for responding to space weather disasters,thereby reducing the impact of disasters.This paper develops a simulation method for geomagnetic disturbances in high latitudes based on Weimer electric potential and magnetic potential models and compared with the ground station observation data to verify the validity of the model prediction.The disturbance of the surface magnetic field is mainly affected by the ionospheric current system.First,the Weimer model is used to calculate the ionospheric equivalent current distribution.Then,the relationship between the three components of the geomagnetic disturbance and the current is derived based on the Biot-Savart law.The input parameters of the model are upstream solar wind speed,solar wind density,interplanetary magnetic field and dipole tilt angle.According to the official calculation method of the geomagnetic index,the corresponding geomagnetic index is deduced from the calculation results of the model and compared with the observation value of the geomagnetic stations.The basic agreement between the calculation results of the model and the observation results of geomagnetic stations with different latitudes and longitudes show that the calculation method in this paper can effectively simulate the characteristics of geomagnetic disturbance during geomagnetic storms,and the comparison results of the geomagnetic index show that the calculation method in this paper can make an effective prediction of the geomagnetic disturbance.The results of this paper laid an important foundation for the future development of geomagnetic field prediction models in high latitudes.In order to make up for the non-uniformity of the distribution of geomagnetic stations currently used to calculate the Kp index,it does not fully become the deficiency of the global magnetic index,twenty-four virtual stations with evenly distributed longitude and latitude are set at equal intervals of longitude in different magnetic latitude zones.Using the calculation method in this paper,the geomagnetic Ks index of the virtual station is obtained,then comparative analysis of Kp index with geomagnetic station,the results show that the geomagnetic index of the virtual station can better describe the overall change of geomagnetic disturbance during the magnetic storm,and has the characteristics of changing with latitude and longitude.It can well show the geographical distribution characteristics of geomagnetic disturbances,so as to provide better and more comprehensive services for space weather forecast.