摘要
The geomagnetic fields,which play important roles in the ionospheric dynamo,can greatly affect the global distribution of ionospheric electric fields,currents and other ionospheric electrodynamics phenomena.In the study of ionospheric electrodynamics phenomena,such as the longitudinal variations of ionospheric electric fields,the non-dipolar component of the geomagnetic fields must be taken into account.In this paper,we deduce a theoretical electric field model for ionospheric dynamo at mid-and low-latitude which adopt a modified magnetic apex coordinates system.In the new electric field model,the geomagnetic fields can be calculated from either the IGRF model or the dipole field model,and the neutral winds and conductivities are calculated based on empirical models.Then the dynamo equation for the electric potential is finally solved in terms of the line-by-line iteration method,and the ionospheric electric fields and currents are derived from the calculated potential.Our model can reproduce the main features of the ionospheric electrodynamics processes,so it will be a useful tool for the investigation of the upper atmosphere and ionosphere.
The geomagnetic fields, which play important roles in the ionospheric dynamo, can greatly affect the global distribution of ionospheric electric fields, currents and other ionospheric electrodynamics phenomena. In the study of ionospheric electrodynamics phenomena, such as the longitudinal variations of ionospheric electric fields, the non-dipolar component of the geomagnetic fields must be taken into account. In this paper, we deduce a theoretical electric field model for ionospheric dynamo at mid- and low-latitude which adopt a modified magnetic apex coordinates system. In the new electric field model, the geomagnetic fields can be calculated from either the IGRF model or the dipole field model, and the neutral winds and conductivities are calculated based on empirical models. Then the dynamo equation for the electric potential is finally solved in terms of the line-by-line iteration method, and the ionospheric electric fields and currents are derived from the calculated potential. Our model can reproduce the main features of the ionospheric electrodynamics processes, so it will be a useful tool for the investigation of the upper atmosphere and ionosphere.
基金
Supported by the KIP Pilot Project of Chinese Academy of Sciences (Grant No. KZCX2-YW-123)
National Natural Science Foundation of China (Grant Nos.40636032 and 40725014)
National Basic Research Program of China (Grant No.2006CB806306)
关键词
中低纬度
电子场
磁场
地理学
ionospheric dynamo, ionospheric electric fields, APEX coordinates
