Relationships between field-aligned currents and particle precipitation

The field-aligned currents and particle precipitation play important roles in the magnetosphere-ionosphere coupling. The polarities and densities of large scale field-aligned currents from the DMSP magnetometer data 1983-2005 were determined using an automated algorithm. The particle precipitations often have characteristics that reflect their source regions in the magnetosphere, which led to the development of the automatic region identification schemes. The particle precipitation regions from the DMSP SSJ4 particle data were also determined from 1983-2005. The relationships between the field-aligned currents and the particle precipitation regions on the dayside were explored and identified. In the dayside open region, the solar wind-magnetosphere coupling issues were investigated.