Variations of the ionospheric conductivity with different solar activities and geomagnetic conditions
不同太阳活动及地磁条件下的电导率分布变化

The ionospheric conductivity is influenced by solar activities and geomagnetic conditions and has some changes. We calculated the conductivity and the collision frequency between the electrons and ions through models NRLMSISE-00(Neutral Atmosphere Empirical Model-2000) and IRI2001(International Reference Ionosphere-2001).We discussed the seasonal change of the conductivities at 120?km and 300?km and their changes under different solar activities and geomagnetic conditions.The result shows that the conductivity distribution is affected by the sunlight, and changes with solar activities.The geomagnetic disturbance can affect the ionospheric conductivity,but the effect is smaller than that of solar variations.At 120?km,the geomagnetic disturbance leads to the opposite change between Pedersen conductivity and Hall conductivity at different latitudes.At 300?km, the geomagnetic disturbance makes the same trend for Pedersen conductivity and Hall conductivity,and the change extent is bigger than that at 120?km.But the change becomes larger in the direction of pole either at 120?km or 300?km.