不同太阳活动及地磁条件下的电导率分布变化  

Variations of the ionospheric conductivity with different solar activities and geomagnetic conditions

作　　者：纪巧[1] 马瑞平[1] 徐寄遥[1] 

机构地区：[1]空间天气学开放实验室中国科学院空间科学与应用研究中心

出　　处：《地球物理学报》2006年第5期1235-1242,共8页Chinese Journal of Geophysics

基　　金：国家自然科学基金(40225011;40336054);中国科学院知识创新项目(KZCX3-SW-217)资助

摘　　要：电离层电导率在不同的太阳活动和地磁条件下会发生变化.本文通过中性大气经验模式NRLMSISE_00(Neutral Atmosphere Empirical Model_2000,简称NRLMSISE_00)和电离层经验模式IRI_2001(International ReferenceIonosphere_2001,简称IRI_2001)计算电离层的电子、离子碰撞频率以及电导率,并简要讨论了120 km和300 km高度上的电导率在不同季节、不同太阳活动和地磁指数下的经纬分布.结果显示,电导率的分布与日照密切相关,且随太阳活动的变化而变化.磁暴时电导率随地磁活动的变化相对于随太阳活动的变化要小,在120 km高度,磁暴期间电导率在低纬地区和高纬地区发生不同变化,且Pedersen电导率和Hall电导率变化趋势相反,向两极靠近,电导率变化幅度略有增长;在300 km高度上,磁暴对低纬地区和高纬地区电导率的影响要比120 km处大,Pedersen电导率和Hall电导率变化趋势相同,且越向两极靠近电导率的变化幅度越大.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.

关 键 词：电离层电导率 碰撞频率 太阳活动指数 地磁指数 

分 类 号：P352[天文地球—空间物理学]