低纬100—200km间电子数密度的变化

利用光化平衡模式计算了低纬100—200km间白天电子数密度的变化。求得E-F₁谷区的谷深,谷宽、谷高的变化特征。获得如下结果:a.太阳活动明显影响电子数密度随高度及太阳天顶角的变化,发现太阳活动指数与电子数密度间不仅存在正相关,而且存在负相关;b.太阳活动明显影响E-F₁谷区的形态。在一定太阳活动条件下,对同一太阳赤纬和地理纬度,谷深、谷宽与太阳天顶角的关系难以用一简单函数来表示;c.太阳耀斑、地磁活动对该区电子密度有明显影响;d.在讨论100—200km间电子密度时不能忽略O⁺（2P）和NO的光电离率。

VARIATION OF IONOSPHERIC ELECTRON DENSITY IN THE 100-200km HEIGHT REGION AT LOW LATITUDES

Using the photochemical equilibrium daytime model,the electron density profiles in the 100-200 km region at low latitudes are calculated.The characteristics of the depth and width of E-F1 valley are also analysed.The main results obtained are: (1) the variation of electron density with height and solar zenith angle depends on solar activity levels.It is found that the correlation of electron density with solar activity indices can be both positive or negative;(2) the solar activity can affect the morphology of E-F1 valley.Under a certain solar activity level,the relation between the width and depth of valley and solar zenith angle can not be represented by a simple function at a given solar declination and geographical latitude;(3) the solar flare and geomagnetic activity influence obviously the distribution of the electron density;(4) O+(2P) and photoionization of nitre oxide may play a significant role in the 100-200 km height region.