中文摘要：

利用COSMIC掩星2009年电子密度剖面数据,筛选数据进行网格划分,网格内数据统计平均,基于球谐函数计算模型值,分析电离层中低纬度地区最大电子密度的地磁季节变化、昼夜测分布相对变化,及地磁活动对电子密度的分布影响.结果表明,最大电子密度昼测值明显高于夜测值,在中纬度部分区域增大明显.电子密度昼测值在地磁活动期间高度150-550 km中低纬度范围为正相扰动,随纬度变化存在区域差异,随高度增加,扰动加强.

英文摘要：

Electron density profile data are collected in 2009 based on COSMIC occultation observation,and its statistical averages are calculated in each cell.Utilizing spherical harmonic function and calculating model values,we analyze the geomagnetic season variations of the maximum electron density and its distribution variations in the daytime and nighttime at mid and low latitude.We also discuss changes of electron density during geomagnetic activity.Research shows that the value of maximum electron density in the daytime was significantly higher than that of maximum electron density in the nighttime.Increase is particularly evident in the mid-latitude part of the region.The enhanced anomalous electron density disturbances took place from 150 km to 550 km altitude at mid and low latitude during geomagnetic activity.The values change with the latitude and increases with height.