极区电子沉降对电离层影响的模拟研究

在极区电离层模式中,考虑了软电子沉降引起的电离,并对差分方法的应用提出了改进意见.模拟了不同特征的沉降电子对极区电离层的影响,发现平均能量低的电子束能够形成明显的电离层F层,平均能量较高的电子束能使得最大电离的高度下移,形成明显的E层,甚至其电子浓度高于F层.将电子沉降的卫星测量结果作为电离层模型的输入,所得F层临频与观测结果符合较好.通过分析中山站电离层统计结果,综合电子沉降在极隙区的分布特征和上述模拟结果,认为中山站磁中午现象主要由电子沉降所致.

SIMULATION STUDY ON THE INFLUENCES OF THE PRECIPITATING ELECTRONS ON THE POLAR IONOSPHERE

A simulation study on the effects of precipitation electrons on the polar ionosphere is carried out in this paper. Soft electron precipitation is considered in considered in constructing the polar ionospheric model, and improvements are made in applying finite differential scheme for solving the ionospheric model equations. When only soft electron precipitation ionization is considered, a typical ionospheric F layer can be obtained, while precipitating electrons with higher characteristic energy have maximum ionization rate at lower height for form distinct ionospheric E layer. The ionozation density of the E layer becomes even greater than the F layer. Taking the statistical results of precipitating electrons as model inputs at the cusp region latitudes, the simulation results agree well with observation. Comparing the simulation results and statistical results of ionospheric F layer occurrence with statistical distribution of precipitating electrons at the cusp latitudes, we point out that the so called magnetic local noon effect at Zhongshan Station can be interpreted as the effects of precipitating electrons.