日食电离层效应

本文分析了1987年9月23日日环食期间,我国14个电离层站和1988年3月18日日全食期间两个站的垂测仪和偏振仪记录,并综合50年代以来历次日食电离层效应的观测结果,证实:1.E层和F₁层光食效应明显,F₂层动力学效应显著;2.f₀F₂存在日食日值大于、小于或等于控制日值三种典型情况;3.TEC食变曲线有凹陷和不凹陷两种典型情况,甚至出现日食日值大于控制日值的异常现象. 本文对F₂层和外电离层的动力学特征作了定性讨论,认为:空间等离子体温度急剧下降和沿场扩散是F₂层和外电离层日食效应的最主要因素;而磁赤道上空等离子体的沿场扩散、“喷泉”效应,热层风和全（环）食带方位是影响位于磁赤道异常区各电离层站日食电离层效应的主要因素.

THE IONOSPHERIC EFFECTS OF THE SOLAR ECLIPSE

In this paper, the observations and theoretical interpretations of the ionospheric effects of the previous 6 solar eclipses are summarized. The ionospheric observations of solar eclipse effects are made at 18 ionospheric stations of 14 provinces in China. The first one of the 6 solar eclipses occurred, on 20 June 1955, the last one on 18 March 1988. In addition to the ionospheric observations, the observations of Faraday rotation of satellite beacons and the whistlers were made some time during the solar eclipses. They have shown that:(1)The optical eclipse effects on the E and F1 region and the dynamic effect on the F2 region are all quite clear;(2)The values of f0F2 on the eclipse day, comparing with those in the control day, could decrease, increase or remain unchanged;(3)There are either concave or non-concave outline for the curves of the TEC, the values of the TEC on the eclipse day comparing with those in the control day could increase during the solar eclipse.The dynamic characteristics of the F2 region and outer ionosphere during the solar eclipses were also discussed briefly. It is found that striking decrease of the space plasma temperature and the space plasma diffusion along magnetic field lines are main factors of the solar eclipse effects on the F2 region and outer ionosphere, and the plasma diffusion along the magnetic field line over the geomagnetic equator, the fountain effect, the thermospheric wind and position of the zone of the total (annular) solar eclipse are important factors of the ionospheric effects of the solar eclipse on the magnetic equatorial anonaly.