【摘要】 我们对1976—1988年间的北京电离层站的 F₂区的临界频率（f₀F₂）作了 AR 谱分析,其结果是该站的 f₀F₂存在着9.4、13.7、28.1、33.4、55.1和91.0天的变化周期。对同一时间内的太阳相对黑子数 R 也作了分析,发现除了91天的 f₀F₂周期外,二者其它的变化周期对应的相当好,这说明 f₀F₂的这些变化主要受太阳活动的控制。更多还原

【Abstract】 In this paper,both f₀F₂ obtained from sounding in Beijing and sunspot numbers from 1976 to 1988 are calculated by AR spectral estimation.Periodical Variations are found with period 9.4,13.7,28.1,33.4,55.1 and 91.0 days in f₀F₂,and 9.5,13.6, 27.9,33.0,52.6 and 63.7 days in sunspot number.Good agreement exists between them except for periods of 91 and 63.7 days.It is clear that F₂—layer critical frequency f₀F₂ is under the control of solar activity.更多还原