北半球中低纬大气太阴潮汐对Es层的影响

Effects on Sporadic E Layer of the Lunar Atmosphere Tide at Middle Latitudes in The Northern Hemisphere

本文采用中低纬度数个台站的数字测高仪观测数据分析了Es层参数的大气太阴半日变化,结果表明:Es的临界频率(foEs)、遮蔽频率(fbEs)及虚高(h'Es)中均存在太阴半日周期的振荡。foEs和fbEs的太阴半日潮日变化及季节变化趋势非常相似,只是foEs太阴半日潮的幅度大于fbEs太阴半日潮的幅度,两者的相位几乎无差值。中低纬5个台站Es层参数的太阴半日潮幅度和相位的日变化值、季节变化值均不同,随纬度变化。foEs和h'Es的太阴半日潮存在年变化,在不同年份的相同月份,Es太阴半日潮的幅度和相位均有不同。值得提出的是我们还发现武汉foEs和h'Es的太阴半日潮最大值和武汉中层和低热层大气太阴半日潮汐风最大值出现的月份相同。

Using the data of several ionosondes,the influence of lunar atmosphere to Es-layer is analyzed in this paper.It showed： there is lunar semidiurnal oscillation in the critical frequency（foEs）,blanketing frequency（fbEs） and virtual height（h＇Es） of Es-layer.The diurnal and seasonal variations of lunar tide in foEs and fbEs are very similar except the amplitude of foEs is bigger than the fbEs one.The phase’s difference of foEs and fbEs is very small.The diurnal and seasonal variations of lunar semidiurnal tide in Es are different in five stations of low-middle latitude in northern hemisphere.It varies with latitude.Both the foEs and h＇Es of the lunar semidiurnal tide have year-to-year variation.At same month in different years,the amplitude and phase of the lunar semidiurnal tide in Es maybe different.It should be to point out that the lunar semidiurnal tide in Es and at MLT region in Wuhan station reach the maximum values in the same month.