武汉地区中尺度电离层声重波扰动的变化特性

利用武汉电离层观象台高频多普勒台阵的覆盖太阳活动高、低年份，长达５年的连续观测数据，采用小波分析等方法估算电离层声重波扰动（ＴＩＤ）的传播参量，通过这些参量对武汉地区电离层扰动形态和变化规律进行了系统分析研究．结果表明，观测到的中尺度电离层声重波扰动（ＭＳＴＩＤ）存在二个显著季变化，在传播速度和周期上有明显差异的优势传播方向：一个指向东北方，传播的方位角主要分布在３０°─７０°之间（０°为正北，以顺时针方向表示传播方位角），它在夏季出现率最大，冬季基本消失；另一个优势方向指向正南，方位角主要分布在１５０°─２２０°范围，主要出现在冬季．文中还给出了ＭＳＴＩＤ的年、日变化，并进一步探讨了其变化特性的可能形成机理．

VARIATION OF MEDIUM-SCALE TRAVELLING IONOSPHERIC DISTURBANCES AT WUHAN

years（1986-1990） HF Doppler array data at Wuhan, China were used for estimating propagation parameters of medium-scale travelling ionospheric disturbances（MSTIDs） by searval methods, such as wavelet analysis. The annual, seasonal and daily variations of MSTID have been studied. The most of features of MSTIDs are that there are two preferred propagation directions with apparent seasonal variations. One directed to north-east （azimuth distribute from 30°to 70°, 0° indicates north） have maximun occurrences in summer, minimun in winter, another directed to south （azimuth of 150°─220°） mainly observed in winter. in addition, the wave speed and period for two preferred direction MSTIDs are also different. Furtherstudy shows that the local source of AGW related to the meteorology of the QinghaiXizang Plateau may play an important role in causing the regional features of MSTIDs over Wuhan, China.