武汉突发E层的季节变化及其与中层风的关系

通过对2018年武汉站（114.61°E，30.53°N）数字测高仪记录的数据统计分析，研究武汉地区突发E层的特征。研究发现:2018年武汉地区电离层突发E层的临界频率在夏季最高，在冬季有一个次增强现象，在春秋季较低；在正午前最大，在日落后出现小幅度提升，在日出前最低。利用指定动态全球大气气候扩展模型SD-WACCM-X模拟出2018年武汉上空90～140 km高度的平均风场，探讨突发E层与背景风之间的关系，揭示突发E层的形成机制。结果表明，半日潮汐分量可能诱导突发E层临界频率的半日变化，周日潮汐分量诱导突发E层临界频率的周日变化；突发E层的强度可能与纬向风场120 km高度处的风剪切有关。 

Seasonal Variation of the Sporadic E Layer over Wuhan and Its Dependence with Mesospheric Wind

Based on the statistical analysis of the dataset recorded by ionosonde at Wuhan station (114.61°E, 30.53°N) in 2018, characteristics of sporadic E layer over Wuhan area are studied. It is found that the critical frequency of sporadic E layer was the highest in summer, a secondary enhancement in winter, and it was very low in spring and autumn; and it was highest around noon, a secondary enhancement at sunset and the lowest before sunrise. Using the specified dynamics Whole Atmosphere Community Climate Model-extended (SD-WACCM-X) to simulate the average wind field over Wuhan at a height of 90～140 km in 2018, to reveal the formation mechanism of sporadic E layer. The results show that the semi-diurnal tidal component may induce a semi-diurnal change in the critical frequency of the sporadic E layer, and the diurnal tidal component induces a diurnal change in the critical frequency of the sporadic E layer. It is also found that the intensity of the sporadic E layer may be related to the wind shear at a height of 120 km in the zonal wind field.