【摘要】 本文利用武汉电离层观象台的高频多普勒台阵、TEC台阵和加密频高图等多种观测资料,分析了1987年9月23日发生在我国境内的日环食的电离层效应,简要地讨论了光食过程的电离层变化,着重研究了食后电离层扰动以及这种效应的高度演变和传播特征.结果表明:1.在不同高度上电离层的光化过程的弛豫时间不同,光食效应有明显的高度差异;2.食后出现了电离层行扰,这种扰动的特性随高度变化十分复杂,但不同高度上扰动的水平传播方向都指向日食中心带.这种扰动的激发源不在环食中心带内,它的激发可能与日食时大范围的大气冷却收缩所引起的低层大气运动的不稳定性有关.更多还原

【Abstract】 During the annular eclipse of September 23, 1989, several kinds of observation, such as TEC and Doppler measurements in a three-station network as well as a rapid-run ionosonde, were simultaneously carried out at Wuhan Ionospheric Observatory to observe the ionospheric effects of the eclipse. Both the horizontal propagation and the vertical evolusion of the traveling ionospheric disturbances (TIDs) after the solar eclipse are investigated in detail. It is found that the TIDs in different ionospheric heights propagated to, instead of from, the central band of the eclipse with downward phase velocities. This may imply that the sources of the TIDs are located in the lower atmosphere far from the eclipse band. To explain this observation, it is suggested that a cool source, being abruptly set up in the shadow region of the solar eclipse during the process of the eclipse, caused the large scale contract movement of the air around it. The observed TIDs may be excited by the effects of the topography of the Qinghai-Xizang plateau on this atmospheric movement.更多还原