equatorial trough

This phenomenon occurs when the effect of strong volcanic activities begin to weaken and the equatorial trough fills up and retreats southwards .

这种现象发生在强火山活动影响开始减弱，赤道槽南移填塞以后。

Our analysis concentrated on the locations and the corresponding TEC values of northern crest , equatorial trough and southern crest , and also the width of the trough and the ratio of crest to trough .

重点分析了南北驼峰和赤道槽的位置和对应处的TEC值、谷宽和峰谷比。