upper trough

• 高空槽

upper trough的用法和样例：

例句

1. The squall line is a kind of instable and strong convective weather caused by the air with upper-layer dry and lower-layer wet in front of the upper-troposphere trough.
   分析指出，该飑线系统是由高空槽前型的上干下湿引起的不稳定强对流天气。