夜光云

yè ɡuānɡ yún

夜光云

1

夜光云是在夏季极地中圈顶之上形成的更广泛更持久的层的参差不齐的延伸。

Noctilucent clouds are ragged extensions of a more widespread and more permanent layer which forms over the summer polar area at the mesopause .
2

在过去几年中，我们对夜光云已经取得了相当认识，但其形成和演进机制仍然是一个热点研究课题。

Much about noctilucent clouds has been discovered only over the past few years , while how they form and evolve remains a topic of active research .
3

上面这张本月初拍摄的照片中，黄昏后的夜光云呈网状，在加拿大亚伯达的埃德蒙顿上空以怪异的白光与整座城市交相辉映。

Pictured above earlier this month , a network of noctilucent clouds cast an eerie white glow after dusk , above the the city of Edmonton , in Alberta , Canada .