Optical phenomena, such as rainbows and halos, occur when light shines through cloud particles. Rainbows are seen when sunlight from behind the observer strikes the raindrops falling from cumulonimbus clouds. The raindrops act as tiny prisms, bending and reflecting the different colors of light back to the observer’s eye at different angles and creating bands of color. Halos are seen when sunlight or moonlight in front of the observer strikes ice crystals and then passes through high, thin cirrostratus clouds.
- optical phenomena [ˈɔptikəl - fiˈnɔminə] n. 光学现象
- rainbow [ˈreinbəu] n.彩虹
- halo [ˈheiləu] n. 日晕
- strike [straik] v. 照在……上
- raindrop [ˈreindrɔp] n. 雨滴
- cumulonimbus [ˈkju:mjuləuˈnimbəs] n.积雨云
- prism [ˈprizəm] n. 棱镜
- bend [bend] v. 使弯曲
- reflect [riˈflekt] v. 反射
- angle [ˈæŋɡl] n. 角，角度
- band [bænd] n. (光、频)带，(波)段
- cirrostratus [ˈsirəuˈstrɑ:təs] n.卷层云
