1. 大气;大气层;大气圈
    A planet's atmosphere is the layer of air or other gases around it.

    e.g. ...dangerous levels of pollution in the Earth's atmosphere...
           地球大气层污染程度严重
    e.g. The Partial Test-Ban Treaty bans nuclear testing in the atmosphere.
           《部分禁止核试验条约》禁止在大气层中进行核试验。

2. （呼吸的）空气
    The atmosphere of a place is the air that you breathe there.

    e.g. These gases pollute the atmosphere of towns and cities.
           这些气体污染了城镇的空气。

3. 氛围；环境
    The atmosphere of a place is the general impression that you get of it.

    e.g. Pale wooden floors and plenty of natural light add to the relaxed atmosphere...
           淡色木地板和充足的自然光平添了几分轻松的氛围。
    e.g. There's still an atmosphere of great hostility and tension in the city.
           强烈的敌对和紧张气氛依然笼罩着这座城市。

4. （地方或事件的）情调，魅力
    If a place or an event has atmosphere, it is interesting.

    e.g. The old harbour is still full of atmosphere and well worth visiting.
           这座古老的港口依然充满了情趣，颇值得一游。