大気が

the atmosphere

→ 大気
phrase Rare #36,282
the atmosphere 大気 means “atmosphere” or “air,” and が marks it as the subject of the sentence. The phrase is usually followed by more information about the atmosphere.
JA: 大気が少しずつ変化している。
EN: The atmosphere is gradually changing.

大気が排気ガス汚染された

The atmosphere was polluted by exhaust fumes.

大気が

The atmosphere…

— 風の谷のナウシカ (1984)

大気が怒りに満ちておる

The air is filled with anger.

— 風の谷のナウシカ (1984)

大気が地球包んでいる

The atmosphere surrounds the Earth.