の空気は

the air in

→ の
phrase Uncommon #14,571
the air in の connects a place or area to 空気 (air), and は marks the phrase as the topic. Depending on context, it can also mean “the air of.”
JA: この町の空気はとてもきれいです。
EN: The air in this town is very clean.

シドニーの空気は東京よりきれいです

The air in Sydney is cleaner than in Tokyo.

海辺の空気はきれい健康的

The air by the sea is clean and healthy.

の空気は気持ちいい

The morning air feels refreshing.

ここの空気はひどいな

The air in here is awful.

ロンドンの空気はどうよくみて大して自慢できるものでなかった

Even at its best, London's air was nothing much to boast about.

この土地の空気は私の性に合わない

The atmosphere here doesn't suit me.

この部屋の空気は汚れている

The air in this room is polluted.

シドニーの空気は東京空気よりきれいです

The air in Sydney is cleaner than the air in Tokyo.

の空気は新鮮心地よい

The morning air is fresh and pleasant.

ここの空気は澄んでいるんだよ

The air here is crystal clear.

— 風の谷のナウシカ (1984)

の空気はすばらしい

The mountain air is wonderful.

シャバの空気は?

How's the air out here in the real world?

— アメリカン・ギャングスター (2007)

この辺の空気はきれいです

The air around here is clean.