During spring, warm air moves north and mixes with cold air remaining from winter.

VOA: special.2009.06.09

Warm air rising from below causes the wind tube to reach toward the ground.

VOA: special.2010.05.11

He could feel the warm, sweet air inside.

VOA: special.2009.04.04

But inside, the air was warm and sweet.

VOA: special.2009.04.11