What term describes the boundary between two air masses with different temperatures?

• A. Jet stream
• B. Front
• C. Boundary
• D. Air boundary

Answer: (B)

In meteorology, the boundary between two air masses that have different temperatures is called a front. This boundary forms where air masses with contrasting temperatures (and often humidity) meet but don’t mix readily. The temperature contrast causes the warmer air to lift over the cooler air, which promotes cloud formation and can bring precipitation.

There are several types depending on which air mass is advancing: a cold front occurs as colder air pushes in under warmer air; a warm front forms when warmer air slides over retreating cooler air; a stationary front is when neither air mass moves significantly; and an occluded front happens when a cold front catches up to a warm front. Other terms, like jet stream or generic boundaries, don’t specifically name this meteorological boundary.