Which term describes the area where an air mass originated?

Which term describes the area where an air mass originated?

• A. Front
• B. Source region
• C. Boundary
• D. Formation zone

Answer: (B)

The area where an air mass originates is called the source region. This is the place where the air mass sits long enough over a surface—sea or land—with relatively uniform conditions, so it takes on characteristic temperature and moisture properties. That origin sets whether the air mass is, for example, warm and moist or cold and dry. A front, by contrast, is a moving boundary between air masses with different properties, not where they began. The term boundary is a general idea for that interface, and formation zone isn’t a standard meteorology term. So the origin area best describes how the air mass gets its defining traits.

The area where an air mass originates is called the source region. This is the place where the air mass sits long enough over a surface—sea or land—with relatively uniform conditions, so it takes on characteristic temperature and moisture properties. That origin sets whether the air mass is, for example, warm and moist or cold and dry. A front, by contrast, is a moving boundary between air masses with different properties, not where they began. The term boundary is a general idea for that interface, and formation zone isn’t a standard meteorology term. So the origin area best describes how the air mass gets its defining traits.