Which air mass is warm and moist and originates from tropical oceans?

• A. cT
• B. mT
• C. cP
• D. mP

Answer: (B)

Air masses are defined by where they form and their moisture and temperature characteristics. A warm, moist air mass that forms over tropical oceans is maritime tropical. The word maritime means it develops over water, giving it high humidity, while tropical means it’s heated by the sun in the tropical region, so the air is warm. This combination makes it hot and humid, often bringing muggy weather and thunderstorms when it moves into other regions.

This fits best with a maritime tropical air mass. By contrast, continental tropical would be hot and dry, forming over land in tropical areas; maritime polar would be cool and moist, coming from cooler oceans in higher latitudes; continental polar would be cold and dry, from cold continental regions.