What term describes an air mass that develops over water?

The term that describes an air mass that develops over water is maritime. Maritime air masses are characterized by their moisture content, as they originate over oceans or large bodies of water. These air masses tend to bring higher humidity levels and can lead to increased precipitation when they move over land, influencing climate and weather patterns.

The other terms refer to different characteristics of air masses. Tropical air masses originate in warm regions, typically near the equator, and can bring warm weather but are not specifically tied to moisture content from water. Polar air masses form in cold regions near the poles and are associated with colder weather. Continental air masses, on the other hand, develop over land and tend to be dry because they lack the moisture provided by large bodies of water. Understanding these distinctions helps to predict weather patterns and the impact of various air masses on local conditions.