What air masses originate over water?
Besides, how do air masses originate?
An air mass forms whenever the atmosphere remains in contact with a large, relatively uniform land or sea surface for a time sufficiently long to acquire the temperature and moisture properties of that surface. The Earth's major air masses originate in polar or subtropical latitudes.
Hereof, what do maritime air masses originate over?
Maritime tropical air masses originate over the warm waters of the tropics and Gulf of Mexico, where heat and moisture are transferred to the overlying air from the waters below. The northward movement of tropical air masses transports warm moist air into the United States, increasing the potential for precipitation.
Four major types of air masses influence the weather in North America: maritime tropical, continental tropical, maritime polar, and continental polar.