Air mass is a large body of air with similar properties all through it.
Describe the four common air masses and where they are found: maritime polar air, continental polar air, maritime tropical air, and continental tropical air.
Maritime polar air masses form in the ocean near the poles, and are cold and moist. Continental polar air masses form over land near the poles, and are cold and fairly dry. Maritime tropical air masses form over tropical oceans or rainforests and are warm and very humid. Continental Tropical Air masses form over hot desserts and are warm and fairly dry.