What is a characteristic feature of a stable air mass?

A stable air mass is defined by its ability to resist vertical air movement, which is a fundamental characteristic that affects weather patterns and climate. In a stable environment, air parcels that are forced to rise will cool, becoming denser than the surrounding air, and will tend to sink back to their original position. This resistance to vertical motion often results in limited cloud formation and can lead to clear skies.

While the other characteristics mentioned are associated with different atmospheric scenarios, they do not define stability. For example, vertical air motion is typically promoted in unstable air masses where rising motion can lead to cloud development and even storms. Temperature and moisture content are factors that can vary widely in stable air; a stable air mass is not necessarily cold or moist, as it can also be warm and dry, depending on its source region. The key point is that stability is primarily characterized by the air mass's resistance to vertical movement, making it less conducive to dramatic weather changes.