What is defined as a large body of air with uniform temperature and humidity characteristics?

The concept of an air mass refers to a large volume of the atmosphere that maintains consistent temperature and humidity. This uniformity arises because an air mass typically forms over vast regions, either over land or water, where it acquires characteristics that influence its properties.

Air masses are classified based on their source regions—continental or maritime, and polar or tropical. For example, a maritime tropical air mass originates over warm ocean waters and is associated with warm, humid conditions, while a continental polar air mass arises over cold land areas and tends to be colder and drier. Understanding air masses is crucial in meteorology as they play a significant role in weather patterns and climate, ultimately influencing precipitation, temperature, and general weather conditions in different regions.

Other options provided do not encapsulate the same definition. A weather system typically refers to a localized phenomenon or event, like a storm, while an atmospheric front denotes the boundary between two differing air masses. A pressure system relates to areas of high or low atmospheric pressure but does not specifically denote temperature and humidity characteristics.