What is the defining characteristic of Maritime Equatorial (mE) air masses?

The defining characteristic of Maritime Equatorial (mE) air masses is that they consist of hot and humid air originating from regions close to the equator. These air masses form over warm tropical oceans, where they gain significant moisture through evaporation. As they move over land or interact with other air masses, they can lead to the formation of clouds and precipitation due to their high humidity content.

The association with the equatorial region also means that these air masses are typically warm because they are influenced by consistent, direct sunlight throughout the year. This combination of warmth and moisture plays a critical role in weather patterns, particularly in tropical climates, where heavy rainfall and thunderstorms are common when mE air masses are present.

In contrast, the other options represent different types of air masses with distinct characteristics that do not align with the properties of Maritime Equatorial air. Cold and dry air from the poles describes polar air masses, while cool and moist air from oceanic regions relates to maritime polar (mP) air. Lastly, warm and dry air from continental interiors refers to continental air masses, which do not have the high humidity characteristic of mE air masses.