air mass

noun

1. a body of air covering a relatively wide area, exhibiting approximately uniform properties through any horizontal section.

air mass

noun

1. a large body of air having characteristics of temperature, moisture, and pressure that are approximately uniform horizontally

air mass

1. A widespread body of air that originates over a large area of land or ocean and assumes the temperature and humidity of that area, with characteristics distributed fairly evenly throughout the horizontal layers of the mass. Air that stands over the Caribbean Sea, for example, becomes a warm, humid maritime tropical air mass, while air that lies in the Arctic regions of northern Canada takes on the cold and dry characteristics of its surroundings and becomes a continental polar air mass. When air masses of differing properties come into contact in the middle latitudes, they frequently generate storm fronts.

Word History and Origins

Origin of air mass¹

First recorded in 1890–95

Example Sentences

The weather will start to cool down on Saturday as a cold front pushes southwards, with the air turning progressively colder into next week as an Arctic air mass becomes established.

From BBC

A weather front crossing the UK on Sunday will bring a change in air mass.

From BBC

A relatively stable air mass blows from southwest to northeast over the Transverse Ranges north of L.A.

From Los Angeles Times

He said they’re the sort of air masses often associated with desert conditions — and with a particular jet stream pattern called an “omega block” because of its shape.

From Los Angeles Times

Once at that altitude, the chemicals can have far-reaching climate impacts because air in the stratosphere spreads out globally and remains for months to years, unlike the lower atmosphere where air masses turn over weekly.

From Science Daily