Antarctic air mass
Technical term in meteorology referring to a large body of air originating over Antarctica, characterized by very cold and dry properties.
When an Antarctic air mass moves northward, temperatures in the Southern Hemisphere can drop sharply.
寒気団 is a general term for a cold air mass, while 南極気団 specifically refers to one originating from Antarctica.
気団 is the broader term for any air mass; 南極気団 is a specific type.
Compound of 南極 (Antarctic) + 気団 (air mass).