Continental arctic air mass
Also called: cA · Topic: Air Masses, Fronts, Cyclones and Thunderstorms · NCERT: Class 11, Ch 9 "Atmospheric Circulation and Weather Systems"
Meaning
A continental arctic (cA) air mass is the coldest and driest type of air mass. It forms over the permanent ice of the Arctic and Antarctica. The air rests for a long time on ice that never melts, so it becomes extremely cold and holds almost no moisture. When it breaks out towards the middle latitudes, it brings severe cold spells.
Example
In some winters, arctic air from the frozen Arctic Ocean pours south across northern Canada into the Great Plains of the United States. Temperatures there then drop sharply within a day or two.
Don't confuse with
- Continental polar (cP) air mass: cP air forms over snow-covered land in high latitudes, such as Siberia and northern Canada. It is cold and dry, but less extreme than cA air, which forms over permanent ice.
Related concepts
- Air mass
- Source region
- Maritime tropical air mass
- Continental tropical air mass
- Maritime polar air mass
- Continental polar air mass