Question

Typical United States weather patterns show the continental polar air mass moving south toward the Gulf of Mexico. Why does this air mass movement happen?
A) Colder air masses move from north to south.
B) Continental air masses always move in the direct of the nearest body of water.
C) The polar air mass moves south to replace the rising maritime tropical air mass.
D) The continental polar air mass is blocked in by maritime air masses on all sides.

Answer 1

Continental Polar air masses form over Canada and Siberia. These air masses bring cold air during the winter and cool, relatively clear, rather pleasant weather in the summer. The air mass is stable and usually prevents cloud formation. It also can develop inversions which inhibits vertical motion and may cause high pollution events, especially near and downwind of large industrial areas. As the Continental Polar air move south across the warmer land, the lower portion of the air mass may become sufficiently modified by warming to cause a few clouds to form within the air mass.

Answer 2

I would say C, because the maritime tropical air mass is most often felt in the Southeast US. In the winter this air mass is shoved toward the equator but in summer it can cover much of the US east of the Rockies.