Which air mass is hot and dry and originates from subtropical continents?

• A. cT
• B. mT
• C. cP
• D. mP

Answer: (A)

Air masses are categorized by where they form and their typical moisture and temperature. A hot, dry air mass that forms over dry subtropical lands is the continental tropical air mass. The subtropics consist of arid or semi-arid regions, so the air there is heated strongly at the surface and contains little moisture, producing high temperatures with low humidity. That combination—very warm to hot and dry—defines continental tropical.

For contrast, maritime tropical would be hot and humid because it forms over warm tropical oceans; continental polar and maritime polar are associated with cold or cool conditions and varying moisture depending on the region, not hot and dry from subtropical continents.