What relative humidity characterizes the Tropical Continental (cT) air mass?

• A. High
• B. Moderate
• C. Low
• D. Very Low

Answer: (C)

The air mass is formed over hot tropical land, where intense heating makes the air very warm but the surface moisture sources are limited. Relative humidity compares how much water vapor is actually in the air to how much the air could hold at that temperature. Warm air can hold a lot of moisture, but because tropical continental air masses come from dry land with little moisture available, the actual amount of water vapor is low. The result is a low relative humidity, reflecting dry, sunny conditions that come with cT air. High or moderate humidity would require more moisture in the air, typically from oceans, while very low humidity would be extremely dry beyond the usual tropical continental pattern. So, tropical continental air masses are characterized by low relative humidity.