At the equator there is an area of ____ pressure, due to the rising and expanding air.

• A. High
• B. Low
• C. Normal
• D. Variable

Answer: (B)

Rising and expanding air at the equator reduces the amount of air near the surface, creating a belt of low pressure there. When air is strongly heated at the surface, it becomes buoyant and climbs upward; as it rises into the cooler atmosphere, it expands and cools, reinforcing the upward motion and keeping surface pressure lower than in surrounding regions. This low-pressure area is linked to the ITCZ, where frequent rainfall and cloudiness occur due to the intense convection. High pressure would come from sinking air and is typical of other regions, not the equator. Normal pressure is just the average, and variable pressure would imply inconsistent readings, which doesn’t capture the persistent equatorial low driven by heating and convection. So the equator is characterized by low pressure.