In a strongly heated area, what happens to the surface air pressure and why?

Temperature and pressure in the lower atmosphere are closely linked through the density of air. When air near the surface becomes very warm, its molecules move faster, the air expands, and its density decreases. A lighter column of air exerts less weight on the ground, so the surface pressure is reduced in that region.

In a strongly heated area, a parcel of air becomes warm, expands, and rises away from the surface. As this air moves upward, some mass is removed from the column of air directly above the ground. Because less air remains in that column, the pressure measured at the surface must decrease, which is why the correct option states that pressure falls as heated air rises.

Options A and B wrongly assume that warm air is heavier or that it piles up near the ground to increase pressure. In reality, warm air is lighter, not denser, so it does not press more strongly on the surface. Option D is also incorrect because changes in temperature are one of the main physical reasons for changes in air pressure in basic climatology, especially near the surface.

For UPSC questions, always connect pressure zones with vertical air movement as well as temperature. Heated, rising air is typically linked to low pressure and can favour cloud formation, while cooler, sinking air is linked to higher pressure and generally clearer skies. Remember this pattern when solving questions on monsoon, cyclones, and global wind belts.