A parcel of air at the surface is heated which expands the air and increases the parcel's volume. If the same number of air molecules occupy the greater volume, density decreases. The increase in volume results in lower pressure.

The surrounding air will move towards the area of less density.

Explanation:

As the complete question is not presented, the complete question is attached with the solution.

As the air pressure is reduced in the area, the density is reduced. The surrounding area will have air at the higher density or at higher pressure. Due to this imbalance between two pressures, the air will flow from the higher pressure to the lower pressure such that the equilibrium is achieved.