Explain why cyclones weaken over land and why air pressure decreases with altitude.

B. Lack of moisture supply Cyclones derive their energy from the evaporation of warm ocean water, which provides latent heat. When a cyclone moves over land, it loses this continuous supply of moisture and latent heat, causing it to weaken.

B. Density of air decreases As altitude increases, the amount of air molecules above a given point decreases. This results in fewer air molecules in a given volume, meaning the air becomes less dense. Since air pressure is the force exerted by the weight of the air column above, a decrease in air density leads to a decrease in air pressure.