What happens when land cools quicker than the sea?
After the sun sets, land typically cools more rapidly than the ocean or sea. As the land cools, the air close to the surface cools, as well. Since cold air is denser than warm air, the cold air tends to sink and compress. The falling and compressing air creates a void at higher altitudes, and the void is then filled with high-altitude air over the oceans or sea. This, in turn, creates an updraft of air over the water, which creates a void at low altitude over the water. Finally, the air near the land's surface tries to fill the void over the water. This produces on offshore breeze or a land breeze. That is, the wind blows away from land and out to sea. The reverse occurs when the sun rises and heats the land faster than the water.