Sea Breezes and Land Breezes - Class 7 Science explained - CBSE Class Notes Online

Convection and Its Role in Sea Breeze and Land Breeze

Sea breezes and land breezes are natural phenomena that occur near coastlines due to the process of convection.
Convection is the transfer of heat through the movement of fluids (such as air or water) caused by differences in temperature.

During the day, the land heats up faster than the adjacent water (sea or ocean). Land absorbs solar radiation more effectively.
As the land gets hotter, it warms the air just above it.
Hot air is lighter and less dense, causing it to rise. This rising air creates an area of low pressure over the land.

Cooler, denser air from the sea rushes in to replace the rising warm air over the land.
This movement of air from the sea toward the land is known as a “sea breeze.”
The incoming sea breeze brings cooler air from the water, providing relief from the daytime heat near the coast.

At night, the land cools down more quickly than the water because it radiates heat into the atmosphere.
As a result, the air over the land becomes cooler and denser.
Cooler, denser air is heavier and creates a higher pressure area over the land.

The warmer air over the water now moves towards the cooler, higher-pressure land area, forming a “land breeze.”
This land breeze carries heat away from the land, resulting in cooler nighttime temperatures near the coast.

Convection plays a vital role in the formation of sea breezes and land breezes.
During the day, the heating of the land causes warm air to rise, drawing in cooler air from the sea, leading to a sea breeze.
At night, as the land cools faster than the water, the reverse occurs, with cooler, denser air from the land moving towards the warmer sea, forming a land breeze.
These natural phenomena are important for coastal climates, influencing temperature variations and providing relief from extreme temperatures.