Question

The existence of convection heat transfer has been long used by traditional fishermen for fishing purposes. For example, by utilizing land breeze, the fishermen will go to the sea at night, and conversely, by utilizing sea breeze they will come back during the day. How this natural heat transfer can be used by the fishermen? Next, explain the mechanism of the occurrence of the land breeze and the sea breeze and their relation to the convection heat transfer events in detail along with the sketches.

Answer 1

This natural heat transfer can be used by fishermen to preserve their fish from getting decayed faster. They can preserve the fish by understanding the natural temp, oxidation and the optimum conditions when when the bacteria will be least active and eventually modifying these conditions to achieve preservation.

Hot air rises due to expansion of air as it warms up and it is easier to expand upwards because of the lower air pressure above. This results in convection heat transfer.

During a sunny day, in general, the land warms up more quickly than the sea. The convection of air above the ground is therefore greater than above the sea. This results in low air pressure above the ground than above the sea. In this situation, air moves from the sea to the land and is called sea breeze.

Conversely, at night time, the land cools more quickly than the sea and the reverse happens, the relatively cooler air above the land becomes more dense than the air above the sea, resulting in a gradual movement of air from land to sea, effectively pushing warmer sea air upwards. This is called land breeze.