Question

At the coast on a summer day, the land is hotter than the ocean. Warm air over the land rises and is replaced by cooler air, causing a sea breeze. At night, the land cools quickly and the ocean is now warmer than the land. What will happen next? a)Winds will stop blowing as the convection current ceases to flow.

b)The convection current will reverse direction, reversing the winds.
c)Winds will increase as the two convection currents overlap.
d) The convection current will move seaward, reversing the winds.

Answer 1

b)The convection current will reverse direction, reversing the winds.

Step-by-step explanation:

Sea breeze is caused by the fact that the land is able to get warmer/cooler quicker than the water in the sea, due to the very high specific heat capacity of the water. For this reason:

- during the day, the land gets warm quicker than the water. The land, therefore, release heat into the air over it, which becomes warm. The air over the sea, on the contrary, is still cold (since the water takes more time to get warm), so a convection current occurs, in which the warm air over the land flows towards the sea, and it is replaced by the cold air coming from the sea.

- during the night, the process is reverted: the land gets cold quicker than the water. Therefore, the air over the sea is warmer than the air over the land. So a convection current occurs, but in this case the warm air over the sea flows towards the land, and it is replaced by the cold air coming from the land.

Therefore, the correct choice is

b)The convection current will reverse direction, reversing the winds.