In coastal towns, breezes tend to blow offshore (from the land to the ocean) during the night and early morning, and onshore (from the ocean to the land) during the afternoon and evening. What factors primarily contribute to this effect?
It can be more than one answer!
A.Heat conduction
B.Heat convection
C.Specific heat of land vs water
D.Salinity of the water
E.Thermal expansion
B for sure. In afternoon land hot, air rises there. Wind moves ashore from over ocean to replace it.
C causes land to warm up fast, water takes a lot of heat to warm up much, stays about the same temp. Thus certainly C
E yes for air. As it heats up over land it expands and therefore density goes down and it rises, so yes E
The primary factors that contribute to the onshore and offshore breezes in coastal towns are heat convection, specific heat of land vs water, and thermal expansion.
To understand why this happens, let's break down each factor:
A. Heat convection: During the day, the land heats up more quickly than the water due to its lower specific heat capacity. This difference in temperature causes air to rise above the land and creates a low-pressure region. As a result, air from the cooler ocean rushes in to fill this void, resulting in the onshore breeze.
B. Specific heat of land vs water: Water has a higher specific heat capacity than land. This means that water takes longer to heat up and cool down compared to land. During the day, land heats up more rapidly than water, creating a temperature difference between the two. This temperature difference contributes to the formation of breezes as mentioned earlier.
C. Thermal expansion: When water is heated, it undergoes thermal expansion, meaning it expands in volume. This expansion causes the water near the coast to become slightly warmer than the water further offshore. The temperature difference between the warmer coastal water and the cooler offshore water also contributes to the formation of the onshore breeze.
Factors D (salinity of the water) and E (thermal expansion) do not directly play a primary role in the formation of the onshore and offshore breezes. The salinity of the water might affect the specific heat capacity of the water slightly, but it is not a primary factor in this phenomenon. Similarly, thermal expansion plays a role in creating the temperature difference near the coast, but it is primarily due to the specific heat capacity difference between the land and water.
So, the correct answers would be B (heat convection), C (specific heat of land vs water), and E (thermal expansion).