Question

How does the unequal heating of Earth’s surface cause winds?

Answer 1

Hint: The occurrence of winds on the surface of Earth is a consequence of the process of convection in heat transfer. Major weather changes and climatic conditions at a geographical location is a direct impact of the wind and thus, convection.

Complete answer:
The term wind is applied to the bulk movement of air from a region of higher pressure to lower pressure of air. This happens due to a mode of heat transfer known as convection.
A region of air column in a geographical location gets heated up due to the sun. The temperature of the air rises. This leads to an increase in the density of air at the region and thus, the air rises above the Earth’s surface. This increase of the air leads to the formation of a region of low pressure. To compensate this, the air from the surrounding region flows in the region, thereby causing bulk movement of air known as wind.
If the Sun were to heat the surface of the entire Earth uniformly, this phenomenon of wind formation would not take place. But that is not the case, since different latitudes of Earth receive different kinds of heat from the sun.
The rays of the Sun are directly pointed at the right angle with straight rays in the equatorial region. As the latitude increases, the rays of sun start slanting. Thus, higher latitudes receive slant rays of Sun. This means that the equatorial regions get heated more than the higher latitudes, as demonstrated below –
This unequal heating of Earth’s surface where the equatorial regions receive more heat compared to the higher latitudes, result in global winds known as trade winds and westerlies.

Note: The unequal heating of Earth’s surface is a consequence of the fact that the Earth’s axis is not straight. The axis of Earth is inclined at an angle of $23.{5^ \circ }$. Had the axis of Earth been straight, all the regions of the Earth would receive equal heat and thus, eliminate the formation of winds, which results in serious disasters in the climatic conditions of Earth.