The wind is defined as air in motion and it has speed and direction. In other words, the wind is the horizontal flow or movement of air masses on the earth’s surface. Wind ranges from simple, light and comfort breeze to chaotic and destructive hurricane.
Factors affecting wind
- Rotation of the earth – owing to rotation of the earth, winds are deflected to the right in the northern hemisphere and to the left, in the southern hemisphere. This is often referred to as Ferrell’s Law of Deflection.
- Temperature – it is also known that high temperature creates low pressure in areas where such temperature occurs. When the air above the ground surface gets heated, it expands and rises since it has become light. The surrounding air, which is denser than the heated air, then moves in to take the place of the ascending air.
- Pressure – owing to differences in the rate of temperature in various areas which either create high-pressure belt (low temperature) or low-pressure belt (high temperature), it is known that winds, therefore, tend to blow from the high-pressure belts to the low-pressure belts.
Winds blow from the subtropical high-pressure belt in the northern hemisphere towards the equatorial low-pressure belt to become North-East Trade Winds while those blowing from the Southern hemisphere become the South-East Trade Winds.