What directly causes the pressure difference between the equator and the poles?
• the amount of heat in each area
• the length of each season
• the rotation of Earth on its axis
• the direction where wind blows
The rotation of Earth on its axis causes the pressure difference between the equator and the poles.
The pressure difference between the equator and the poles is primarily caused by the amount of heat in each area. Here's why:
1. Temperature: The equator receives more direct sunlight throughout the year compared to the poles. This excess heat causes the air at the equator to warm up and expand, creating a region of low pressure. In contrast, the poles receive less sunlight, which leads to colder temperatures and denser, high-pressure air.
2. Air Circulation: Warm air rises at the equator, creating a low-pressure region. As the warm air ascends, it cools and begins to move towards the poles. This movement forms a global circulation pattern called the Hadley Cell, where air flows from the equator towards the poles at high altitudes.
3. Coriolis Effect: The rotation of the Earth on its axis also contributes to the pressure difference. Due to the Coriolis effect, the Earth's rotation causes the air moving from the equator towards the poles to be deflected to the east in the Northern Hemisphere and to the west in the Southern Hemisphere. This deflection leads to the formation of prevailing winds such as the trade winds and westerlies.
4. Wind Patterns: The direction where wind blows is a consequence of the pressure differences between the equator and the poles. Air flows from regions of high pressure to regions of low pressure. As a result, winds blow from the poles to the equator near the surface, which are known as polar winds or polar easterlies.
In summary, while factors like the length of each season and the direction where wind blows are influenced by the pressure difference, the primary cause of the pressure difference between the equator and the poles is the amount of heat in each area.