Earth's Rotational Axis

• The Earth does not spin like a toy top, but spins at a rotational tilt of 23.5 degrees. This tilt affects the temperatures across the globe, creating the seasons. As the Earth rotates with the tilt angled toward the sun, the hemisphere closer to the sun receives stronger rays, generating a summer season. In contrast, the hemisphere tilting away from the sun's rays has winter-like conditions.
  
  

Sun's Influence

• The Earth's rotational tilt explains the seasonal temperature fluctuations affecting air heating and cooling. However, the influence of the sun creates the overall unequal heating of the air. The sun's rays intensely heat the water in the Equator region. The ocean water warms and evaporates into the air. The warm air reaches the top portion of the Earth's atmosphere, called the troposphere. The air cannot rise any further, eventually spreading north and south toward the Earth's poles. The air slowly cools as it travels north and south, eventually sinking down through the atmosphere.
  
  

Wind Patterns

• The Earth would not have wind patterns without the sun's unequal heating of the air. The rising warm air produces a low pressure area beneath it. The cold, sinking air generates a high-pressure area. Air naturally flows from a high-pressure region to a low-pressure region. The natural air flow creates the trade winds at the Equator, as well as the westerly winds produced in the southern and northern hemispheres.
  
  

Land Influences

• Many of the Earth's deserts reside in the regions with high-pressure influences from the unequal air heating. The cooler air that sinks creates dry conditions within the high-pressure region. The Sahara and Sonoran deserts were generated from this air influence. The low-pressure regions produced from the rising warm air generate humid and wet land areas. Land along the Equator, such as the Amazon jungle, benefits from warm and rainy weather, creating lush plants and multiple animal species' habitats.
  
  

Wind Pattern Movement

• Along with the sun, the Earth's rotation generates a meeting of the westerly and trade winds. The unequal air heating moves the two wind patterns in opposite directions. However, the Coriolis Effect, or curved wind patterns, caused by the Earth's rotation forces the wind patterns to move counter-clockwise in the southern hemisphere and clockwise in the northern hemisphere.