Cadet Competition Written Practice Exam

What is the fundamental cause of the Earth's various weather conditions?

1. The moon's gravitational pull

2. The sun heats the Earth

3. The rotation of the Earth

4. The position of the continents

The correct answer is: The sun heats the Earth

The fundamental cause of the Earth's various weather conditions is primarily due to the sun heating the Earth. The sun's energy drives the climate system, influencing temperature, air pressure, and humidity, which are crucial factors in weather formation. When the sun’s rays hit the Earth, they are absorbed by land and water, warming the surface. This uneven heating—because of factors such as the angle of sunlight, the Earth's tilt, and the varying characteristics of land and water—creates differences in temperature and pressure. These differences in turn lead to air movement (wind) and the development of weather patterns. Additionally, while the rotation of the Earth and the position of the continents do have significant effects on specific weather phenomena and climate patterns, the initial and primary driver of weather variability is the sun's energy. The moon's gravitational pull influences tides but does not have a direct role in the daily variations in weather. Thus, the most fundamental cause linking to various weather conditions remains the sun's heating effect on the Earth.