1. Earth's Axis Tilt: The Earth's axis is tilted on an angle of approximately 23.4 degrees relative to the plane of its orbit around the Sun. This tilt plays a crucial role in determining the seasons.
2. Earth's Orbit around the Sun: The Earth's orbit around the Sun is an elliptical path, but for simplicity's sake, we can assume it's a circular path. As the Earth moves along its orbit, different parts of the Earth are tilted either toward or away from the Sun at different times of the year.
3. Summer and Winter Solstices: The summer and winter solstices are the two most important points in the Earth's orbit. The summer solstice occurs when the Northern Hemisphere is tilted the most toward the Sun, while the winter solstice occurs when the Northern Hemisphere is tilted the farthest away from the Sun.
a) Summer Solstice (June): During the summer solstice, the Northern Hemisphere is tilted toward the Sun, resulting in longer days and shorter nights. The Sun reaches its highest point in the sky during this time.
b) Winter Solstice (December): During the winter solstice, the Northern Hemisphere is tilted away from the Sun, leading to shorter days and longer nights. The Sun appears to be at its lowest point in the sky during this time.
4. Changing Angles of Sunlight: As the Earth orbits the Sun and the tilt of its axis changes, different parts of the planet receive varying amounts of direct sunlight at different times of the year.
a) Summer: In the Northern Hemisphere, the tilt toward the Sun in summer means that direct sunlight strikes the ground at a higher angle, resulting in more intense and longer daylight hours. This is why summer months are generally warmer.
b) Winter: In winter, the tilt away from the Sun causes direct sunlight to strike the ground at a lower angle, leading to less intense and shorter daylight hours. This, combined with longer nights, leads to colder temperatures.
5. Seasonal Variations in Climate: The changing angles of sunlight and variations in daylight hours cause seasonal changes in weather patterns, temperatures, precipitation, and vegetation growth in different parts of the world. These variations give rise to distinct seasons like spring, summer, autumn, and winter.
In summary, the seasons are caused by the tilt of the Earth's axis as it orbits the Sun. As different parts of the planet receive varying amounts of direct sunlight throughout the year, they experience different seasonal changes in climate and weather patterns.