Our planet needs about 365 days to orbit the sun in an elliptical path, which we celebrate every year. In the meantime, the Earth constantly rotates on its own axis. The average duration of one revolution lasts about 24 hours. The Earth’s rotation is, therefore, responsible for the day-night cycle. So, how are seasons formed, and what causes one place on Earth to be rainy and the other location to be painfully hot?
The reason for the origin of the seasons is the inclination angle (23.5 °) of the Earth. The axis of rotation is not perpendicular to the orbital plane, or the equator is not horizontal to the sun. As a result, the sun does not shine evenly in different parts of the world.
When the northern hemisphere is inclined towards the sun, the sun’s rays hit the Earth there at a steeper angle. At this point, it’s summer in the northern hemisphere, and winter is prevalent in the southern hemisphere. When the southern hemisphere is inclined to the sun, and the angle of incidence of the sun rays is higher.
The steeper the angle of incidence, the higher the radiation energy of the sun. Some assume that the seasons arise due to the changing distance between the sun and the Earth, which is not the case because, in winters, the distance between the sun and the Earth is even less than in summer.
If the angle of inclination of the Earth was 0 °, i.e., the axis of rotation was perpendicular to the orbital plane, or the equator was horizontal to the sun, we would have roughly the same climate and no different seasons throughout the year since the angle of incidence of the sun rays would remain the same all year round.
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We, humans, combine the seasons very strongly with the appearance of nature, which is very typical for us in every season. The first buds and leaves emerge in spring, and the climate is still mild. Summer is characterized by warm temperatures.
Trees bear fruit, and the growth of the plants is strongest. In autumn, the leaves gradually turn yellowish-brown until they finally fall off. The temperatures are now much milder. Winter is the coldest season, and snow occasionally covers the landscape.
Every year in June, the summer starts with the longest day of the year, the summer solstice. It is the time when the sun is perpendicular to the tropic, and the days are longest. In the northern hemisphere, the summer solstice happens every year on June 21. In the southern hemisphere, however, the day falls on December 21.
Exactly the opposite happens in the south of the equator. When we start our summer in the northern hemisphere, winter begins in the southern hemisphere.
This is because the North Pole is pointing towards the sun at this time, while the South Pole is inevitably pointed away from it. This happens because the Earth’s orbit is not circular, but slightly elliptical, our seasons are not all the same length.
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Conclusion – How Are Seasons Formed
The angle of inclination of the Earth which is 23.5 °, is responsible for causing the seasons. It is because the northern hemisphere is once inclined towards the sun, causing summer then once shy away from the sun causing the winter during the course of the year.
The steeper the sun’s rays hit the Earth called the angle of incidence, the higher the radiation energy released by the sun, causing warmer temperatures in the hemisphere. So now you know How Are Seasons Formed. Next time the season changes, you would know the position of Earth in our little solar system.