This article discusses about the Summer and Winter Solstice of the Earth, its position related to the sun, the cause of the solstice and also the time during which we experience these two solstice in both the Hemispheres
Summer and Winter Solstice: The earth revolves around the Sun, in an elliptical orbit with a 22 ½ degree tilt on its axis. This mechanism allows the northern hemisphere to receive more amount of sunlight during the summer than the southern hemisphere. The length of days are usually longer in summer than the winter. This is primarily because the Sun rises earlier in the morning and sets late.
When the Northern Hemisphere is tilted towards the Sun, people living north of the equator (India, China, Europe, North America) experience Summer and longer days. While the people South of the equator experience Winter and shorter days. Similarly when the earth’s Southern Hemisphere is tilted towards the Sun, natives living south of the Equator (South America, Australia, New Zealand) experience Summer while it is Winter in the Northern Hemisphere.
Figure 1: Showing the Position of the Earth in the different solstices
What is Winter Solstice?
The Winter Solstice as discussed marks the shortest day of the year when the amount of sunlight received is the least. This varies according to the Hemisphere. In Northern Hemisphere, during 21st or 22nd December the Sun is vertically overhead the Tropic of Capricorn.
While for people who live in the Southern Countries like Australia, Chile, southern Brazil, and South Africa, their Winter Solstice occurs during 21st or 22nd June, when the sun is directly over the Tropic of Cancer.
What is Summer Solstice?
The Summer Solstice like the Winter Solstice varies according to the Hemisphere. In the North of Equator, the date of Summer Solstice is usually on June 21st where the Sun is vertically over the Tropic of Cancer and people experience the longest days. The Summer Solstice in the Southern Hemisphere occurs during December when their days are the longest with the sun over the Tropic of Capricorn.
Figure 2: Showing the different positions of Earth on its orbit
Difference between Summer and Winter Solstice
The day of a solstice in either hemisphere has either the maximum amount of sunlight of the year (summer solstice) and marks the beginning of Summer or Winter. The Summer Solstice in Northern Hemisphere is also referred to as the June Solstice because it occurs on 21st or 22nd June. The least sunlight of the year (winter solstice) occurs during December 21st or 22nd.
The Summer Solstice in the Southern Hemisphere, on the other hand, occurs on December 21st or 22nd and people experience the longest day below the Equator. The Winter Solstice is also reversed and occurs on either the 21st or 22nd of June when the day is shortest.
We must understand, that when it is Summer Solstice in the Northern Hemisphere, it is Winter Solstice in the Southern Hemisphere and vice versa. This is because of the Earth’s tilt and the Elliptical orbit of the Sun.