Winter Solstice and its Significance
The term “solstice” has been derived from the Latin words sol (Sun) and sister (to stand still). During the solstice, the angle between the plane of the Earth’s equator called declination and the Sun’s rays seems to stand still. Winter solstice occurs for the duration of two months during the year when the path of the Sun is farthest north in the Southern Hemisphere (June 20/21) and farthest south in the Northern Hemisphere (December 21/22). It is also known as the Hibernal Solstice or the Hiemal Solstice. The term midwinter has been used for winter solstice since the 18th century. At the time of winter solstice, the path of the Sun in the sky is the shortest. This is the reason why there is the least daylight and the longest night on this date.
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Winter Solstice Great Conjunction
In 2020 the longest night of the year on December 21 witnessed an extraordinary astronomic event which is known as the Winter Solstice Great Conjunction. Jupiter and Saturn, the two largest planets of the solar system almost overlapped each other to form a double planet. This event could be witnessed from anywhere in the world and was a phenomenon that has occurred almost after 800 years. Winter Solstice Great Conjunction was also called Christmas Star of the Year.
Winter Solstice in the Hemispheres
Now that you know what is winter solstice let’s see what happens during this period in the hemispheres. In the Northern Hemisphere, the North Pole is tilted about 23.4° (23°27′) away from the Sun at the time of winter solstice date. As the rays shift southward from the Equator by the same degree, the vertical noon rays fall directly overhead at the Tropic of Capricorn (23°27′ S). After six months, the South Pole gets inclined about 23.4° away from the Sun. On this winter solstice Southern Hemisphere date, the sun’s rays are vertically overhead to their northernmost position, the Tropic of Cancer (23°27′ N).
Winter solstice marks the onset of the winter season according to the astronomical definition of the seasons. This season lasts until the start of the vernal equinox which starts on March 20/21 in the Northern Hemisphere and on September 22/23 in the Southern Hemisphere. After the solstice date, the days start to get longer. This day is also celebrated in many cultures as a time of rebirth.
In several temperate regions, the winter solstice is considered the middle of winter, but in most calendars and countries it marks the beginning of the winter season.
Difference Between the Summer Solstice and the Winter Solstice
Conclusion
You know what is winter solstice is and when it occurs but it also has historical and cultural significance. Winter solstice holds significant importance in several cultures and is often marked by rituals and festivals. It is also considered as the time of the symbolic death and rebirth of the Sun.
FAQs on Winter Solstice
1. What is the winter solstice as per Geography concepts?
The winter solstice, also known as the hibernal solstice, is an astronomical event that marks the shortest day and the longest night of the year. It occurs when one of the Earth's poles has its maximum tilt away from the Sun. This happens twice annually, once in the Northern Hemisphere (around December 21) and once in the Southern Hemisphere (around June 21).
2. What happens to the Sun's position and daylight hours during a winter solstice?
During the winter solstice, the Sun is at its lowest daily maximum elevation in the sky. For the hemisphere experiencing winter, this results in the shortest period of daylight and consequently, the longest night of the year. For instance, in the Northern Hemisphere around December 21, the Sun's direct rays are over the Tropic of Capricorn in the Southern Hemisphere.
3. How is a solstice different from an equinox?
The primary difference lies in the Earth's axial tilt relative to the Sun.
- A solstice occurs at the point of maximum tilt, causing the longest or shortest day (Summer and Winter Solstice).
- An equinox occurs when the Earth's tilt is neutral (neither towards nor away from the Sun), resulting in nearly equal hours of daylight and night. The two equinoxes are the vernal (spring) equinox around March 21 and the autumnal equinox around September 23.
4. Why does the winter solstice occur in December for the Northern Hemisphere but in June for the Southern Hemisphere?
This happens because of the Earth's consistent axial tilt of about 23.5 degrees. As the Earth orbits the Sun, the seasons are opposite in the two hemispheres. In December, the Northern Hemisphere is tilted away from the Sun, causing its winter solstice. Simultaneously, the Southern Hemisphere is tilted towards the Sun, so it experiences its summer solstice. The reverse is true in June.
5. Does the winter solstice always fall on the same date every year?
No, the date can vary slightly. In the Northern Hemisphere, it most often occurs on December 21 or 22. This variation is because the Gregorian calendar has 365 days, while the Earth's orbit around the Sun (the tropical year) takes approximately 365.24 days. The inclusion of a leap year every four years helps to recalibrate the calendar and prevent the date of the solstice from drifting.
6. How is the concept of the winter solstice explained for Class 6 students as per the NCERT syllabus?
According to the CBSE/NCERT curriculum for Class 6, the winter solstice is explained as a key position in the Earth's revolution. It is the time of year when the Sun's rays shine directly on the Tropic of Capricorn. Consequently, the Northern Hemisphere, being tilted away from the sun, receives less direct sunlight, leading to longer nights, shorter days, and the winter season.
7. What is the cultural importance or real-world example of the winter solstice?
Beyond its astronomical definition, the winter solstice holds significant cultural importance. Many ancient cultures celebrated it as a moment of rebirth and the symbolic return of the sun. Examples of such celebrations include:
- The ancient Roman festival of Saturnalia.
- The pagan celebration of Yule in Germanic traditions.
- The Dongzhi Festival in China and other East Asian cultures, which celebrates the return of longer daylight hours.
