When the Equinox phenomenon occurs, the sun shines directly on the equator, and the length of day and night is nearly the same worldwide. Then on March 20, there is the March Equinox phenomenon where the sun will shine directly on the equator, and the length of day and night is almost equal worldwide.
This Equinox phenomenon occurs twice a year, in March (Vernal Equinox) and in September (Autumnal Equinox). According to BRIN, the Equinox for September is predicted to occur on September 22, 2024.
What is the Equinox Phenomenon?
Equinox is a phenomenon that occurs when the position of the Sun is directly above the equator. Periodically, the Equinox occurs twice a year, in March and September.
During the Equinox phenomenon, sunlight is distributed almost equally outside the Earth's region, including areas in the northern and southern subtropics. Additionally, during the Equinox phenomenon, the Sun and Earth are closest together.
This causes the tropical regions around the equator to receive maximum sunlight, leading to a drastic increase in air temperature. However, this phenomenon does not always result in extreme or drastic increases in air temperature.
Is Equinox Dangerous?
Equinox is a natural astronomical phenomenon. Equinox is not like HeatWave phenomena that can cause significant and prolonged increases in air temperature.
Therefore, people do not need to worry about the effects of Equinox, as it is not dangerous. Thus, there is no need for panic or concern about drastic temperature increases due to Equinox, as it does not impact health.
Time and Date Season Equinox
The March Equinox falls on March 20, 2024. This event is marked by the Sun's position directly above the equator, resulting in the phenomenon of a shadowless day. This moment also signifies the arrival of spring in the northern hemisphere and the beginning of autumn in the southern hemisphere.
Every year, the March Equinox occurs between March 19-21. This annual astronomical phenomenon holds significant meaning in human life. Besides heralding seasonal changes that alter habits and lifestyles, many cultures use the March Equinox as a reference point for various celebrations symbolizing happiness.
During the Equinox, residents near the Earth's equator can experience a "shadowless day." At noon, when the Sun is directly overhead, object shadows appear perpendicular, giving the impression of no shadows.
Although the March Equinox falls on a Wednesday, this phenomenon can be experienced for approximately two days around the equinox date.
However, this event is exclusive to those living near the equator.
During the equinox, all locations on Earth experience equal lengths of day and night, approximately 12 hours each. This equality in Latin is called "equinox," meaning 'equal night.'
However, the actual length of daylight and nighttime during the March Equinox is not precisely 12 hours but slightly varies depending on the distance from the equator. Currently, many places on Earth have slightly longer daylight hours than nighttime hours. This condition is influenced by sunlight reflection by the Earth's atmosphere and the definitions of sunrise and sunset used.
During the March Equinox on Wednesday (20/3/2024), daytime in New York, USA, lasts 12 hours and 10 minutes; Mecca, Saudi Arabia, 12 hours and 7 minutes; and Longyearbyen, Norway, located in the Arctic Circle, has daytime lasting 12 hours and 37 minutes. Meanwhile, Melbourne, Australia, in the southern hemisphere, enjoys 12 hours and 8 minutes of daylight.
Meanwhile, those living at the equator will experience longer daytime than nighttime throughout the year. This is the advantage of living near the equator, as it avoids extreme changes in day and night like in countries with four seasons.
Seasonal Changes
The March Equinox, as quoted from LiveScience, marks the end of the freezing winter and the arrival of warm spring in the northern hemisphere. Therefore, the March Equinox is referred to as the vernal/spring equinox.
Meanwhile, for those in the southern hemisphere, the March Equinox signifies the end of a joyful summer and the arrival of autumn, also known as the fall equinox.
After today, the Sun will move northward towards the northern hemisphere until it reaches its farthest point, known as the summer solstice, in June. This journey results in longer daylight hours than nighttime hours in the northern hemisphere.
Conversely, the southern hemisphere experiences the opposite. As the Sun moves northward, the southern hemisphere receives less sunlight. Consequently, nighttime becomes longer, reaching its peak during June, while their counterparts in the northern hemisphere experience summer.
This phenomenon repeats every year, creating regular and consistent seasonal variations. The back and forth apparent motion of the Sun is due to the Earth's tilted axis of rotation by 23.4 degrees relative to the ecliptic plane or the Earth's orbit around the Sun.
While rotating on its axis, the Earth also orbits around the Sun. As a result, the part of the Earth inclined toward the Sun alternates. When the northern hemisphere tilts towards the Sun, it receives more sunlight, while the southern hemisphere receives less. The reverse is also true.
Meanwhile, during the equinoxes, the Earth's axis of rotation is perpendicular to the ecliptic plane, and the direction of sunlight. Consequently, the entire Earth receives the Sun's light evenly, resulting in almost equal lengths of daytime and nighttime.
In a year, equinoxes occur twice: the March Equinox when the Sun's apparent motion is from the southern hemisphere to the northern hemisphere, and the September Equinox when the Sun's apparent motion is reversed, from the northern hemisphere to the southern hemisphere. The March Equinox occurs between March 19-21, while the September Equinox occurs between September 22-24 each year.
Not only determining seasonal changes, but the March Equinox is also used as a reference point for measuring the length of a tropical year, the average time it takes for the Earth to complete one orbit around the Sun. From March 2023 to March 2024, the length of one tropical year is 365 days, 5 hours, 42 minutes, and 8 seconds. This is the shortest tropical year in the last five years. The longest occurred from March 2021 to March 2022, which was 365 days, 5 hours, 55 minutes, and 54 seconds, a difference of only 13-14 minutes.
For Indonesians, the March Equinox can also mark a seasonal change. The March Equinox signals the transition from the rainy season to the dry season.
The varying length of the tropical year explains why the equinox days vary each year, although within a certain range. The length of one year in the Gregorian calendar used is not exactly the same as the length of one tropical year required for the Earth to complete one full orbit around the Sun.
As the southern hemisphere gets colder, air pressure increases. Conversely, in the warming northern hemisphere, air pressure decreases. As a result, monsoon winds blow from the Australian continent towards Asia.
Passing over continental landmasses, these eastern monsoon winds are dry and bring the dry season, affecting 88 percent of Indonesia's population south of the equator. However, climate change has slightly altered the predictability of this climate pattern.
Celebrations
For people living in subtropical regions or high latitudes, the March Equinox holds significance, especially for 88-90 percent of people living in the northern hemisphere. The end of winter and the arrival of spring mean the end of biting cold and the beginning of warmer air.
This condition allows people to spend more time outdoors. They can enjoy the greenery, blooming flowers, or the chirping of birds in the morning. Grasses regrow, allowing livestock to graze in pastures and feed on fresh grass. Agricultural activities can resume after a temporary pause during winter.
Because of this, the March Equinox is celebrated in the northern hemisphere. The March Equinox marks a new beginning, new hope, and new happiness.
The March Equinox serves as a reference point for determining the date of Easter. Claus Tøndering, in Frequently Asked Questions about Calendars (2005), mentions that the Council of Nicaea in 325 AD established Easter to be celebrated on the first Sunday after the first full moon following the March Equinox.
If the full moon falls on a Sunday, then Easter is celebrated the following Sunday. This rule ensures that the commemoration of Jesus' resurrection occurs on the same day and season as the event itself, around the year 30.
If this March Equinox occurs on a Wednesday, then the next full moon, as quoted from Time and Date, will occur on the following Monday (25/3/2024), peaking at 2:00 PM Western Indonesian Time (WIB). Therefore, Easter Sunday falls on Sunday (31/3/2024).
In many Christian cultures, Easter is associated with Easter eggs, chicken eggs decorated as symbols of fertility and rebirth. This celebration often involves using eggs as the main medium, starting from decorating eggs, searching for colorful Easter eggs, to egg dances.
This tradition has also given rise to the myth that people can only balance eggs perfectly during the March Equinox. However, in reality, achieving a perfect balance with eggs can be done on any day throughout the year.
The Iranian New Year, Nowruz, also falls during the March Equinox, on Wednesday (20/3/2024). This New Year celebration rooted in the Persian calendar has been observed for more than 3,000 years and emerged from Zoroastrianism traditions. Before the 12-day celebration begins, some Iranians buy new clothes and clean their homes.
Meanwhile, in Japan, the March Equinox marks the arrival of Higan, a week-long Buddhist observance to honor ancestors who have attained nirvana. This celebration also commemorates the spiritual transition of their ancestors' spirits from the world of suffering to enlightenment. Both the March and September Equinoxes have been designated as national holidays since the Meiji era (1868-1912).
Additionally, March 20 is also celebrated as Earth Equinox Day. Unlike Earth Day on April 22, which is celebrated to raise awareness of the importance of preserving the Earth, Earth Equinox Day is celebrated to emphasize the unity of all humans on Earth. Regardless of nationality, religion, or culture, we all live on the same Earth.
