Arab weather - astronomical calculations indicate that the date of the spring equinox in the northern hemisphere for this year falls on Sunday, March 20, at 06:32 pm Mecca time, when the sun is perpendicular to the equator, and thus the season passes. Winter marks the beginning of spring.
(An illustrative drawing of the sun’s rays perpendicular to the equator, which means that the earth on this day is not tilted from the horizon (note: the size of the sun and the earth is illustrative and does not take into account the true ratio between them))
What happens astronomically on the day of the vernal equinox?
The Earth revolves around the Sun while its axis tilts about 23.5 degrees from the horizon. The Northern Hemisphere tilts toward the Sun during the summer months, and it tilts away from the Sun during the winter months, and the opposite occurs in the Southern Hemisphere.
But it happens twice a year that the Earth’s axis is perpendicular to the plane of its rotation around the sun, so that there is no tilt of the Earth with respect to the sun, and then the equinox occurs twice during the year, the day of the spring equinox in March, and the day of the autumnal equinox in September.
Because of the Earth's equinox and non-inclination in front of the sun's rays, the world gets about 12 hours of day and about 12 hours of night, meaning that night and day are equal all over the world.
(On the equinox day, the earth is not tilted in relation to the sun, so the sun’s rays are perpendicular to the equator, the hours of night and day are equal, and the line separating day and night passes through the poles of the earth)
In the following, we will learn about facts about the day of the vernal equinox that make it a special day from the rest of the year:
- The spring season begins astronomically and officially on the day of the vernal equinox in one hemisphere, while the autumn season begins astronomically and officially in the other hemisphere.
- Spring lasts about 92 days, from the vernal equinox to the summer solstice.
- On the equinox, the sun is perpendicular in its apparent journey across the horizon at the Earth's equator.
- Day and night are equal around the world on the equinox.
- On the globe, the dividing line between day and night passes through the Earth's north and south poles.
- The equinox is an opportunity to determine exact directions because the sun rises in the true east (at a 90-degree angle to the horizon) and sets in the true west (at a 270-degree angle with the horizon).
- On the vernal equinox in March, the sun sets for the first time in the Antarctic after a 6-month day.
- On the vernal equinox in March, the sun rises for the first time in the North Pole after a night of 6 months.
- The vernal equinox does not necessarily mean that the warmth begins immediately or there are rapid changes in the weather.
- With the onset of spring, the chances of rain decrease and the presence of clouds decreases, which means that a greater amount of sunlight reaches the surface of the earth and plants, which stimulates the growth of plants and tree leaves.
Read also: Facts about the spring equinox in Jordan for the year 2022... and the changing features of the weather
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