Autumn, with its warm color palette and falling golden leaves, is one of the most appreciated seasons by many people around the world. It is a period of transition that marks the farewell of the heat of summer and the announcement of the cold months of winter . But when exactly does autumn begin and what are the scientific reasons behind this fascinating season? In this article, we will explore both the start date of autumn and the natural phenomena that accompany it.
The Start Date of Autumn
The start date of autumn will vary depending on the region and culture, but in astronomical terms, autumn begins with the autumn equinox. The equinoxes are astronomical events that occur twice a year when the Sun is exactly above the Earth's equator. During the autumn equinox, the Sun crosses the celestial equator from north to south. This occurs around September 22 or 23 in the northern hemisphere and March 20 or 21 in the southern hemisphere.
The term "equinox" comes from Latin "aequinoctium", which means "equal night". This is because, during the equinoxes, the length of day and night is approximately the same everywhere in the world. After the autumn equinox in the northern hemisphere, the days begin to get shorter and the nights get longer, marking the beginning of autumn.
Start Autumn 2023 in Spain
For this year, the beginning of autumn in the northern hemisphere, and more specifically in Spain, is marked on the calendar for Saturday, September 23 at 8:50 hours, according to information from the National Astronomical Observatory of Spain.
The < strong>durationof this season will be about 89 days and 21 hours. In this way, it will be concluded on Friday, December 22, 2023, with the beginning of the winter season, long awaited by people who love the cold. p>
Astronomical and Geographical Factors
Astronomical and geographical factors are crucial to determine when fall begins in a specific region. Here are some reasons behind the start date of autumn:
- Tilt of the Earth's Axis: The Earth has a tilted axis of rotation in relation to its orbit around the Sun. This inclination of the axis is what gives rise to the seasons. When a region of the Earth is tilted towards the Sun, it experiences summer, while when it is tilted away from the Sun, it experiences winter. The equinoxes, including the autumnal equinox, occur when the Earth is in an intermediate position in its orbit, so that neither the north pole nor the south pole are tilted toward the Sun.
- Elliptical Orbit of the Earth:Although the autumnal equinox marks the beginning of astronomical autumn, the Earth follows an elliptical orbit around the Sun. This means that the speed of the Earth in its orbit is not constant. Consequently, the duration of the seasons is not completely uniform. Astronomical autumn can have a slightly different length each year, but generally runs from late September to late December in the northern hemisphere.
- Geographical Factors: Geographical location as well influences when autumn begins. In regions close to the equator, such as some countries in Central America and Africa, the seasons are not as marked as in regions further from the equator. In these areas, temperatures tend to remain relatively constant throughout the year, with minimal variations in the length of days and nights.
Astronomical Phenomena Fall 2023
Each year and season has its astronomical peculiarities, and this 2023 was not going to be left behind. And throughout this autumn season 2023 we will be able to enjoy two eclipses, one solar and one lunar. The solar will take place on October 14 and can be seen mainly from America. The lunar, for its part, will happen 14 days later, on October 28. This one, predictably, can be seen from America, Europe, Africa, Asia and Australia.
We will also be able to observe meteor showers during the fall of 2023. of the draconids, as well as the full moons on September 29, October 28 and November 27.
Natural Phenomena of Autumn
Autumn is a season that is characterized by a series of phenomena fascinating natural Some of the most notable include:
- Leaf Color Change: One of the most emblematic aspects of autumn is the transformation of the colors of the leaves of the trees. trees. This phenomenon is due to a combination of factors, including decreased sunlight and reduced chlorophyll production in the leaves. Carotenoid pigments, which produce yellow and orange colors, and anthocyanins, which produce red and purple colors, become more visible as chlorophyll breaks down.
- Leaf Fall: As autumn progresses, the leaves of the trees begin to fall. This process, known as leaf abscission, is an adaptation of plants to conserve energy and water during the colder, drier months of winter. Fallen leaves also contribute to the formation of mulch, which protects the soil and provides nutrients as they decompose.
- Bird Migration: Autumn is a time of migration for Many birds. As temperatures drop and days get shorter, birds that nest in colder regions take flight to warmer climates in search of food and shelter. This migratory spectacle is astonishing and often becomes a highlight for bird watchers.
- Crop Harvest: In many agricultural regions, autumn is a harvest time. Farmers pick ripe crops, such as corn, apples, grapes and pumpkins. The harvest is not only important for human nutrition, but also plays a crucial role in the economy of many rural areas.