O autumn it is the season that begins after summer and precedes winter. Because of this, she is considered a transition station. In the Southern Hemisphere and, therefore, in Brazil, autumn starts between March 20th and 21st, while in the Northern Hemisphere it starts between September 22nd and 23rd. Some of the main features of this station are the gradual reduction of temperatures, as well as the reduction of daily light time. Autumn is also known as the fruit season.
See too: What is the difference between weather and weather?
Mind Map: Seasons of the Year
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When does autumn start?
THE occurrence of the phenomenon of equinox autumn marks the arrival of that season. The equinox represents the moment when the sun's rays fall perpendicularly on the Lfrom the ANDquadra, and the luminosity is distributed relatively evenly between the Northern and Southern hemispheres.
However, it must be remembered that the beginning of autumn does not happen simultaneously in both hemispheres:
- North hemisphere: starts between the 22nd and 23rd of September;
- South hemisphere: starts in March, between the 20th and 21st.
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Autumn Characteristics
Autumn is the season of the year that follows the summer and precedes the arrival of the Winter. Therefore, it can be considered a transition period between these two seasons. One of the main features of autumn is the gradual reduction of daily temperatures, which go from elevated to milder, anticipating the cold period that follows.
In addition to temperature changes, the season is marked by higher incidence of winds and reduced air humidity. There may be the formation of fog in the morning, in addition to the occurrence of frost and, in some cases, even precipitation in the form of snow.
Initially, the days and nights have the same duration, that is, 12 hours. As autumn progresses and winter approaches, the days get shorter and the nights get longer.
The transformation of the vegetation cover is the most striking aspect of autumn. The foliage of the trees acquires a color that varies between yellowish and reddish tones, as a result of the lower incidence of sunlight and reduced production of chlorophyll. In the case of deciduous species (still known as deciduous), leaves fall, a plant protection mechanism.
The Earth's temperate zones, which are two of the thermal zones in which the planet divides, are located in mid-latitudes and are those in which the characteristics of autumn are more accentuated and the season is better demarcated.
See too: Influence of ocean currents on climate
Autumn in the Northern Hemisphere
The beginning of autumn in the Northern Hemisphere takes place between the 22nd and 23rd of September, and it ends between the 21st and 22nd of December. In this same period of time, the Southern Hemisphere is going through the spring. The station can also be called northern autumn, in reference to the north.
The transition between seasonsof the year and the main features of each are most noticeable in the temperate zones of the globe, as discussed earlier. In the Northern Hemisphere, this area is located between the Arctic Circle (66º33’N) and the Tropic of Cancer (23º27’N).
The change in temperature and the modification in the landscape through the color of tree leaves are the most striking aspects of autumn in the Northern Hemisphere. Also, there is a increased cloudiness and precipitation indices near the end of the season. In many countries, the first snow is still in autumn.
There may also be the occurrence of a climatic phenomenon called summery (or indian summer, in English), which consists of an abnormal increase in average temperatures for that season. The summer also happens in winter.
Autumn in the Southern Hemisphere
The beginning of autumn in the Southern Hemisphere takes place between the 20th and 21st of March, and it ends between the 20th and 21st of June. Meanwhile, the Northern Hemisphere is experiencing its spring. The station can be called austral autumn, in reference to the south.
Following the same pattern described for the areas located above the Equator, it is in the intermediate latitudes that the autumnal characteristics are most noticeable. These areas lie between the Tropic of Capricorn (23º27’S) and the Antarctic Polar Circle (66º33’S).
THE progressive drop in temperature in the autumn months and the reduction of air humidity and rainfall are the main aspects of the season in the Southern Hemisphere. There is also the occurrence of the Indian summer, which lasts for a few days.
Autumn in Brazil
The Brazilian autumn starts in March and has an average duration of three months. Most of Brazil is located in the tropical zone of the planet and, as a result, the characteristics of this season of the year become more diffuse. In a portion of the RSoutheast region and on Rsouthern region, autumn is more prominent than in other regions.
According to Inpe's Center for Weather Forecasting and Climate Studies (CPTEC), autumn in Brazil has characteristics that are typical of the transition between summer and winter, with significant changes in conditions temporal. That includes:
- temperature;
- air humidity;
- incidence of winds; and
- volume of rains.
the regions North and North East of the country record high temperatures for the period, which range between 22º C and 32º C, and also the highest rainfall in autumn for the country. Rains are more voluminous in areas closer to the Equator.
Temperatures in the regions Midwest, Southeast and South of Brazil show a decrease, which is due to the influence of cold air masses that enter the Brazilian territory. The minima can be up to 10º C in mountainous regions, and the maximum oscillate between 18º and 28º C, according to CPTEC information. Rainfall rates are lower in these regions, and, especially in the higher areas of the South and Southeast, the formation of fog and the occurrence of frost is common.
fruit season
In both hemispheres, the arrival of autumn marks the beginning of the harvest period. Due to the wide variety of fruits that are in the final phase of their productive cycle, autumn is known as the fruit season.
Some fruits of this season are:
- Apple;
- papaya;
- Orange;
- pear;
- grape;
- avocado;
- coconut;
- star fruit;
- banana;
- Kiwi;
- guava;
- fig;
- mango;
- khaki.
The importance of its consumption lies in the high nutritional index of these foods, which are rich in vitamins, minerals and fibers, which bring several health benefits and can help prevent disease.
*Mental Map by Rafaela Sousa, graduated in Geography
By Paloma Guitarrara
Geography teacher
