What are the interesting natural phenomena in autumn?

In autumn, the most obvious change of natural landscape is in trees. Many fallen leaves will be cleaned up in the city, and many tourists will flock to the mountains to see the red leaves. Let me introduce you to the natural phenomena in autumn. Let's take a look with interested friends!

Natural phenomenon in autumn 1, strange light and shadow show

Besides colorful leaves in autumn, the autumnal equinox also indicates another colorful phenomenon, the Northern Lights. For people who like to watch the sky at night, autumn is still a place besides the benefits of longer and cooler nights. Aurora season? . This is because in autumn, the frequency of geomagnetic storms is twice the annual average.

Particles released by the sun in a magnetic storm will fly to the earth at an alarming speed. When these particles enter the earth's magnetic field, they will collide with atoms and molecules of oxygen, nitrogen and other elements. Therefore, there are dazzling light and shadow performances, the most common ones are pink, green, yellow, blue, purple, and sometimes orange and white, depending on which elements the particles hit.

2. Animal reaction

Creatures will respond to changes in light brought by autumn. Trees begin to shed leaves and animals are ready to hibernate. Autumn will also bring a particularly remarkable phenomenon to male Siberian hamsters at high latitudes, during which their genitals will swell 17 times; To some extent, this expansion enables them to arrange breeding time accurately.

Hamsters are not the only animals that greet autumn in strange ways. Black-crowned tits build nests to collect seeds and hide them in hundreds of different places in trees and fields. At the same time, the hippocampus of this bird will expand by 30%, because new nerve cells are growing in this area of the brain responsible for space management and memory.

3. Full Moon in Autumn

The full moon in autumn has its own specific name, Harvest Moon. From wolf month, sturgeon month, hunting month to harvest month, the full moon will get various names according to the month or season when it rises. The harvested moon looks closest to the autumnal equinox, and this year is from September 18 to September 19.

Before the lights come on, farmers should take advantage of the full moon to harvest their crops quickly. In late summer and early autumn, many crops are ripe at the same time, so farmers have to stay in the fields from morning till night and be busy harvesting. Therefore, moonlight is very important to their harvest, so there is also the saying of Mayday.

4. Why do autumn leaves change color?

Climate change will slow down the color change of autumn leaves. The decrease of temperature and light will change the color of leaves; They will stop producing chlorophyll. With the decrease of green, carotenoids such as orange and yellow began to appear in leaves. Bright red is the effect of anthocyanins produced in autumn.

Scientists warn that the color of autumn leaves may be affected by global warming. Studies have shown that with global warming, the time for leaves to change color will be delayed, because their color switch is turned on by cooling to some extent.

Cool nights and sunny days in autumn also prompt trees such as sugar maple to temporarily store anthocyanins in their leaves, making them appear bright red. But if global warming makes it hotter at night and shorter in autumn, trees may not use sugar to make red pigment, but transport sugar to branches or burn it as a nutrient.

5. When should the autumnal equinox be?

The date of the autumnal equinox changes slightly every year, usually on September 22nd or 23rd. But at 193 1, the autumnal equinox appears on September 24th. The reason is that the Gregorian calendar and the position of the earth in the orbit around the sun are not completely matched.

When the earth revolves around the sun, it rotates around its axis at an inclination of 23.5 degrees, so that it faces the sun in summer solstice, in winter solstice, and at right angles to the sun at the autumnal equinox and vernal equinox. This right angle means that the northern hemisphere received the same amount of sunlight at that time. If it takes 365 days to orbit the sun well, then the date of the autumnal equinox should be the same every year. But in fact, it takes 365.25 days for the earth to go around the sun, so the date changes slightly every year. The autumnal equinox will appear again on September 24, and it will be 2303.

These questions seem simple, but if I ask you why, you must have a hard time answering them. That's how people get used to what has always existed and never observe it carefully. Obviously, our understanding of nature is still insufficient. I hope this common sense can make you pay more attention to nature and the earth where we live.

Beginning of autumn in the autumn solar terms.

Beginning of autumn is the 13 of the 24 solar terms. August 7th or 8th every year, depending on whether the sun reaches the ecliptic 135? This is the beginning of autumn. ? Autumn? It means cool in summer and the beginning of autumn. But in early autumn, the weather in Jianghuai area is still very hot.

According to the standard of dividing seasons according to the average temperature, it must be that the average temperature for five days is below 22℃ to be considered as autumn. According to this standard, the Jianghuai area generally enters autumn in the middle and late September. After beginning of autumn, although it was difficult to get rid of the summer heat for a while, what else was there? Autumn tiger? But the general trend is that the weather is getting colder. The daily temperature range is gradually obvious, which is often very hot during the day and very cold at night.

Autumn actually means that the crops are about to mature. After beginning of autumn, late rice in most parts of South China started jointing and heading, and cotton bolls cracked. Mid-season rice and summer corn entered the stage of grain filling maturity. In the east and west of South China, the task of drought and flood control is still very arduous. South China after beginning of autumn is still in midsummer, but "beginning of autumn is full of yellow in ten days", and a golden "autumn" is coming soon?

The heat is over

Summer is 14 of the 24 solar terms. ? Place? It means go. In summer, the heat stops here, that is, in summer, the hot summer will pass, the temperature will gradually drop, and the rainfall will gradually decrease. But this is just a general rule. In the Jianghuai area, the difference is bigger year by year. In some years, the weather in summer is hotter than that in summer, which is commonly said? Autumn tiger? Weather, because of this, does the Jianghuai area interpret the summer heat as? In hot summer? Yes Therefore, remind people to pay attention to heatstroke prevention at this time. The temperature difference between day and night in the north is gradually increasing, so it is necessary to add clothes in time in the morning and evening to prevent colds.

The conditions of warm day and cool night are very beneficial to the production and accumulation of dry matter of crops. Crops ripen faster, but what about people? In summer, the fields changed overnight? Said. So remind farmers and friends to arrange field farming in time according to weather changes.

Autumn Equinox

The autumnal equinox is a solar term representing seasonal changes. On the day of the autumnal equinox, the sun is located at longitude 180 degrees, and the sunlight is almost direct to the equator, and day and night are almost equal. At this time, the waiting temperature in the southern region has generally dropped below 22℃, and it has entered a cool autumn. "An autumn rain and a cold". The cold air from the south meets the warm and humid air that gradually decays, resulting in repeated rainfall and the temperature dropping again and again. In the northern part of the northwest plateau, the daily minimum temperature has dropped below 0℃, and you can already see the magnificent snow scene flying all over the sky and the earth wrapped in silver.

After the autumnal equinox, rainfall in most parts of the south decreased significantly, and heavy rain and heavy rain rarely appeared. However, rainy days increase, rainy days are frequent, and the night rain rate is high. Li Shangyin, a famous poet in the Tang Dynasty, famously said, "It rains late in autumn pond", which vividly describes the climate characteristics of autumn rainy nights in the south.

It is rainy and humid in autumn in the south and Liangshan Prefecture, which has great influence on autumn harvest, autumn ploughing and autumn planting. It is necessary to grasp the sun, control soil moisture and prevent waterlogging, and do a good job in the quality and progress of Sanqiu production. At the same time, we should make full use of the meteorological conditions of rainy autumn and good soil moisture, seize the opportunity to do a good job in afforestation, and strive to improve the survival rate of saplings.

Cold Dew

Every year1October 8th or 9th 10, depending on whether the sun reaches the longitude of the Yellow River 195? It's cold dew Twenty-four solar terms say: In September, the dew is cold and will condense. ? Cold dew means that the temperature is lower than that of the white dew, and the dew on the ground is colder and will soon condense into frost. In the cold dew season, Nanling and the vast area to the north have entered autumn, and the northeast and northwest regions have entered or are about to enter winter. In the capital Beijing, you can see the first frost in many years. In addition to the perennial snow on the Qinghai-Tibet Plateau, it has generally begun to snow in the northeast and northern Xinjiang.

After the cold dew, the cold air in the north has a certain influence, and most parts of China are controlled by cold high pressure, and the rainy season is over. The weather is often warm during the day and cool at night, with clear skies and Wan Li, which is very beneficial to the autumn harvest. Thunderstorms have disappeared in most parts of Chinese mainland, and only Yunnan, Sichuan and Guizhou can hear thunder. The precipitation in June 5438+ 10 in North China is generally only half or less than that in September, while in Northwest China it is only a few millimeters to more than 20 millimeters. Drought and lack of rain often bring difficulties to timely sowing of winter wheat and become one of the main limiting factors for high yield of dry land wheat.

At this time, it is still autumn rain in Hainan and Southwest China, and rainy weather will also occur in Jianghuai and Jiangnan in a few years, which will have a certain impact on autumn harvest and autumn planting.

? Cold dew does not pick cotton, why complain about frost. . When the weather is good, we should pay close attention to harvesting cotton. When the temperature drops early, we can take it back when the temperature is not too low. One-season late rice is about to mature in Jianghuai and Jiangnan, and double-season late rice is filling. Pay attention to intermittent irrigation to keep the fields moist. Should we pay attention to defense in southern rice areas? Cold dew wind? Hurt. North China should hurry to sow wheat. At this time, in case of drought and little rain, we should try our best to accumulate soil moisture, grab soil moisture for sowing, and ensure that sowing is completed before and after the first frost. We must not passively wait for rain to lead to planting early crops and late wheat. Before and after the cold dew is the suitable sowing date for direct seeding rape in the Yangtze River basin, and the variety arrangement should be that Gan Lan-type varieties should be sown first, and then cabbage-type varieties should be sown. Those who sow green manure in the south of Huaihe River should be cleaned up, and those who have emerged should be cleaned and drained to prevent waterlogging. The tuber expansion of sweet potato in North China Plain gradually stopped. At this time, the probability that the morning temperature is lower than 10℃ or lower is gradually increasing. We should pay close attention to harvesting according to the weather conditions and strive to finish it before the first frost, otherwise, potato tubers will be frozen due to long-term exposure to the low temperature underground. Hard-hearted , reduce the value of food, feed and industry, can not be stored or used as seeds.

Frost's Descent

The solar term of the first frost is1October 23rd or 24th every year, 10. According to the 24 solar terms: In mid-September, the gas was cold and condensed, and the dew was like frost. ? It can be seen that the first frost refers to the beginning of frost. However, China has a vast territory and the climate varies greatly from place to place. First frost. First frost? It reflects the climate characteristics of the Yellow River basin. As far as the annual frost days are concerned, there are frost and snow in some parts of the Qinghai-Tibet Plateau even in summer, and the annual frost days are over 200, which is the place with the largest number of frost days in China. The annual frost days in eastern Tibet, southern Qinghai, Qilian Mountains, western Sichuan Plateau, northwestern Yunnan, Tianshan Mountains, Altai Mountains, western mountainous areas of northern Xinjiang, northeast China and eastern Inner Mongolia all exceed 100 days, and the vast areas south of Huaihe River and Hanshui River and east of Dongpo of Qinghai-Tibet Plateau are all below 50 days, with latitude of 25? There is only about 10 day in the south and Sichuan Basin, and the average annual frost days in the south of Fuzhou and the coastal areas of Guangdong and Guangxi are less than days, while Xishuangbanna, Hainan, the south of Taiwan Province Province and the South China Sea Islands are places without first frost.

The appearance of frost shows that the lowest ground temperature has reached below 0℃, which will have a certain impact on crops. The first frost in autumn is called the first frost. The earlier the first frost, the greater the harm to crops. The first frost in all parts of China is gradually delayed from north to south and from mountainous areas to plains. Except for areas with frost all the year round, frost first appeared in the north of Daxing 'anling, usually at the end of August. The first frost in most parts of Northeast China, Inner Mongolia and Northern Xinjiang is mostly in September. 10 Frost has appeared in Shenyang, Chengde, Yulin, Qamdo and Lhasa. 165438+1Frost has been seen in Shandong Peninsula, Zhengzhou, Xi 'an and northwest Yunnan in early October; 30 north latitude in eastern China? About, Yunnan Hanshui, latitude 2? Frost will not be seen in the surrounding areas until the beginning of 65438+February; First frost from Xiamen and Guangzhou to Baise and Simao is 65438+1early October after the New Year.

In the first frost season, the cool autumn wind blew to Guangzhou, the flower city. The average temperature in the northeast, eastern Inner Mongolia and most of the northwest has been below 0℃, the soil has frozen, and the winter crops have stopped growing and entered the wintering period. For soybean harvest in North China, spring varieties should be selected for late wheat that has not been sown, and seedlings should be checked and replanted for those that have emerged. The Yangtze river basin is in the golden season of winter wheat sowing. Rape has generally entered the two-leaf stage, so it is necessary to sow in time, weed in intertillage and control aphids. Late-maturing rape that has not been planted due to floods in disaster areas can be sown with wet ash manure first, and then sown indoors to accelerate the emergence of seedlings. ? If you don't cut the first frost, you lose a reed a day? Harvest the late rice when it is ripe to prevent bird damage and grain dropping. The Chinese cabbage in North China is about to be harvested, so the later management should be strengthened.

In the first frost season, most parts of China enter the dry season, so we should attach great importance to forest protection and fire prevention.

The beauty of autumn is mature-it is not as shy as spring, so open in summer and so introverted in winter.

2. Autumn, harvest season, golden season-as lovely as spring, as enthusiastic as summer, as charming as winter.

3. The sunshine in autumn is warm and quiet, the autumn wind in Dong township is warm and gentle, and the blue sky and white clouds are elegant and melodious.

The golden rice fields in the distance roll like golden waves under the autumn wind, which is very spectacular.

As soon as September comes, autumn comes. It slips away in the foggy dawn and disappears in the hot afternoon. It tiptoed past the top of the tree, dyed a few leaves red, and then left the valley like a gust of wind.

6. In another night or two, the autumn frost will cover the valley under the moon, and then retreat to the northern mountains for a short stay, so that the golden early autumn can gently soothe the earth. There is a faint smell of fennel in the sky. And the fragrance of Jin Ju. The fog billowed and was broken by the moonlight in September, revealing a blue sky.

7. Autumn, always the blue sky, will suddenly turn its face and reveal sinister colors. Tropical typhoon accompanied by Miyun rainstorm, flood undercurrent surging, the struggle of the recovered grassland finally gradually revealed. The fields exude a leisurely atmosphere from its broad chest, and the slopes and dams spread out like water. The surrounding trees and crops are swaying in the breeze, and the leaves become calm and wide. Dew came back, wet the ridge in the morning and evening, and hung quietly in the field. Lululan also came to the dam, floating quietly and never returning to the valley. Although the sunshine is still bright, it is no longer painful, but it becomes broad-minded and clear, as if it is finally powerless, and it is impossible to steam the field and reconcile with it; Autumn is coming!

The sight of jumping into the window made me feel deja vu. Blue sky and white clouds, wild mountains, weeds washed yellow by autumn frost, just like a virgin in a golden gauze, naked and ivory, dancing in the bleak autumn wind, showing a charming appearance. Standing on the top of the mountain, Qiuyang, like a mighty god of war, shook off his bloody shirt, splashed on the grass, infiltrated into the stream below the mountain, sobbed and flowed outward with countless ripples, from ancient times to the present, from the distant past to the infinite future.

9. People often say that autumn is golden, right? Indeed, she has brought abundant fruits to nature and provided countless foods to many creatures, including people, to prolong their lives.

10. Only in autumn do you know that the season of life has quietly disappeared. Under the leaves and rustling wind, it is difficult to remember how the new green of hope germinated in spring.

1 1. You left. During that long time, my heart, like Qiu Shu, always floated helplessly, only loneliness hung in my heart.

12. Autumn wind and red leaves are floating all over the sky, but you know that spring is still far away! Since the north wind broke the ice, I am disheartened and unhappy. Pangu's creation is just a new life. Ask a woman when the moon shines. The spring breeze laughed, hoping to get drunk today!

13. Autumn wind and autumn rain are cool, autumn branches, autumn leaves and autumn grass are yellow, autumn clouds and autumn moon are cool, autumn chrysanthemum and autumn geese are busy with autumn harvest, autumn sentiment is lingering, Qiu Si is sad in autumn, and the weather is cool. Remember to add autumn clothes, don't catch cold! Deep courtyard lock clear autumn!

14. The whole golden world is immersed in the embellishment of autumn rain. Autumn is like a fairy, and the earth becomes very bright with the light dance steps. Maple leaves float to the golden land like burning flames. People carry backpacks and play in the wild in the autumn wind.

15. In this golden autumn season, autumn beauty is mature and lovely. Although it is not as refreshing as spring, it has the warmth of spring. Although there is no heat in summer, there is passion in summer; Although it is not cold in winter, it has unique beauty.

16. You see, the top of that mountain is misty and rainy, like white dragons winding around the green hills. In the white smoke, you can occasionally see golden rice, yellow and white constitute a seemingly light but beautiful picture.