Why doesn't it snow heavily in Sichuan Basin?
The geographical location of Sichuan leads to less snow.
Sichuan belongs to the subtropical climate zone, and because it is close to the equator, the cold air in the north can't reach Sichuan. Secondly, there are many mountains around Sichuan, which leads to a lot of weakening even if the cold air comes. The temperature in winter in Sichuan is generally 6 to 1 1 degree.
But it will snow in Sichuan, too
Northwest Sichuan and southwest Sichuan belong to plateau areas, and even some mountains in this area have snow all the year round. Xiling Snow Mountain is very famous. For the plain areas in the basin, it never snows, but it snows every few years, but the amount of snow is small.
20 18 There was a heavy snow in Hailuogou, and this place became a kingdom of ice and snow overnight.
Accurately speaking, there has been heavy snow in Sichuan basin, but it is not an order of magnitude compared with the north. The reason why there is no heavy snow is latitude. The north-south latitude of the Sichuan Basin is between 28 and 32 degrees north latitude, which covers Hubei, northern Hunan, southern Anhui, northwestern Jiangxi and the Yangtze River Delta, basically on the north and south sides of the middle and lower reaches of the Yangtze River. The probability of heavy snow in these areas is very low. This problem should be discussed more. Why is the snowfall in Sichuan Basin less frequent than that in other areas of the same latitude? We can often see from the discussion of central heating in the south and freezing rain in Hunan that the snowfall in winter in Hunan and Hubei is more and more frequent. Although there is no blizzard and heavy snow in the north, medium snow and light snow are also prone to disasters in these areas. In contrast, there is less snowfall in Sichuan Basin. Sichuan Basin is surrounded by mountain plateaus such as Daba Mountain, Qinghai-Tibet Plateau, Yunnan-Guizhou Plateau and Wushan Mountain. The average elevation in the basin is only 400-500 meters, while the average elevation in the surrounding mountains and plateaus is above 2500 meters. The Qinghai-Tibet Plateau in the west is 4000-5000 meters, and the Yunnan-Guizhou Plateau in the south is 2000-4000 meters. Under heavy encirclement, it is difficult for cold air to invade the basin. Many friends who have traveled to Sichuan will basically find a phenomenon. Cities in the basin are also foggy in winter, with few sunny days. This is because the inland potential in the basin is low and cold air can't enter, but the water vapor in the basin is not easy to spread. It is like a "greenhouse" hanging over the basin, which not only has a certain thermal insulation effect, but also is not easy to interact with the upper cold air to cause snowfall. Of course, the Sichuan basin is more than 400 kilometers north and south, and the snowfall in northern Sichuan is still higher than that in southern Sichuan. Welcome to pay attention to the "geographically interesting" message and discuss it together.
This is a classic topic, and there are many questions, such as why the isotherm bends to a high latitude when it passes through Sichuan Basin in June+10 in 5438, why the temperature in Sichuan Basin is higher in winter or why the temperature in Sichuan Basin is higher than that in the middle and lower reaches of the Yangtze River, and so on. Are exactly the same as the question "Why doesn't it snow heavily in Sichuan Basin?". To understand this problem, we must first understand the geographical environment of Sichuan basin.
Sichuan Basin is one of the four great basin in China's traditional understanding, and occupies the third place in China (Tarim Basin, Junggar Basin and Qaidam Basin). Generally speaking, the southeast and northwest of Sichuan Basin are surrounded by Wushan, Dalou Mountain, Yunnan-Guizhou Plateau, Qinghai-Tibet Plateau and Qinba Mountain, with a total area of about 260,000 square kilometers, including most cities in central and eastern Sichuan Province (Chengdu
According to the topographical features of Sichuan Basin, the edge of the basin is completely surrounded by mountains or plateaus with an altitude of1000-3000m, while the elevation of the bottom of the basin is generally 250-750m. Because this kind of terrain is relatively closed, it has a mechanical blocking effect on airflow. The Qinba Mountain area in the north effectively blocks the infiltration of cold air in the north, forming a downward airflow here. At the same time, the temperature in the basin is higher under the effect of "heat preservation".
In summer, however, Sichuan Basin is controlled by subtropical high belt, southwest monsoon and southeast monsoon alternately, which is easy to form warm shear (compared with a weather system of flow field, it is similar to warm front and belongs to one of the main precipitation weather systems), so there is more precipitation in Sichuan Basin in summer, and the temperature is also higher under the isolation of clouds and rain.
However, in the warm and humid environment of Sichuan Basin where "cold air can't get in and heat can't get out", this relatively warm and humid air has a natural maintenance effect on human skin, and mist and water vapor in the air can effectively weaken the influence of ultraviolet rays on human body, so Sichuan Basin is called "rich in beauty".
First of all, it rarely snows in most parts of the Sichuan Basin, but it may still snow at the edge of the basin, that is, in the mountainous areas with relatively high terrain. Generally speaking, due to the terrain, the temperature in Sichuan Basin is much higher than that in other areas of the same latitude, so it basically won't snow.
Sichuan Basin is the smallest of the four great basin in China. It is located in the center of China and the middle of the eastern edge of China. Surrounded by Qinghai-Tibet Plateau, Daba Mountain, Wushan Mountain, Dalou Mountain and Yunnan-Guizhou Plateau, there are Hengduan Mountains in the west, Qinling Mountains in the north, mountainous areas in western Hunan and Hubei in the east and Yunnan-Guizhou Plateau in the south. Then the high temperature in Sichuan basin is not limited to winter, but also relatively high on the whole. There are several reasons for the high temperature in Sichuan Basin:
Mountain Block: So there are two main reasons for the low temperature in winter in China. One is that the direct point of the sun moves south, which makes our solar radiation less and the temperature lower. Secondly, due to the thermal difference between land and sea, the cold air from Mongolia and Siberia blows from northwest to southeast in winter. Under the attack of cold air, the temperature in most parts of China will drop sharply. Then our Sichuan basin was blocked by the surrounding tall mountains, especially in the north, by the Qinling Mountains and Daba Mountain, so that the cold wind in winter could not reach the Sichuan basin, so the temperature was warmer.
Thermal insulation function of basin topography: The topography of Sichuan basin makes the interior of the basin produce concave mirror-like focusing effect after being irradiated by solar radiation, which partly increases the heat, while the other part makes the heat of concave topography difficult to spread. At the same time, the temperature rise makes the water vapor evaporate to form air mass. In the basin topography, the air is not easy to diffuse and the air mass is relatively stable. The stable air mass can increase the reverse radiation process of the atmosphere and make the atmosphere have the function of heat preservation, so the basin topography can make its temperature higher.
Therefore, the temperature in the basin is relatively high in winter, and the latitude in the Sichuan basin is not particularly high, so the probability of heavy snow is relatively small; In summer, topography and subtropical high control will make the basin very stuffy.
It snows, too, but not often.
Is this Xiao Xue? It will snow in Chengdu, too
In fact, in Suining, my hometown, it snowed several times in the past year, but because of the warmer weather, it snows less now and the four seasons are distinct.
Thanks to the double protection of Qinling Mountains and Daba Mountain, Sichuan Basin has become the warmest place at the same latitude in China in winter.