2005-12-31 Reads:656
"I have lived in Ya'an all my life, Ya'an rain is too deep feelings. All year round, Ya'an does not rain time to count on your fingers." Mr. Zhang, who lives in Ya'an, told the author that in October one year, it rained for 29 out of 31 days: "People were getting moldy during that time."
"There are four characteristics of rainy Ya'an," said Peng Guikang, a senior engineer at the Ya'an Meteorological Station, who has been studying the phenomenon of sky leakage. He introduced: "First, the number of days of rainfall, according to meteorological observation data statistics, 365 days a year, Ya'an heavy rainfall, sad and foggy rainy days will be as many as 218 days; the second is a large amount of rainfall, Ya'an average annual rainfall of more than 1,800 millimeters, rare in the Mainland; third is the number of hours of precipitation is long, precipitation throughout the year the cumulative number of hours up to 2,319 hours. "
Yaan rainy, there are two other notable features. Ya'an meteorological station senior engineer Mou Kequan told the author: first, more night rain. Ya'an rain more than 70% occurred at night, many times the rain from the night began to fall, daybreak that the clouds scattered rain, and night rain and more concentrated in the fall, especially in September and October each year; second is more rainstorms. Ya'an rainstorms generally occur in the summer, the average annual number of rainstorms in about 8 times, the most years of rainstorms reached 15 times.
What's puzzling is that with climate change and ecological degradation, it's raining less and less in many places. In other places shouting thirst, rain city known as Ya'an City, Sichuan Province, but the cloud abundance of rain, the sky leakage never stop. So, why is the rainy city "sky leakage"?
A legend --- Nuwawa mending the sky to leave hatred?
Why does the city leak? Every foreign tourist who has visited Ya'an has questions in his mind. "Feeling Ya'an rain is really amazing, I do not know how God will always rain in this place." A foreign tourist surnamed Li lamented.
Speaking of why the sky leaks, we heard a beautiful mythological legend in Ya'an: in ancient times, the sky was broken by the dragon, the founder of mankind, Nuwa refining colorful stones to mend the sky. When the sky elsewhere has been mended, only one side of the sky left in Ya'an, Nuwa has been exhausted, she reluctantly lifted the last colorful stone flying over Ya'an, a few efforts, and finally due to overwork fell in the Ya'an boundary, vomiting blood and died. From then on, Ya'an was covered by heavy rain, and Nuwa also turned into a mountain peak in the rainy city, watching over the blue waves of the Qingyi River in frustration.
Whether the legend is credible or not, Ya'an people on the human ancestor Nuwa's respect is witnessed, in Ya'an City, next to the Music Square, there stands a stone statue of Nuwa mending the heavens: Nuwa hands on the stone, looking up at the sky, a pose that is about to ascend to mending the heavens. "Although Nuwa didn't mend the sky in Ya'an, she died sobbing blood for mending the sky, so Ya'an people will always regard her as the patron saint of the rainy city." A Ya'an man of advanced years said so.
---Unveiling the sky leakage---
Mystery 1: Yucheng sky leakage is the role of several air currents with each other
"The rainy city sky leakage, in fact, is created by the special geographical environment in which Ya'an itself is located." Ya'an Meteorological Bureau senior engineer Peng Guikang told us. Since the early 1990s, Peng has been working with experts from the Institute of Atmospheric Physics of the Chinese Academy of Sciences to conduct a systematic study of the "Yucheng sky leakage".
He said, Ya'an's west side, is known as the roof of the world's Tibetan plateau, while the east is a thousand miles of the Sichuan basin. Ya'an is in the two different geomorphic environments, often by the plateau sinking airflow and the basin of warm and humid airflow interaction, coupled with the Indian Ocean from the south branch of the westerly winds hostage a large number of warm and humid airflow, often forced to move around the plateau east into the territory of Ya'an, which the interaction of airflow, resulting in not only the rainy days in Ya'an, the rain is long, and the rainfall is large.
He pointed to a topographical map of China for us to see. From the map, you can clearly see that Ya'an is in the gap between the plateau and the basin, even a layman can imagine: once the plateau and the basin over the air flow what "wind blowing grass", Ya'an will suffer from rainfall.
Riddle two: rain city sky leakage is Ya'an trumpet-shaped topography created
"Rain city sky leakage is another important reason, that is, Ya'an unique geographic shape created." Liu Zhengli, director of the Ya'an Meteorological Station, added that he has been engaged in forecasting for many years, and it is not difficult to realize that Yucheng is like a "little daughter-in-law" whose personal freedom is completely taken over by her "husband" and "in-laws" when she cast her eyes on the mountains surrounding Ya'an. "In-laws" control: its west is the tall and steep Erlang Mountain, the northwest is the treacherous Jiejianshan Mountain, the south and the Daxiangling Hengdan Xiang Xiang, only the east an exit.
This terrain consists of a horn shape, the east of the warm and humid airflow can only come in can not come out, a night, around the mountains of the cold airflow sinking, cold and warm airflow after the convergence of the rain city of this gas "little daughter-in-law" can only be in tears -----.
Mystery three: rain city sky leakage is the Pacific Ocean southward air flow conveying water vapor
In addition, Liu Zhengli also pointed out that: rain city sky leakage needs a lot of warm and humid moisture from the analysis of the atmospheric circulation situation, the atmospheric circulation for the Rainy City conveying water vapor has the Pacific Ocean sub-high and southward air flow. With their help, the "rainy city" of the sky so long leakage never stop.
Riddle 4: rain city sky leakage of the most fundamental reason or terrain
From the explanation of the two experts, "rain city sky leakage of the most fundamental reason or terrain factors, because with the Ya'an neighboring other areas of rainfall are not much, especially Erlangshan, Daxiangling that side of the luding and Hanyuan County, it is a world of difference in the climate with the Ya'an. " Liu Zhengli and Peng Guikang told us.
In order to confirm the fact that the experts said, after the interview, we that along the Sichuan-Tibet highway over the Erlang Mountain, the results were surprised to find: just a mountain, the east slope and the west slope of the climate, landforms, vegetation, soil and so on, but the world of difference. In the eastern slope of the foothills, the grass on both sides of the highway lush and luxuriant, primitive forests, lush, boundless, but the weather is really not to be commended, not heavy rain, or white fog. When the car over the pass, began to downhill, presented in front of the eyes is another world: the blue sky is boundless, the sun shines brightly, the clouds are white and flawless, the air is transparent and fresh, and can see the front into the clouds of the icebergs and snowy peaks, looking down on the earth at the foot of the land, it is to see the unevenness of the yellow earth is a desolate desolate, where the climate is dry, the hot wind blowing, the streams broke ---- Who would have thought that just a mountain, a mountain, a mountain and a mountain, a mountain and a mountain, a mountain and a mountain. --Who would have thought that the climate of the eastern and western slopes would be so different from that of the western slopes, just one mountain away?
Returning to Ya'an, we asked meteorologists to analyze this phenomenon. According to Liu Zhengli analysis, this phenomenon is related to the complex and peculiar topographic conditions: Erlangshan mountains in an orderly north-south direction, which puts its eastern slopes in the windward side, where a large number of warm and humid air due to the lifting effect of the condensation into raindrops down, so the eastern slopes of the rain is more; western slopes due to the blocking of the tall mountains, the warm and humid air in the crossing is almost lost, and across the mountains after the temperature will also be too high, resulting in the remaining Water vapor evaporation, coupled with the terrain along the western slope is closed, the temperature is higher, evaporation is vigorous, it is difficult to form clouds into rain, thus the climate along the western slope is dry and less rain. It seems that the rain city sky leakage, is indeed nature's ingenious work of art to create a unique geographic environment formed, just, similar to Ya'an such a geographic environment, unique in the world, so the world's rain city can only be Ya'an.
■Ya'an three best
Ya'an has "three best", national reputation: Ya'an rain, Ya'an fish and Ya'an women. Foreigners come to Ya'an, have to feel Ya'an three great: shower Ya'an rain, eat Ya'an fish, see Ya'an women.
"In terms of cause and effect, it is the Ya rain that creates the Ya fish and Ya women." Ya'an meteorological station director Liu Zhengli explained that because of the rain, so many rivers in Ya'an, the water quality is very good, basically not subject to any pollution, so the fish grown in the river tastes beautiful; also because of the rain, so Ya'an's sunshine correspondingly less, and the air is humid, the human skin has a very good protective effect, so Ya'an women are fair-skinned, grow very beautiful.
■Links
The sky leaks to create weather
In the rainy city, because the sky leaks a lot of rain, creating a lot of magical meteorological landscapes.
Ancient tree tears: in Ya'an Xingjing County, Taihu Temple, there will be an ancient tree will shed tears is also puzzling: the summer heat, the heat is unbearable, however, as long as people stand in the "tears" before the magical tree, immediately will be summer all away, cool and incomparable. According to a personal experience of the ancient tree Shi cool foreign tourists: this ancient tree is about 15 meters high, the trunk diameter of more than one meter, the whole tree shade about 20 square meters or so. From a distance, the tree branches and leaves, thick shade ramp, close to see the shape of the tree as a dragon flying, gnarled twigs twisted, rough bark such as scales, more curious is that the tree will drip from time to time large and small droplets of water, the summer days to this cool, and suddenly feel cool, the summer all go away; the hotter the weather, the tree will be dripping droplets of water and more and more big, the locals call this tree "will be shedding tears of the ancient tree! "
According to the report, it is said that the tree has been used for a long time.
According to meteorological experts, this is likely to be related to the Taihu Temple area of the climatic conditions: this place more rainy days, humidity, the ancient tree has long been full of rain and dew moisturizing, the trunk of the tree naturally accumulated sufficient water. Cloudy and rainy weather, because the humidity in the air is saturated, the water within the tree by the outside world saturated state of the "block", generally will not overflow; once the weather clears, the humidity in the air to small, the water pressure within the tree is greater than the outside world resistance, the water will be seeping out. Of course, the ancient tree of this "tears" phenomenon, with its own rough bark, the trunk is very easy to store water is closely related.
Spraying fish signs of wind and rain: In addition, due to the sky leakage of the mysterious meteorological landscape, there are "spraying fish signs of wind and rain". Zhougong River in Ya'an, whenever the weather turns bad, before the storm, there will be a "grouper" from hiding in the cave trolling out, scrambling to jump out of the water, the fish jumping like a cave spouting fish, according to the locals, "spouting fish" phenomenon occurs Late, there are generally windy and rainy weather. Meteorological experts analyze this phenomenon is caused by changes in atmospheric pressure: before the storm, the air pressure in the atmosphere is reduced, resulting in insufficient oxygen in the water, the air is very hot and stuffy, the fish in the cave breathing difficulties, they will defiantly jump out of the water to relieve boredom.
Author: Wen/Jiang Yongyu Article source: Science and Technology Daily (2005.12.29)