What are the meteorological wonders around the world?

The mystery of bamboo chair falling apart

Bamboo is abundant in southern China. Wooden articles for daily use in the north can almost be replaced by bamboo in the south. Generally speaking, there are bamboo tables, chairs, stools, coffee tables, recliners and so on.

These daily necessities made of bamboo are strong, beautiful, practical and cheap. Take the bamboo chair as an example. Solid and smooth, it feels cold and comfortable to sit on it in summer. Northerners sometimes bring back some bamboo products when they travel or visit relatives in the south.

But soon after returning to the north, especially in spring, these bamboo products changed: there were great cracks between bamboo pieces, bamboo needles fell out and sat on bamboo chairs, creaking, and after a long time, bamboo products fell apart and could not be used. Not only bamboo products, but also some wooden furniture transported from the south to the north will crack and deform.

It turns out that this is caused by different humidity. Not only the temperature and rainfall are different in different regions of China, but also the humidity of the air is very different. In southern China, there are many rainy days, heavy rainfall, dense lakes and ponds, vertical and horizontal rivers, paddy fields and high temperature, so the air has high water vapor content and high humidity. The moisture content in bamboo and wood materials will be higher correspondingly, and the furniture made under natural conditions also contains more moisture.

There is less rainfall in the north, less water surface in the fields, and the air humidity is inherently low. In spring, the sun is shining, the temperature rises sharply, and the evaporation is very large, but it is dry and rainy, so the air is very dry. Bamboo and wood furniture shipped from the south will shrink and deform due to the loss of water contained in it, or crack or fall apart and cannot be used.

A house built of ice and snow

Inuit people in Greenland and northern Canada cut the dense snow into large and thick snow bricks with long knives, and built a circular foundation with a diameter of about 3 meters on the foundation with snow bricks. People are standing inside, laying bricks layer by layer. When laying bricks to two or three floors, a door is opened on one side as a temporary passage. Each layer is shrunk a little, leaving only a small hole on the top. Finally, the small hole is blocked with snow bricks, and the small gap between bricks is sealed with broken snow. In order not to completely isolate the room from the outside world, they dug an underground passage and went in and out freely.

So, is the igloo as cold as the igloo? Can people freeze into popsicles in it? Of course not. It is much warmer indoors than outdoors. Because the igloo is completely closed, so tight that there is no gap, the cold air outside can't get in. The heat transfer of snow is very poor, and the snow brick with a thickness of 0.2 meters is a good heat insulation material, which makes it difficult to dissipate the heat in the snow house.

When travelers are numb by the cold wind, they will feel warm as soon as they step into the igloo. Some people light bonfires in the center of the igloo, which is even warmer than spring. If there is polar bear skin next to it, it is really more interesting for the whole family, old and young, to sit there and drink tea with a smile, just like sitting in a crystal palace. Because the outdoor temperature is tens of degrees below zero, the igloo will not melt even if the bonfire is burning.

Gunfire and rain came.

1one morning in June, 978, someone went to Robbie, Yunnan to collect animal specimens. 1 1 or so, Wan Li is clear and sunny. Suddenly, a deer ran out of the bush. The man quickly raised his shotgun and shot at the deer, which fell to the ground.

After three or four minutes, the whole mountainside was foggy, then it was dark, the wind roared, and then it rained cats and dogs. Then there were two gunshots, followed by fog and strong wind, and then it rained cats and dogs. Why?

In fact, the phenomenon of Robbie's "calling for rain" is related to the local topography and climate conditions.

June and July are Robbie's rainy seasons, and the air is wet and hot. These hot and humid air accumulated in the valley by the lake. But the top of the mountain is closed by snow and ice, and the air is dry and cold. Usually, hot and humid air and dry cold air live in peace here, but when the gunfire rang, sound waves echoed in the valley, and the sound waves that oscillated back and forth stirred the hot and humid air and dry cold air, and the two air masses with different properties mixed together and became thick black rolling clouds, followed by strong winds and then heavy rains.

Look at the rain on the other side

There is a very special village in Jiangnan Water Town, China. There is a river in the north and a river in the south of this village. In the afternoon, there was lightning and thunder near the village, and then it rained cats and dogs. At this time, people go out of their homes and stand outside watching the rain cross the river, never worrying that this thunderstorm will fall on their heads.

In fact, this is a cold lake effect. In midsummer, the degree of air heating is obviously different due to different topography. When sunlight reaches the bare ground, it is very easy to be reflected into the atmosphere, which makes the air temperature near the ground rise rapidly and become a heat source. Sunlight shines on the surface of rivers and lakes, and some of it is transmitted into the water, but less heat is reflected into the air, which becomes a cold source. This effect caused by the water surface is the cold lake effect.

The occurrence of thermal thunderstorm is caused by the rising of warm and humid airflow in the lower layer. On land, some places have high temperatures, which can continuously provide water vapor and updraft, and thermal thunderstorms always move in a certain direction due to the influence of low-level airflow.

Thunderstorm clouds encounter cold sources when they move on the water surface of rivers and lakes. Under the action of the cold lake, the air sinks, and the thunderstorm clouds can't get the support of rising and the transportation of water vapor, so they immediately weaken or even stop.

Because the north and south of the village are close to the water surface, the thunderstorm on the other side of the river is affected by the cold lake effect, and the thunderstorm cannot move over the village, so people can only watch the rain across the river.

A strange pool, the water level rises in dry season and drops in rainy season.

Deep in the Lashan rock mass in the west of Jinan, Shandong Province, there is a strange pool. The water level rises in the dry season and drops in the rainy season.

According to the director of the original Lashan Stone Factory who found the deep pool, this deep pool was built one year after the stone factory finished the last shot on the mountain. This pool is deep and unpredictable. According to the detection of 127 meters, the depth of the pool is still a mystery.

This pool has a large storage capacity. It pumped 7000 cubic meters of water from the pool within 72 hours, but the water level did not drop, but rose by 0.2 meters. What is even more surprising is that the water level of this pool rises in the dry season and falls in the rainy season. During the drought in March, the water level in the pool not only did not drop, but increased by 1 meter. During the rainy season in August and September, the water level dropped by nearly 2 meters. Although the drought continued this spring, the water level in the middle of the pool in March and April increased by 8 meters compared with last year's 65438+ 10.

Later, it was identified by the health and epidemic prevention department of Shandong Province that the pool water is dry and pure, sterile and tasteless, and contains many mineralized trace elements such as strontium, calcium and magnesium. Long-term drinking is beneficial to human liver, stomach, heart and kidney.

According to the analysis of geological and hydrological experts, the geological structure of this pool is the combination of granite and limestone intrusion, which was formed hundreds of millions of years ago. The water source stored in the pool is extremely weakly affected by the fluctuation of water level in the surrounding area. Then where such precious natural mineral water comes from, relevant departments are further studying.

A burning mountain with a dividing line between rain and sunshine.

People who have lived in the north of Taiwan Province Province for a long time will notice that the rainy days in winter are particularly long. However, in the south-central region, after entering 10 every year, it is always sunny until the rainy season comes the following year, and it is rare to have a few rainy days.

The climate difference between north and south is in sharp contrast. In winter, people who used to drive in expressway may have an experience. When the car goes from north to south, the sky is always so gloomy, especially in Miaoli area, which is often foggy. How can I tell, through so many clouds? . However, as soon as I crossed the flaming mountain and came down to Da 'anxi Bridge, the warm sunshine suddenly appeared, and another blue sky appeared in front of me, which made people feel cheerful.

Why is the weather so different just across a mountain? Because the thickness of the northeast monsoon of cold and humid air flow in winter is mostly below 2000m, it is blocked by the central mountains and snow-capped mountains in the northeast of Taiwan Province Province, which is a spent force in the area of Flame Mountain.

Unless the northeast monsoon is particularly deep, generally speaking, the low-level clouds and topographic precipitation generated on the windward side are not easy to cross the mountains and affect Taichung. Therefore, the Flame Mountain has become a natural dividing line, and the natural scenes in the south and north of the mountain are very different.

Arctic willow in the ice and snow

The earth in the Arctic is freezing. There is a particularly surprising Arctic willow growing here. Willow can be seen all over the world. It grows tall and majestic, and is a perennial woody plant.

The willow trees on the Arctic grassland, although woody, are very low and pitifully small, and can only grow close to the land, without even shrubs. Lu hung the weeping willow upside down, indicating that he had strength, and the willow roots were deep and leafy. But the willow trees in the Arctic will be uprooted, as easy as blowing off dust.

The climate in the Arctic is very special. Compared with other continents, it's windy and windy here. If the willow is a little longer, it will be blown down and can only crawl to the ground. Moreover, the ground is frozen, and the roots can't go down. They can only grow into clumps and look pathetic.

Invisible clouds

Scholars from the Institute of Atmospheric Optics of the Siberian Branch of the Soviet Academy of Sciences discovered an invisible cloud, also known as transparent cloud, over Central Asia, Siberia and the Far East of the Soviet Union.

This is the first time in the history of human atmospheric observation and research. It is said that the scholars of this institute observed the atmosphere over Siberia and the Far East by plane and found that Wan Li was clear and Wan Li was cloudless. But there is a clear cloud display on the screen of the cloud observation radar on the plane. After several years of continuous observation and testing, scholars have repeatedly encountered this invisible cloud over other areas.

1982, scholars encountered an invisible cloud while flying in Siberia. After determination, it was found that its area was 600 square kilometers and the thickness of clouds was 500 meters.

Zuev, director of the Institute of Atmospheric Optics, pointed out: Invisible clouds are made up of tiny molecules and hardly reflect sunlight, so people can't see them. These tiny molecules are mainly collected from dust particles produced by volcanic eruptions. Under the influence of high pressure, they generally form invisible clouds in the air from1200m to 3500m.

Interestingly, invisible clouds only exist in clear weather, and they are most easily caught at sunset. The length of invisible clouds is generally less than 40 kilometers, and the thickness of clouds is less than 100 meters. The research institute named this invisible cloud "medium-range suspended particle cloud". The mechanism of this cloud and its impact on the atmosphere are still under further study.