Typhoons are also called hurricanes. Typhoon is a tropical cyclone formed on the vast sea surface with tropical or subtropical sea surface temperature above 26℃. The foll
Typhoons are also called hurricanes. Typhoon is a tropical cyclone formed on the vast sea surface with tropical or subtropical sea surface temperature above 26℃. The following is the cause of typhoon that I sorted out for you. I hope it will be useful to you.
The cause of typhoon formation refers to the tropical cyclone formed on the vast sea surface above 26℃ in the tropics or subtropics. According to the definition of the World Meteorological Organization, a tropical cyclone with a central sustained wind speed of 12 to 13, that is, a tropical cyclone with a speed of 32.7m to 41.4m per second is a typhoon or a hurricane. The western part of the North Pacific, north of the equator, west of the international international date line and east of east longitude 100 degrees are usually called typhoons, while the North Atlantic and the East Pacific are generally called hurricanes. Every summer and autumn, there are many violent storms called typhoons in the northwest Pacific Ocean adjacent to China. Some will dissipate at sea, while others will land, bringing storms.
Typhoon originated in tropical ocean, where the temperature is high and a large amount of seawater is evaporated into the air, forming a low pressure center. With the change of air pressure and the movement of the earth itself, the inflow of air also rotates, forming a counterclockwise air vortex, which is a tropical cyclone. As long as the temperature does not drop, this tropical cyclone will get stronger and stronger, and finally a typhoon will form.
The gestation stage of typhoon life cycle
After a day of sun exposure, strong cumulonimbus clouds will form on the sea surface. The hot air in these cumulonimbus clouds rises, and the surrounding cold air is constantly replenished, and it rises again when it meets heat. This circulation makes the air above hot, the air below cold, and the evaporation of water vapor in the hot air above expands the scope of the cloud belt, making this movement more intense. Affected by the geostrophic force, the expanding cloud rotates counterclockwise and clockwise in the southern hemisphere, forming a tropical cyclone. The centrifugal force generated by the rotating air in the tropical cyclone throws the air outward, and the air in the center becomes thinner and thinner, and the pressure becomes smaller and smaller, forming the initial stage of tropical depression-typhoon.
Development enhancement stage
Because the air pressure in the tropical depression center is lower than that outside, the surrounding air rushes into the tropical depression and rises when it encounters heat, which provides more energy to the tropical depression, exceeding the output energy. At this time, the air in the tropical depression rotates more violently, the maximum wind force in the center increases, and the central air pressure further decreases. When the maximum wind force in the center reaches a certain standard, it will be upgraded to a higher level, tropical depression will be upgraded to tropical storm, then strong tropical storm and typhoon, and sometimes it will be upgraded to strong typhoon or even super typhoon, depending on the ratio of energy input and output. If the input energy is greater than the output energy, the typhoon will strengthen, and vice versa.
Mature stage
After a long road of development, typhoons have become powerful and capable of causing disasters. If we land at this time, it will cause great losses.
Extinction stage
A typhoon has two dead ends. The first one is that after the typhoon lands on land, it will weaken and die quickly due to the joint influence of ground friction and insufficient energy supply, and the residual cloud system after its death can bring heavy rainfall to a certain place for a long time. The second is that the typhoon turns in the northern part of the East China Sea, lands in South Korea or crosses the Korean Strait, then degenerates into an extratropical cyclone in the Sea of Japan, and then slowly dies out.
Typhoon 1 High Cloud Precursors: At the outermost edge of typhoon, there are cirrus clouds, white feathery or ponytail-shaped extremely high clouds. When such a cloud appears in a certain direction and gradually thickens into a dense cirrostratus, it indicates that there may be a typhoon approaching.
Thunderstorms stop: Thunderstorms often occur every afternoon in summer, mountainous areas and basin areas of Taiwan Province Province. If the thunderstorm stops suddenly, it means that a typhoon may be approaching.
3 Good visibility: 2 or 3 days before the typhoon, the visibility has improved, and trees in the distance can be seen clearly.
4 Land-sea breeze is not obvious: usually, the wind blows from the sea to the land during the day and from the land to the sea at night, which is called sea breeze and land breeze, but this phenomenon is not obvious a few days before the typhoon comes.
5. Long wave: In the offshore of Taiwan Province Province, the waves are relatively stable due to the mild summer monsoon. However, when there is a typhoon in the distance, the waves will become turbulent and gradually spread to the coast of Taiwan Province Province, resulting in long waves. Residents along the eastern coast have this experience.
6 hamming: as the typhoon approaches, the long wave is getting bigger and higher, hitting the coastal cliffs and making a roar, which is often heard on the eastern coast. After that, the typhoon will come in about 3 hours.
7 Sudden showers stop: When high clouds appear, the clouds become denser and lower, and showers often stop, which is also a sign that a typhoon is approaching.
Change of wind direction: Southwest wind is often blown in summer in Taiwan Province Province, which is also mild. However, if it is changed to northeast wind, it means that the typhoon is approaching and has begun to be affected by the edge of the typhoon, and then the wind speed will gradually increase.
9 Special sunset glow: Before the typhoon strikes 1 and 2 days, when the sun sets, several beautiful radial red and blue rays are often emitted from the western horizon to the zenith, and then converge in the symmetry between the east and the sun. This phenomenon is called anti-twilight.
10 air pressure decrease: According to the above phenomenon, if the air pressure decreases gradually again, it means that it will enter the typhoon edge.
Folk typhoon forecasting method 1 long wave: also known as surge. When the typhoon is far away from the ocean, you can see a special kind of waves spreading outward from the center of the typhoon at the seaside. The top of the wave is round, and the wave is not high, usually only one or two meters high. The wave spacing is long, which is different from ordinary spires and short-distance waves. Long wave looks * * *, with heavy sound and slow beat, and the speed is about 70-80 kilometers per hour. When this kind of wave is close to the coast, it will turn into rolling broken waves, which will often make the coastal water level rise and the waves surge. When you see this scene on the coast, and with the passage of time, the long wave is getting stronger and stronger, which shows that the typhoon is moving towards you.
Sea roar: Sea roar is also called sea sound or sea sound. Two or three days before the typhoon came, the roar of the sea could be heard along the coast. Its buzzing sound image is the sound of a distant plane, like the horn of a conch or the thunder in the distance, which is particularly clear and loud in a quiet night. When the sound gradually increases, it means that the typhoon is approaching; If the sound weakens, it means that the typhoon is gradually leaving. There is a cave facing the sea in Zhoushan Islands, Zhejiang Province. A few days before the typhoon comes, the sea will ring. Fishermen used this omen to take measures to prevent Taiwan, and the effect was good.
Mother 3: This is an experience of Fujian and other coastal fishermen in observing stations according to sky phenomena. When the typhoon center is about 500-600 kilometers away from the coast, coastal fishermen can see that bright clouds like silk are scattered on the eastern horizon, and they spread out from the horizon like fans. This is called convergence cirrus cloud in meteorology, which is about six or seven kilometers high. Beautiful rosy clouds will appear in the sky in the morning or at night. People call it "Mother Taiwan Province", which means that when they see this cloud, a typhoon is coming.
* * * Cable: Coastal fishermen are used to calling the light rays in the sky, that is, three or five blue stripes radiate upward from the eastern horizon across the sky, which is a wind cable. This is because there are many towering convective clouds in the typhoon area. When a typhoon approaches, sunlight is blocked by rows of cumulonimbus clouds near or below the horizon, and dark blue stripes appear in the sky. Sometimes, it will cross the sky, converge in the opposite direction to the sun, and soon disappear as the sun rises. So seeing the "wind cable" is also a sign that a typhoon is coming.
5 Broken Rainbow: There is a proverb among fishermen in the coastal areas of Fujian and Guangdong, "Now that the rainbow is broken, the sky will change". This "weather is going to change" means that typhoons will attack and bring storms. Broken rainbow, also known as short rainbow, is a semi-rainbow that appears on the southeast sea. It has no solitary bend of the common rain rainbow, and its color is not bright. It usually appears at dusk. Because the broken rainbow is formed by the low-altitude water droplets around the typhoon refracting sunlight, seeing the broken rainbow indicates that the typhoon is coming.
6 Wind direction: There are stories among fishermen, such as "one bucket of east wind and three buckets of rain" and "the north wind in June flooded the chicken coop". The proverbs "three fights of rain" and "soaking in a chicken coop" both refer to typhoon and rainstorm. This is because most typhoons come from the vast ocean in the southeast. When a place is affected by the external airflow in the first half of a typhoon, there are often three winds in the west, north and east, which last for half a day to more than one day and become a sign of a typhoon. This is also the meaning of the proverb "the east wind turns to the north, and there is a rope at home". But sometimes before the typhoon comes, some places are almost motionless, the sea is as calm as a mirror, and the moon shadow is clearly reflected on the sea, so there is a folk experience that "the seabed shines on the moon to dominate the wind". This gale was also caused by a typhoon.
7 jellyfish ears: jellyfish is one of the marine creatures that can hear infrasound waves generated between typhoons and waves. Infrasound with a frequency of 8- 13 Hz impacts the tiny otolith in the small ball on the slender handle of jellyfish. Neuroreceptors on the wall of the auditory stone "ball" So the jellyfish can vaguely hear the roar of the coming typhoon, so they leave the shore and swim to the sea to avoid being hit by the wind and waves. The forecaster is made by simulating the characteristics of jellyfish, which consists of a horn, a vibrator to receive infrasound waves, a piezoelectric transducer to convert vibration into electric pulses and an indicator. Install this instrument on the deck of the ship, and the horn rotates 360 degrees. When the rotation stops automatically, the direction pointed by the horn is the direction of the typhoon. The indicator shows the intensity of the storm brought by the typhoon.
Hydrogen balloon: Fishermen also have experience in measuring typhoons with hydrogen balloons. That is, if you put a balloon filled with hydrogen with a diameter of about 50 cm in your ear, you can know whether there is a typhoon in the distance and whether it will attack the local area. What is the reason? Because of the friction and impact between the peaks of strong winds and huge waves, low-frequency sound waves with a frequency of about 8- 13 Hz per second will be formed. This sound wave travels faster than wind and waves. Although people can't hear it directly, balloons filled with hydrogen can vibrate through low-frequency waves. The amplitude and intensity of this vibration will put pressure on the eardrum of people close to the hydrogen balloon, making the eardrum vibrate. The closer to the typhoon, the clearer this feeling will be. According to the change of clarity, it can be judged whether the typhoon is close or far away.