Anti-cyclone detailed data collection

Anti-cyclone refers to the horizontal air vortex with the central air pressure higher than the surrounding air pressure, and it is also the high pressure in the air pressure system. The anticyclone in the northern hemisphere, the horizontal airflow in the lower layer diverges clockwise, and the anticyclone in the southern hemisphere diverges counterclockwise. The horizontal scale of anticyclone is greater than that of cyclone. For example, the Mongolian-Siberian high in winter occupies 1/4 of Eurasia. The air pressure in the center of each anticyclone is generally around 1020 ~ 1060 HPA, and the highest air pressure recorded is110/.6 HPA. The wind speed in the anticyclone is small, and the maximum wind speed on the ground is only 20 ~ 30m/s, and the wind force in the central area is weak. Controlled by anticyclone, the weather is sunny most of the time.

The air pressure in the anticyclone center is the highest, and gradually decreases outward. In the northern hemisphere, the air in the anticyclone area flows clockwise. Its diameter ranges from several hundred kilometers to five or six thousand kilometers, such as Mongolia-Siberia high in winter and subtropical high over the Pacific Ocean in summer. When the air in the anticyclone spreads around, it forms a downward airflow. Therefore, when the anticyclone controls the city, the weather is generally better. It is sunny and cold in winter, sunny and hot in summer, windy in spring and autumn and crisp in autumn.

Chinese name: anticyclone mbth: anticyclone, also known as: high pressure feature: central pressure is higher than surrounding pressure type: horizontal air vortex northern hemisphere: low-level horizontal airflow is clockwise southern hemisphere: anticlockwise outward feature, intensity classification, anticyclone intensity, anticyclone classification, type, distribution, related knowledge, cold wave, cold wave invasion path, cold wave influence, influence range, cyclone, terminology and characteristics: anticyclone means that the central pressure is higher than its surroundings. The names of cyclone and anticyclone come from the large airflow field, and the names of high pressure and low pressure come from the pressure field. The size of cyclone and anticyclone is measured by the range of the outermost closed isobar on the ground map. The horizontal scale of a cyclone is generally 1000km, the largest can reach 2000-3000km, and the smallest is only 200-300 km. The horizontal scale of anticyclone is generally much larger than that of cyclone. When it is strong, it can reach several Qian Qian meters. The intensity of cyclone and anticyclone is expressed by the central pressure value. The lower the air pressure in the cyclone center, the greater the intensity. The higher the air pressure in the anticyclone center, the greater the intensity. Generally, the air pressure at the center of surface cyclone is10/0-970 hectopascals, which is lower than 935 hectopascals in strong development and as low as 920 hectopascals in the ocean. Generally, the air pressure at the center of the surface anticyclone is 1020- 1030 hectopascals, and the strong anticyclone can reach 1079. 1 hectopascals. In the northern hemisphere, the air in cyclone rotates counterclockwise around the center, and the air in anticyclone rotates clockwise around the center. In the southern hemisphere, the airflow is the opposite. Cyclones are divided into temperate cyclones and tropical cyclones according to the occurrence area, and anticyclones are divided into polar anticyclones, temperate anticyclones and subtropical anticyclones. Cyclone and anticyclone are two important weather systems that cause weather changes. Temperate cyclones and anticyclones occur in middle and high latitudes, accompanied by high-altitude front areas. Their occurrence, development and movement are closely related to the upper-air weather system. In the low-pressure atmosphere, especially near the ground, because the anticyclone airflow flows outward from the center. Therefore, there must be downward airflow in the center of the anticyclone to supplement the air flowing around. Otherwise, anticyclone cannot exist and develop. Therefore, the existence and development of anticyclone must have a complete circulation system which is closely combined with vertical movement and horizontal movement. Because the center of anticyclone is downdraft, it is not conducive to the formation of clouds and rain. Therefore, the weather under the control of anticyclone is generally clear and cloudless. If it is in summer, the weather is hot and dry. If the anticyclone is stable and inactive for a long time, drought will often occur. The summer drought in the Yangtze River basin in China is caused by the long-term control of subtropical high. In winter, anticyclone comes from high latitude continent, which often brings dry and cold air flow, and can turn into cold current in severe cases. Intensity classification The intensity of an anticyclone varies. Its strength can be measured by its maximum wind speed: the maximum wind speed is strong and the maximum wind speed is small. In a strong anticyclone, the maximum wind speed on the ground is 20-30m/s. The central pressure value of an anticyclone is often used to indicate its intensity. The central pressure of surface anticyclone is generally 1020-l030 mbar, and the highest cold wave pressure in winter is above 1078.9 mbar. Classification of anticyclones There are many methods to classify anticyclones. According to geographical location, anticyclone can be divided into temperate anticyclone, subtropical anticyclone and polar anticyclone. According to different structures, anticyclone can be divided into cold anticyclone (or cold high pressure) and warm anticyclone (or warm high pressure). There is no insurmountable gap between cyclones. Different types of cyclones and anticyclones; Under certain conditions, they will transform into each other. For example, frontal cyclone can be transformed into frontal cyclone (cold vortex) under certain conditions, and frontal cyclone (hot low pressure) can be transformed into frontal cyclone under certain conditions; Cold anticyclone can also be transformed into warm anticyclone. Cyclone and anticyclone should be regarded as conditional, variable and mutually transformed. The types of anticyclones are divided into cold anticyclones (cold high pressure) and warm anticyclones (warm high pressure) according to their structures. The intensity of cold high pressure (such as Siberian high pressure) is usually weak at a height of 3 ~ 4 kilometers, while warm high pressure (such as subtropical high pressure) is a deep system that can reach the tropopause. According to geographical location, anticyclone can be divided into temperate anticyclone, subtropical anticyclone and polar anticyclone. According to the structure of anticyclone, it can be divided into cold anticyclone (cold high pressure) and warm anticyclone (warm high pressure). Cold anticyclone and cold wave in temperate zone during the winter half year, the continental surface is cooled by intense radiation, and air gathers on the continent to form cold high pressure. The Mongolian-Siberian high located in Eurasia in winter is the most powerful and influential cold high in the world, which affects Italy in Central Europe in the west and Nansha Islands in China in the southeast, causing strong winds and cooling weather in the passing area. Rainfall and/or snowfall occurs where the cold air front meets the warm air, and the main body of cold and high pressure reaches the area to maintain sunny and hot weather. Anti-cyclone temperate anti-cyclone temperate anti-cyclone refers to the anti-cyclone active in the middle and high latitudes. Generally, it can be divided into two categories: one is a relatively stable cold anticyclone; The other is an anticyclone that moves with the frontal cyclone, which is called a moving anticyclone. Cold anticyclones and cold anticyclones occur in extremely cold mid-latitude and high-latitude areas, such as Greenland, Canada, the Arctic, Siberia and Mongolia in the northern hemisphere, and are most common in winter. Its powerful force and wide influence often cause cooling, strong wind and precipitation in the active area, which is the most prominent weather process in winter in the middle and high latitudes. Cold anticyclone appears in the surface layer, which is composed of cold air and is very powerful. The central air pressure reaches 1030- 1040 hectopascals, and reaches 1080 hectopascals when it is strong. According to the principle of statics, it weakens with height and becomes a cold low pressure area at high altitude, so the cold high pressure is a shallow weather system with an average thickness of less than 3-4 km, and the trace above 700hPa is unclear, and above 500hPa does not exist at all. The horizontal range of cold anticyclone is very large, with a diameter of several Qian Qian meters, which can almost be compared with the area of mainland and ocean. The Asian continent has a vast territory, and the winter temperature in the north is very low. The Qinghai-Tibet Plateau in the south and the east-west mountains block the cold air from going south, making it the most frequent and powerful area of cold anticyclone activity in the northern hemisphere. Cold anticyclone is usually stationary and seldom moves during its development strengthening period, but it will move under the guidance of high-altitude airflow when the high-altitude situation changes. When it moves south, it will cause cold air to attack. If the cold air is very strong, like a cold wave rolling in, it will cause severe weather such as severe cooling, frost and strong wind. This large-scale strong cold air activity is called cold wave. According to the National Meteorological Administration of China, when the temperature drops above 10℃ and the lowest temperature drops below 5℃ within 24 hours due to the invasion of cold air, it is the standard for issuing cold wave warning. However, in terms of harmfulness, this standard is slightly higher, especially the lowest temperature in the south often does not drop below 5℃, which will cause great harm to crops. At the same time, this regulation does not specify the temperature drop range of 65438 00℃. Therefore, the National Meteorological Administration has made supplementary provisions for the above standards: the temperature in the middle and lower reaches of the Yangtze River and its northern area will drop above 10℃ within 48 hours, and the lowest temperature in the middle and lower reaches of the Yangtze River will be lower than 4℃ (the lowest temperature in spring and autumn in Jianghuai area will be lower than 4℃). Strong winds of magnitude 5 or above occurred in the three administrative regions on land, and strong winds of magnitude 7 or above occurred in Bohai Sea, Yellow Sea and East China Sea one after another, which was regarded as the early warning standard of cold wave. If the temperature drops 14℃ or above within 48 hours in the above areas, the rest are the same as above, which is the early warning standard of strong cold wave. According to the above statistics, there are 195 1- 1976 cold waves in China, with an average of about 5 times a year. Cold wave mainly occurs in11-April, with more in late autumn, early winter and early spring, but less in the middle of winter, mainly because the definition of cold wave only considers the cooling range. Spring and autumn are a period of large-scale average circulation adjustment, and cold and warm air alternate frequently, so there are more cold air activities. In winter, cold air is absolutely dominant in most parts of China, the weather situation is stable, and cold air activities are relatively reduced. In summer, cold air retreats to high latitudes, which rarely affects our country. The frequency of cold waves varies from year to year. Take China as an example, the average frequency of 1965- 1966 and 1968- 1969 is 10, while 1974- 1975. In the late 1960 s, it averaged 7 times a year, and in the early 1970 s, it averaged only 3 times a year, which was very different. Subtropical high and Meiyu are subtropical high areas within the latitude of 25 ~ 35 in the northern and southern hemispheres. Due to the different land and sea distribution and topography, the subtropical high fault is divided into several closed centers, that is, subtropical high. In summer, the subtropical high zone in the northern hemisphere is divided into: East Pacific high, West Pacific high, North Africa high and North Atlantic high. In winter, there are: North Pacific High, North Atlantic High and North Africa High. Subtropical high is strong in summer and weak in winter, and big in summer and small in winter. Subtropical high is a stable, quiet and extremely deep warm high with a wide range of downdraft. Under its control, the weather is fine. The eastern part of China lies to the west of the subtropical high in the North Pacific. In summer, it gradually spreads to the west and north, and transports water vapor to the east of China with the southeast wind, which is one of the important sources of precipitation in the east of China, and the summer rainstorm in Jianghuai basin is closely related to it. In midsummer, if the subtropical ridge extends to the Jianghuai area, the downward airflow on the ridge makes it difficult for water vapor to condense into clouds, and it is replaced by hot, dry and rainless summer weather. In winter, the subtropical high in the North Pacific shrinks towards Hawaii, which has little influence on the weather and climate in China. Similar to the phenomenon in eastern China, it will also occur in the eastern United States and the east coast of other continents in subtropical latitudes. On the left is an area controlled by subtropical high all the year round on the anticyclone continent. The climate is extremely dry, forming a world-famous desert, such as the Sahara desert in Africa. The distribution path of anticyclone is not as clear as cyclone. Because the air sinks at 25 ~ 30 north latitude and spreads near the ground to form an anticyclone, there is a subtropical anticyclone in the ocean all the year round. On the mainland, subtropical high often develops well in winter; In summer, due to the high temperature, various monsoons and anticyclone belts break. Related knowledge Cold wave Cold wave is a kind of disastrous weather in winter, and people are used to calling it cold wave. The so-called cold wave is a weather process in which cold air from the north invades China on a large scale, resulting in a large-scale sharp cooling and northerly winds. Cold waves generally occur in late autumn, winter and early spring. According to the regulations of China's meteorological department, if the temperature drop caused by cold air intrusion reaches more than 10℃ and the lowest temperature is lower than 5℃ in one day, it is called a cold wave process. It can be seen that not every cold air heading south is called a cold wave. In the Arctic, due to the weak sunlight, the ground and the atmosphere get less heat, and it snows all year round. In winter, the direct sunlight passes through the equator and reaches the southern hemisphere. The arctic region is colder and wider, and the temperature is generally below MINUS 40℃-50℃. Large-scale cold air masses gather to a certain extent, and under the action of suitable high-altitude circulation, they will invade southward on a large scale, forming cold wave weather. The anticyclone China is located in the southeast of Eurasia. From our country to the north are Mongolia and Siberia in Russia. Siberia is a very cold place. If you continue to go north, you will reach the northernmost part of the earth-the North Pole. It is colder than Siberia, and the cold period is longer. The cold wave that affected our country was formed from those places. Located in the Arctic at high latitudes, Siberia and the Mongolian Plateau, the ground rarely receives the heat of the sun all year round. Especially in winter, when the sun moves south, the angle of the sun in the northern hemisphere becomes smaller and smaller. So the ground absorbs less and less sunlight heat, and the surface temperature becomes very low. In the Arctic Ocean in winter, the temperature is often below -20℃, and the lowest can reach -60℃-70℃. 5438+ 10 The average temperature in June is often below -40℃. Because the temperature in the Arctic and Siberia is very low, the density of the atmosphere will increase greatly, and the air will continue to shrink and sink, increasing the pressure. This will form a strong, deep and broad cold and high-pressure air mass. When the strength of this cold high pressure increases to a certain extent, it will surge like a tide that has burst its banks. This is the cold wave. After each anticyclone cold wave, the cold air in Siberia will decrease and the air pressure will also decrease. But after a while, the cold air gathered again and piled up, gestating a new cold wave outbreak. According to statistics, about 95% of cold air passes through central Siberia (70 ~ 90 E, 43 ~ 65 N) and accumulates there. This area is called the key area of cold wave. There are four main routes to invade China from key areas: (1) Northwest Road (Middle Road) Cold air from key areas passes through Mongolia, goes south near the Hetao in China, and reaches the middle and lower reaches of the Yangtze River and the south of the Yangtze River. The cold air coming down this route, the cold wave weather north of the Yangtze River is mainly northerly wind and cooling. After reaching the south of the Yangtze River, it may develop with rain and snow due to the active fluctuation of the south branch. (2) The cold air on the East Road passes through Mongolia to the north of North China. While the main cold air continues to move eastward, the low-altitude cold air turns to the southwest, invades North China through the Bohai Sea, and then reaches the two lake basins from the lower reaches of the Yellow River. The cold air coming down this route often causes strong winds in the northeast of the Bohai Sea, the Yellow Sea, the lower reaches of the Yellow River and the lower reaches of the Yangtze River, backflow in North China and East China, low temperature and even rainy and snowy weather. (3) The cold air on the west road flows southward from key areas through Xinjiang, Qinghai and the southeast of Qinghai-Tibet Plateau, which has a great influence on the northwest, southwest and south of China, but the cooling rate is not great. However, when the fluctuation of the south branch and the fluctuation of the north branch overlap, it can also cause obvious cooling. (4) East Road, Jiaxi Road, the cold air of East Road goes south from the lower reaches of Hetao, and the cold air of West Road goes south from the southeast of Qinghai. Two cold air often meet on the east side of the Loess Plateau, between the Yellow River and the Yangtze River, causing a wide range of rain and snow, and then the two cold air meet south, causing strong winds and obvious cooling. The influence of cold wave The gale and cooling weather brought by cold wave and strong cold air are the main disastrous weather in winter half a year in China. Cold waves and strong winds are a great threat to coastal areas, such as the cold wave on April 2 1 ~ 25, 1969. Strong winds hit the Bohai Sea, the Yellow Sea and Hebei, Shandong, Henan and other provinces, with land winds of 7 ~ 8 and offshore winds of 8 ~ 10. At this time, it was the astronomical tide, and the outbreak of cold wave caused the rare storm surge in Bohai Bay and Laizhou Bay for decades. On the northern shore of Shandong Province, the sea water rose by more than 3 meters, washed away the seawall by more than 50 kilometers, and the sea water flowed backwards for 30 ~ 40 kilometers. The freezing rain, snow and ice weather brought by the cold wave is extremely harmful to transportation. For example, 1987 1 1 A cold wave process in the last ten days caused the turnouts of several stations under the jurisdiction of Harbin, Shenyang, Beijing and Urumqi to freeze, the tracks were buried by snow, the communication signals failed, and the train operation was blocked. After the rain and snow, the roads were frozen and skidded, and traffic accidents increased obviously. Cold wave is very harmful to human health. The windy and cool weather can easily lead to colds, tracheitis, coronary heart disease, cor pulmonale, stroke, asthma, myocardial infarction, angina pectoris, migraine and other diseases, and sometimes make patients worse. The strong wind and cooling weather brought by the cold wave have a great influence on ship transportation. In order to protect the safety of ships, crew and passengers, some preventive measures should be taken. Strong winds and heavy snow will reduce visibility, make it difficult for ships to operate, cause serious deflection and deviation, and pose a threat to the safety of ships. Therefore, according to their respective wind resistance, ships should choose safe places to anchor and tie the wind in time, display signals and acoustic signals according to regulations, and take various safety measures; Snow and ice should be cleared in time, and anti-skid mats should be laid on decks, aisles and springboard to avoid industrial accidents; Wrap the pen tube of the rafter with thermal insulation material and drain the remaining water. Prevent freezing in the pipe and cracking of the pipe wall. In the northern rivers, as long as the ships are ready to dock in winter, they can prevent the ships from freezing in the channel. Few people mention that the cold wave also has beneficial effects. The research and analysis of geographers show that the cold wave contributes to the heat exchange on the earth's surface. With the increase of latitude, the energy received by the earth from solar radiation gradually weakened, so the earth formed tropical, temperate and cold zones. The cold wave injects a lot of cold air into tropical areas, which makes large-scale heat exchange on the ground, which is very helpful to maintain the ecological balance of nature and maintain the lush species. Meteorologists believe that the cold wave is the guarantee of good weather. China is affected by monsoon, and the winter climate is dry, which is a dry season. However, whenever the cold wave invades the south, it will often bring a wide range of rain and snow weather, alleviate the winter drought and benefit crops. Why can the agricultural proverb "Xue Ruizhao has a good year" be circulated among the people for generations? This is because snow water has a high nitrogen content, which is more than five times that of ordinary water, and can greatly increase the nitrogen in the soil. Snow water can also accelerate the decomposition of soil organic matter, thus increasing the organic fertilizer in the soil. The heavy snow covered the overwintering crops and played the role of a quilt, keeping out the cold and keeping warm. There is a saying that "winter is not cold, and the coming year is not abundant", which also has its scientific truth. Experts in crop pest control believe that the low temperature brought by the cold wave is the most effective natural "insecticide" at present, which can kill a large number of pests and germs lurking in the soil for the winter, or inhibit their reproduction and reduce pests and diseases in the coming year. According to the survey data of agricultural technology stations around the country, pesticides can be saved by more than 60% in the year of heavy snow and winter closure. Anti-cyclone cold waves can also bring wind resources. Scientists believe that wind is a valuable energy source without pollution. The power generation efficiency of the world-famous Miyakojima wind power station during the cold wave is 1.5 times that of the usual one. Its east-west length can reach several hundred kilometers to several Qian Qian meters, but its thickness is generally only two or three kilometers. The moving speed of the cold wave is tens of thousands of meters per hour, which is similar to the speed of the train. There are three routes that affect the cold wave in China: one is the west road. This is the earliest and most frequent route in China. Strong cold air starts from the Arctic, goes south through western Siberia, enters China and Xinjiang, and then invades North China, Central Plains, South China and even Southwest China along the Hexi Corridor. The second is the middle road. Strong cold air flows from Lake Baikal in Siberia and the People's Republic of Mongolia, passes through Inner Mongolia Autonomous Region, enters North China and reaches the southeast coastal areas. The third road is East Road. Cold air flows south from the northeast of Siberia, sometimes through the northeast of China, sometimes through the Sea of Japan and the Korean Peninsula, and invades the eastern coast of China. The main force of the cold wave going south from this route is eastward, which is generally not very strong and the frequency will not be too much. Characteristics Cold wave outbreaks have different characteristics in different geographical environments. In the northwest desert and loess plateau, it is characterized by less wind and snow, which is easy to cause sandstorm weather. In Inner Mongolia grassland, it is windy, snowy and cold. In North China and Huanghuai areas, cold waves are often accompanied by snow and snow. In the northeast, it shows more violent winds and heavy snow, and the snowfall is the highest in the country. Jiangnan is often accompanied by freezing rain. To prevent cold wave, weather forecast should be strengthened, and accurate cold wave information or early warning of anticyclone 1 should be released in advance. When the temperature drops suddenly, you should pay attention to adding clothes to keep warm, especially the hands and face. 2. Close the doors and windows and fix the outdoor structure. Be careful when you go out. 4. The old, the weak, the sick and the disabled, especially those who are sensitive to temperature changes such as cardiovascular patients and asthma patients, should try not to go out. 5. Pay attention to rest and don't be overtired. 6. Beware of gas poisoning, especially for families that use coal stoves for heating. In the northern (southern) hemisphere of the cyclone, the horizontal airflow in the atmosphere is a large vortex rotating counterclockwise. The northern hemisphere leans to the right, and vice versa. At the same height, the air pressure in the center of the cyclone is lower than that around it, which is also called low pressure. Cyclones are similar to circles or ellipses, and their sizes vary greatly. Small cyclones have a horizontal scale of several hundred kilometers, and large ones can reach three or four thousand kilometers. In cyclones, the weather often changes dramatically, which is the weather system that people are most concerned about and studied at the earliest. Usually classified according to the main areas or thermal structures where cyclones are formed and active. According to the region, it can be divided into temperate cyclone, tropical cyclone and polar cyclone vortex According to the thermal structure, it can be divided into cold air rotation and hot low pressure. There are vortex motions in the atmosphere similar to those in rivers, and there are two kinds of rotating motions: clockwise and counterclockwise: cyclone and anticyclone, both of which are large horizontal vortex motions in the atmosphere. Cyclone, in the northern hemisphere, the air moves counterclockwise, the central air pressure is the lowest, and it gradually increases outward, and the air continuously flows into the center, forming an updraft, also known as low air pressure. Its diameter: tens of kilometers small, thousands of kilometers big. When affected by hurricanes, rainy weather and strong winds often occur. There are all kinds of eddies in the atmosphere, some rotate counterclockwise and some rotate clockwise. Among them, the larger horizontal vortex is called cyclone and anticyclone respectively, that is, low pressure and high pressure. Cyclone term cyclone: Cyclone is also called low-pressure cyclone. A large vortex that occupies three-dimensional space and has a closed isobaric (high) line at the same height (isobaric surface) and the central pressure (height) is lower than the surrounding pressure (height). In the northern hemisphere, air rotates counterclockwise; In the southern hemisphere, it rotates in the opposite direction: anticyclone, also known as high pressure. Cyclone and anticyclone are two aspects of a system. Jianghuai cyclone: refers to the cyclone in Jianghuai area now. Northeast cyclone: also known as northeast depression. Cyclone active in northeast China. It is one of the important weather systems affecting China. Anti-cyclone frontal cyclone: also known as polar front cyclone, wave cyclone and baroclinic cyclone. Strong fluctuation baroclinic cyclone produced in the development of temperate polar front. In China, there are frontal cyclones entering trough, shallow depression or typhoon. Cold vortex: short for cold vortex. The vortex strength with the center temperature lower than the ambient temperature increases with the height. Northeast Cold Vortex: A large-scale cold vortex moving at high altitude in or near the northeast of China. It is a deep system that can last for 3-4 days or longer. Southwest vortex: also known as southwest vortex. Under the combined action of special topography and certain circulation in the Qinghai-Tibet Plateau and southwest China, a shallow vortex is generated at low altitude in southwest China.