The subtropical high, or "subtropical high" for short, lies between the tropical and temperate zonesSubtropical zoneThere is a high pressure belt in the area.Existing on subtropical high beltArid zoneAgainThe world has the most abundant rainfallOfMonsoon region, makeSubtropical zoneIt has become the zone with the most changeable weather and climate and the most frequent floods, floods and droughts in the world.The subtropical high pressure zone exists all the year round and is a stable and less dynamic warm deep system.In summer, it covers an area of almost 1/5 to 1/4 of the entire Northern Hemisphere, with great intensity.However, in winter, its strength and scope will become smaller.[5-6]
The subtropical high pressure zone is mainly located in Chinasouth China、Jiangnan、Yangtze and Huai rivers、Huanghuai RiverAnd other eastern monsoon regions.In its heyday, its power also expanded to the east of southwest China and the southeast of northwest China.The deputy high is a "great director" with a strong personality,rain beltChangeshigh temperatureThe duration oftyphoonMost weather changes are inseparable from the trend of.[8]
The location of the main rain belt can be roughly determined according to the northward movement and southward movement of the "subtropical high": from the first ten days of May to the last ten days of June every year in the Gregorian calendar, the location of the "subtropical high" is about 15 ° to 20 ° north latitude, and the rain belt is usually located in southern China;From mid June to late July, the "subtropical high" extends westward and northward to 20 ° to 25 ° north latitude, and the rain belt also moves northward to the middle and lower reaches of the Yangtze River to southern Japan, forming a plum rain season lasting one month;From July to August, the "subtropical high" further moved northward to 25 ° to 30 ° north latitude, pushing the rain belt northward to North China and Northeast China;In September, the "subtropical high" gradually retreated to the south.[6]
Chinese name
Subtropical high pressure zone
Foreign name
Subtropical high pressure belt
Alias
Subtropical high belt
Location
Located in the subtropical area near 20-30 ° north south latitude
The subtropical high zone refers to the existence of a high pressure zone in the subtropical area between the tropical and temperate zones, which is often called the "subtropical high".The subtropical high belt is an arid belt around the world, concentrating most of the desert areas in the world.However, this arid zone is dotted with several monsoon regions with the most abundant rainfall in the world, making the subtropical zone the zone with the most changeable weather and climate and the most frequent floods and droughts in the world.[5]
The "subtropical high" plays an important role in the transport and balance of water vapor, heat and energy between the middle and high latitudes and the low latitudes, and is an important system of atmospheric circulation.The eastern part of the subtropical high is a strong subsidence movement area, and the subsidence flow warms up due to adiabatic compression, and there will be continuous sunny and hot weather in the controlled area.The western part of the subtropical high is the area where the warm and humid air at the lower level converges and rises, which is prone to thunderstorms.With the change of seasons, the intensity and position of the subtropical high belt will also have obvious seasonal changes.[7]
The downdraft prevails in the subtropical high pressure zone, and the air temperature increases strongly;However, due to the small pressure gradient, the wind is very small.In this state, the solar radiation can reach the ground more, making the ground and near ground atmosphere get more heat, and the atmospheric temperature rises significantly.Therefore, the areas under the control of the "subtropical high" are often sunny and cloudless hot weather, and even bring drought.In addition, the location change of the "subtropical high" is closely related to the distribution of the main rain belt in China.The southwest air flow located at the northwest side of the high ridge of the "subtropical high" is an important channel to transport water vapor to the rain area, while the easterly belt located at the south side of the "subtropical high" is an active area of the tropical precipitation system.[6]
Generally speaking, people can roughly determine the location of the main rain belt according to the northward movement and southward retreat of the "subtropical high": from early May to late June, the location of the "subtropical high" is about 15 ° to 20 ° north latitude, and the rain belt is usually located in ChinaSouth China ；From mid June to late July, the "subtropical high" extends westward and northward to 20 ° to 25 ° north latitude, and the rain belt also moves northwardMiddle and lower reaches of the Yangtze RiverTo the south of Japan, forming a month long plum rain season;From July to August, the "subtropical high" further moved northward to 25 ° to 30 ° north latitude, pushing the rain belt northward to ChinaNorth China、northeastRegion;In September, as the "subtropical high" gradually retreats to the south, the rain belt also moves to the south, and the rainy season in northern China ends.[6]
In summer, "subtropical high" and typhoon restrict and influence each other.When the "subtropical high" is east-west banded and its intensity is stable, the typhoon located at the south side of the "subtropical high" will move westward and its path will be stable;If the intensity of the "subtropical high" is not enough, when the typhoon moves to the southwest of the "subtropical high", it will force the "subtropical high" to retreat to the east, and the typhoon may therefore turn to move northward;In addition, typhoons sometimes break the "subtropical high" when it is "weak" and pass through it.Of course, there are many factors affecting the direction of typhoon, and the "subtropical high" is just one of them.[6]
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Subtropical high pressure zone (Figure 3)
The subtropical high lies between the tropics and the temperate zone. It is usually called the Pacific subtropical high, which controls the Pacific region.It varies with seasons and generally moves between 10 and 40 ° N.[7]In summer, under the control of the subtropical high, the air flow subsides, resulting in drought and little rain.In winter, the subtropical high moves to low latitudes, and the westerlies in this climate zone have frequent cyclones with abundant precipitation. At the same time, the westerlies move from the warmer ocean in winter（Differences in thermal properties between land and sea）The weather is mild and humid.
The "subtropical high" is a high pressure system located in the subtropical region (latitude is about 20 °~30 °).It is oval in shape and its long axis is roughly parallel to the weft circle. It is a warm dynamic system, which is generally most obvious on the 700 hPa and 500 hPa isobaric mapsPlanetary scale system(See weather system).Subtropical highIt plays an important role in the transport and balance of water vapor, heat, energy and angular momentum between middle and high latitudes and low latitudes, and is an important system of atmospheric circulation.The subtropical high is mainly located on the ocean and exists all the year round. It is called the North Pacific HighNorth Atlantic HighSouth Pacific High, South Atlantic High and South Indian Ocean High.Since these high pressures surround the whole subtropical region, they are collectively calledSubtropical high belt。Sometimes, the subtropical high can also split into smaller high-pressure cells, and some small cells can also be located on the mainland.The monomer located in the South China Sea in winter is called the South China Sea High.
As far as the individual subtropical high is concerned, there is a great difference in the vertical movement of the atmosphere in the east and west: in the east of the high pressure, the downward movement is particularly strong, and the downward flow warms up due to adiabatic compression, resulting in a strong downward inversion, which is called trade wind inversion.This strong inversion stratification is very stable (seestatic stability of atmosphere , inhibited the development of vertical convection, kept the weather fine, and formed a dry climate zone on the west bank of the subtropical continent [see Mediterranean (type) climate].In the western part of the high pressure, the downdraft and inversion are relatively weak, so that the warm and humid air that converges and rises at the lower level is easy to break through the inversion layer and form convection, so the thunderstorm shower weather is frequent.
The West Pacific High and the North Pacific High are generally divided into two large monomers in summer: the large monomer in the West Pacific is called the West Pacific High, and the large monomer in the East Pacific is called the East Pacific High.In the westerly belt on the north side of the ridge line of the Western Pacific High, cyclones and fronts are active frequently, often producing cloudy rain or rainstorm weather.
Encyclopedia x confusion: illustration of subtropical high pressure zone
The main rain belt in eastern China is often located 5~8 latitudes north of the high pressure ridge.Seasonal variation of the western Pacific ridge corresponds to seasonal displacement of the main rain belts in eastern China.On average, in May, the ridge line of the high pressure is located near 15 ° north latitude, and the main rain belt is located in South China. In June, the ridge line crosses 20 ° north latitude, and the main rain belt is located in the middle and lower reaches of the Yangtze River andHuaihe River Basin, bringing the Jianghuai area into the Meiyu period;In the middle of July, when the ridge line crosses 25 ° north latitude, the main rain belt moves toYellow River BasinThe rainy season begins in North China. At this time, the Jianghuai River Basin is under the control of the high pressure ridge line. After the Meiyu period ends, it enters the summer drought period. The weather is extremely hot with little rain.The south side of the ridge line is the easterly belt, which often has easterly waves and typhoon activities, producing a lot of precipitation.Therefore, after the middle of July, another rain belt appeared in South China.The mutual configuration of western Pacific high and typhoon determines the moving path of typhoon.When the high pressure is strong and the ridge line is east-west, the typhoon moves westward steadily;When the ridge of the high pressure is northwest southeast, the typhoon is easy to move northwest and land in China;If the high pressure weakens and breaks, typhoons tend to land northward or turn.
Distribution rule
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Subtropical high pressure zone (Figure 4)
Subtropical high pressure zone, located in the Northern HemisphereNorthwest PacificSubtropical high over.[6]It is distributed in the west bank of the continent between 30~40 ° south and north latitude.It is also widely distributed and is the only climate type in all continents except Antarctica.Subtropical highThe eastern part of the area is a strong subsidence movement area, and the subsidence flow is warmed due to adiabatic compression, and there will be continuous sunny and hot weather in the controlled area.The western part of the subtropical high is the area where the warm and humid air at the lower level converges and rises, which is prone to thunderstorms.
As the seasons change,Subtropical high beltThere will also be obvious seasonal changes in the intensity and location of.From January to July,Subtropical highThe main body shows a trend of northward and westward movement and strength enhancement;From July to January, the main body of the subtropical high moved southward and eastward and its intensity weakened.This seasonal change also has different stages of obvious slow change and leap change.
The subtropical high pressure zone is located in the warm high pressure in the subtropical region.It is about 30 degrees south and north latitude.This high pressure zone is the boundary between the prevailing westerlies and easterlies, and the westerlies are on the high latitude side.Under the control of the subtropical high, the weather is sunny, and the northwest side of the subtropical high is the southwest air flow jump control area (through the rain area).The high pressure between the tropical and temperate zones is called the subtropical high, and the one that controls the Pacific region is usually called the Pacific subtropical high.It varies with seasons and generally moves between 10 ° N and 40 ° N.
Climatic characteristics
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The relationship between pressure zone and precipitation is generally believed that under the control of high pressure zone, there is less chance of precipitation, while under the control of low pressure zone, there is more chance of precipitation.Subtropical high pressure zone and polar high pressure zone: downdraft prevails and precipitation opportunities are few.The reason is that the air flow is sinking and the temperature is getting higher and higher, which is not conducive to water vapor grasping.Equatorial low pressure zoneSub-polar Low : Upwelling prevails and there are many opportunities for precipitation.The reason is that the air flow rises and the air resistance gradually decreases, which is convenient for the condensation of water vapor.[3]
China is affected by the subtropical high pressure zone as follows.In different parts of the subtropical high, the weather conditions are different.In the vice high altitude region, the weather is generally sunny, so when it controls a region for a long time, it will often cause long-term high temperature and drought in the region, but when the conditions are appropriate, local thunderstorms will also occur;On the south side of the subtropical high is the area where typhoons are frequently active. In its easterly flow, easterly waves often form and move westward, affecting areas east of Guizhou and Guangxi and south of the Yangtze River, where thunderstorms and torrential rains occur;On the north and northwest sides of the subtropical high, due to the southerly flow in the west bringing a large amount of water vapor from the sea, when there are weather systems such as the westerly belt trough or vortex, large-scale rain belts will be generated.[4]
fromEquatorial low pressure zoneThe rising air flow, as the temperature decreases with height and the air becomes heavier, gathers at a distance of 4~8 kilometers from the ground, turns to the north-south direction and diffuses. At the same time, it is also affected by gravity, so the air flow moves forward and sinks at the same time. Each of them sinks near the ground at 30 ° north-south latitude, increasing the low air and pressure, forming two subtropical high pressure zones in the north and south. It is because of the accumulation of air,It is caused by power and belongs to warm high pressure.[2]
The subtropical high belt will affect the temperature of the area it controls.First, the equatorial low pressure is a thermal low pressure,Subtropical highHigh power pressure,Sub polar low pressureIt belongs to dynamic low pressure and polar high pressure belongs to thermal high pressure.
The equatorial low pressure generated by the "thermal low pressure" makes the air flow rise from the equator to the high altitude and flow towards the polar high pressure.The upper air flow does not consider the friction with the groundcoriolis force Under the influence of (the direction of the vertical air flow in the northern hemisphere is to the right, and the direction of the southern hemisphere is opposite), finally, the direction of the air flow is parallel to the latitude line near the latitude of 30 degrees, which blocks the movement of the air flow, causing the air to gather and sink, thus forming a dynamic high subtropical high.The subtropical high has a high temperature because of its low latitude and scarce rainfall due to air subsidence.
The atmosphere flowing continuously from the equatorial region accumulates and sinks, increasing the density and pressure of the atmosphere near the ground, thus forming a high-pressure belt.It belongs to warm high pressure formed by dynamic action.Due to the influence of land and sea distribution, the subtropical high belt is often cut off by the continental thermal depression in summer, and only remains in theoceanOn.[1]
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China
Generally speaking, from winter to summer, the subtropical high pressure in the western Pacific regularly moves from south to north;From summer to winter, retreat regularly from north to south.The warm high pressure zone in the transitional area between the tropical and temperate zones, affected by the distribution of land and sea, often breaks into several isolated warm high pressures, which are collectively referred to as the subtropical high.This high pressure is a lasting large-scale weather system that controls the tropical and subtropical regions. Its position and intensity vary with seasons.The subtropical high that affects China mainly includes the Western Pacific High, the Qinghai Tibet High and the South China Sea High. The Western Pacific High has the greatest impact on China, and is one of the main weather systems that cause changes in summer drought and flood in China.In different parts of the subtropical high, the weather conditions are different.
staySubtropical highIn the region, the weather is generally sunny, so when it controls a region for a long time, it will often cause long-term high temperature and drought in the region, but when the conditions are appropriate, sometimes there will be local hot thunderstorms;On the south side of the Western Pacific High is an area where typhoons are frequently active. In its easterly flow, easterly waves often form and move westward, affecting areas to the east of Guizhou and Guangxi, and south of the Yangtze River, where thunderstorms and torrential rains occur;On the north and northwest sides of the subtropical high, due to the southerly flow in the west bringing a large amount of water vapor from the sea, when there are weather systems such as the westerly belt trough or vortex, large-scale rain belts will be generated.According to statistics, this rain belt is generally east-west in the 5-8 latitudes north of the western ridge of the Western Pacific High.The rainy season in South China, the Meiyu period in the Yangtze Huaihe River and the rainy season in North China are closely related to the northward movement of the Western Pacific High.The length of time that this rain belt stays in a certain area is directly related to the drought and flood in the area.Generally speaking, the longer the rain belt stops, the more frequent floods occur, the shorter the stay time, and drought is prone to occur.The location of the Qinghai Tibet High is closely related to the Meiyu in the Yangtze River basin and the first day rainstorm in Shaanxi, Qinghai and Gansu.
1、 The southerly flow in the western part of the subtropical high is a natural "conveyor belt" that transports warm and humid water vapor from the Pacific Ocean to the eastern part of the mainland of China.As you know, high pressure refers to the distribution of air pressure;In terms of air flow, the subtropical high is a huge anticyclone. In the Northern Hemisphere, the air flows from the center of the high pressure clockwise outward, forming southerly air flow in the west of the high pressure;In terms of the temperature and humidity of large air masses in a wide range, the subtropical high region is a huge humid and hot tropical ocean air mass.In the summer half year, it is the southerly airstream in the west of the subtropical high that continuously transports the humid and hot air of the tropical ocean air mass formed in the subtropical Pacific Ocean to the vast areas of China's mainland, thus providing sufficient "raw materials" for the formation of precipitation;At the same time, it also imports part of the heat of the subtropical ocean into China along with the air flow, making the summer temperature of China generally higher than that of other regions in the world at the same latitude. This "contribution" is also indispensable.
2、 The strength and position of the subtropical high is the "baton" that directly affects the distribution of summer rain belts in China.It is not difficult to understand that the southerly flow in the western part of the subtropical high is actually the southerly wind, a branch of the humid and hot summer wind that prevails in summer: the southeast monsoon.However, the humid and hot air flow only provides the possibility for precipitation. Only when it collides with the cold air from the north to the south can a large-scale rainfall belt be formed.It is precisely because the position of the subtropical high changes with the seasons: winter is south and summer is north, which makes the frontal rain belt in China gradually advance from south to north in the summer half year, so the rainy season in the south and north starts at different times.At the end of spring, the rainy season begins in Nanling.At the beginning of summer, the subtropical high increased its power and expanded northward and westward. The warm and humid southerly air flow moved northward along the western edge of the subtropical high and collided with the dry and cold air from the north in the Jianghuai region, forming the Meiyu weather.In midsummer, the subtropical high, which has become more powerful, continues to jump north, and the rain belt is pushed to North China and Northeast China.In autumn, the subtropical high retreats south, and the rain belt moves south with it.This is the reason why the rainy season in southern China starts early and ends late and lasts long, while the rainy season in northern China starts late and ends early and lasts short.
3、 The "camp" in the center of the subtropical high must be a big "stove".From July to August, the Jianghuai area, which is located in the "camp" of the subtropical high, was affected by the high-pressure downdraft. The temperature rose, the water vapor was not easy to condense, and the weather was hot and dry, forming a hot and dry weather: people were sweating, agricultural production had a heavy task of drought resistance, industrial production and people's domestic water was tight, and many students were suffering from the heat.It is the "credit" of the subtropical high to build such a big "stove".
4、 The abnormal subtropical high is the main cause of drought and flood disasters in China.In summer, the weather in eastern China changes from sunny to rainy, cold to hot, largely depending on the strength of the subtropical high.Once the position and strength of the subtropical high are abnormal, the position and strength of the southerly flow of the southeast monsoon in its west will change accordingly.When the summer monsoon is strong, the front will soon advance to the north;In weak years, the front hovers in the south.Where the front lingers for a long time, it is often rainy. Where the front lingers for a short time, it is often short of rain.It can be seen that in the summer half year of our country, at the same time, it is often waterlogging here and drought there;In the same area, there are often floods at this time and droughts at that time, which is largely due to the subtropical high.Therefore, the interannual variation of precipitation throughout China is quite large, and large-scale drought and flood disasters often occur.
Summer situation
staySubtropical highThe different parts of the area often cause long-term high temperature and drought, but when the conditions are appropriate, sometimes there will be local hot thunderstorms;On the south side of the Western Pacific High is an area where typhoons are frequently active. In its easterly flow, easterly waves often form and move westward, affecting areas east of Yunnan and Guizhou and south of the Yangtze River, where thunderstorms and torrential rains occur;On the north and northwest sides of the subtropical high, due to the southerly flow in the west bringing a large amount of water vapor from the sea, when encountering weather systems such as the westerly belt trough or vortex, large-scale rain belts will be generated.
According to statistics, this rain belt is generally east-west in the 5-8 latitudes north of the western ridge of the Western Pacific High.The rainy season in South China, the Meiyu period in the Yangtze Huaihe River and the rainy season in North China are closely related to the northward movement of the Western Pacific High.The length of time that this rain belt stays in a certain area is directly related to the drought and flood in the area.Generally speaking, the longer the rain belt stops, the more frequent floods occur, the shorter the stay time, and drought is prone to occur.
Drought causes
In the area under the control of the Western Pacific High Pressure, there is a strong subsidence inversion, which makes it difficult for the low-level water vapor to form clouds and rain, resulting in a stable weather with clear skies for thousands of miles, and a large-scale drought may occur after a long time.
The subtropical high is an important system to transport water vapor to the mainland of China.Although the water vapor source of precipitation in China mainly depends on the southwest air flow from the Indian Ocean, the location, intensity and activity of the Pacific subtropical high are not only related to the water vapor transport of the southwest air flow, but also affect the water vapor transport from the southeast monsoon to the mainland from the Pacific Ocean to the south.At the same time, the northern side of the Western Pacific subtropical high is the zone where the warm and humid air moving northward along the subtropical high intersects with the cold air moving southward at mid latitude, which often forms a large range of rainy weather and is an important precipitation zone in China's mainland.
Therefore, the south-north movement of the precipitation belt in China is consistent with the seasonal activity of the western Pacific subtropical high, which is usually located at 5-8 latitudes north of the ridge line of the subtropical high.
From February to April every year, when the subtropical high ridge line is stable between 18 and 20N, continuous cold and rainy weather occurs in South China.In June, the ridge line of the subtropical high jumped over 20N to the north and stabilized between 20 and 25N. The precipitation belt is located in the lower reaches of the Yangtze River and Japan, which is the beginning of the plum rain season.Because the strength of the subtropical high is different every year, the speed of its northward advance is different, and the length of the Meiyu period is very different from the morning and evening when it enters and leaves the plum blossom.Plum rains can occur in various periods from May to July.The plum rain that occurs in May is called early plum rain. The plum rain that occurs from June to July is called normal plum rain.Generally, the plum blossom comes in around the middle of June, and comes out in the first ten days of July. The average plum rain period is about 20 days.
The synoptic systems that cause the continuous rainfall process in the Meiyu period are mainly the quasi-static front, shear line and southwest vortex.
The continuous occurrence, movement and stagnation of these systems in the middle and lower reaches of the Yangtze River can cause large-scale floods.In July, the ridge line of the subtropical high jumped northward again, and the rainfall belt moved from the Yangtze River basin to the Huang Huai River basin.Meiyu in the middle and lower reaches of the Yangtze River ended and began to be controlled by the Western Pacific subtropical high. The weather became hot and rainy.If the subtropical high is strong and controlled for a long time, it will cause serious drought.From the end of July to the beginning of August, the high pressure ridge further crossed 30 ° N, and the rain belt also moved northward to North China and Northeast China.In the first ten days of September, the ridge of the high pressure began to bounce back to the south, and the rain belt also moved from north to south.
The above situation is just the general rule of the influence of the subtropical high activity in the western Pacific on the weather in China.
In fact, the seasonal movement of the subtropical high in the south and north is often abnormal, resulting in drought in some areas;The abnormal weather of waterlogging in other areas.
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The subtropical high is a high pressure system in the subtropical regions of the Northern Hemisphere. Its horizontal range can reach thousands of kilometers.The subtropical high is a planetary scale weather system - a weather system with a horizontal scale of more than 3000 km and a life span of 3 to 10 days or more. In the weather system, the horizontal scale and time scale are both the largest.It exists all year round and is a stable and less dynamic warm deep weather system.In summer, because of its high intensity, it covers almost 1/5 to 1/4 of the entire northern hemisphere area;In winter, its strength and scope will decrease.[8]
Generally speaking, the subtropical high is mainly active between 130 ° to 180 ° E and 20 ° to 30 ° N in summer.But it is extremely restless and likes to turn around.In summer, the subtropical high is mainly located in Chinasouth China、Jiangnan、Yangtze and Huai rivers、Huanghuai RiverAnd other eastern monsoon regions.In its heyday, its power also expanded to the east of southwest China and the southeast of northwest China.rain beltChangeshigh temperatureThe duration oftyphoonMost weather changes are inseparable from the trend of.[8]
The subtropical high is a "rain making machine". Its strength and position are the "baton" that directly affects the distribution of summer rain belts in China.The southerly flow in the west of the subtropical high is a natural "conveyor belt" that transports warm and humid water vapor from the Pacific Ocean to the east of China's mainland, while the easterly belt in the south of the subtropical high is an active area of tropical precipitation system.Generally speaking, every year from winter to summer, the subtropical high will regularly move from south to north;From summer to winter, retreat regularly from north to south.The south-north movement of the precipitation belt in China is consistent with the seasonal activity of the subtropical high. Generally, the precipitation belt is located at 5 to 8 latitudes north of the ridge line of the subtropical high.As its position moves from south to north, from March and April of each year, our country has successively experienced the pre flood season in South China, the plum rain in Jiangnan - the middle and lower reaches of the Yangtze River - the Yangtze Huaihe River basinRainy season in North China, Northeast rainy season, etc.[8]
The subtropical high can keep the fever in many places.The area controlled by the subtropical high is equivalent to a large steamer on the ground, and there will be continuous sunny and hot weather.This is because the downdraft prevails in the interior of the subtropical high, the air temperature increases strongly, and the low-level water vapor is difficult to form clouds and rain;In addition, the pressure gradient is small, so the wind force is minimal.In this state, the solar radiation can reach the ground more, making the ground and near ground atmosphere get more heat, and the atmospheric temperature rises significantly.Therefore, in areas controlled by the subtropical high, there is often high temperature and little rain.If the subtropical high is strong, it is very easy to open the "barbecue" mode, and the local air temperature even breaks the historical extreme value.[8]
Subtropical high ortyphoon"Baton".Most typhoons affecting China are generated in the northwest Pacific Ocean.Typhoons generated in the northwest Pacific mostly originate in the southern edge of the subtropical high and move along the periphery of the subtropical high.Generally speaking, when the subtropical high is east-west banded and its strength is stable, the typhoon on its south side will move westward and its path is stable;If the intensity of the subtropical high is not strong, when the typhoon moves to its southwest, it will cause the subtropical high to retreat to the east and contract to the sea, and the typhoon may also move northward;In addition, typhoons can break the weaker subtropical high and move northward through its middle.[8]
