Typhoons generally move westward, why?

In the final analysis, the movement of the wind depends on the air pressure, and there is air pressure to move. For this reason, typhoons generally form in summer and autumn, when the subtropical high pressure is on the sea. At this time, China is under the control of the Asian low pressure, and the air pressure is relatively low.

The typhoon is on the edge of the subtropical high, so it must move from high pressure to low pressure. China is located at the western end of the Pacific Ocean, that is, the western end of the typhoon's origin, so the typhoon blows from the east of Western Europe to the west. But in essence, this is caused by the wind blowing from high pressure to low pressure, but our country is just to the west of the typhoon.

For example, the typhoon affecting China was formed under the whipping of the northeast trade winds on the south side of the strong subtropical high, and moved westward with the guiding airflow on the edge of the subtropical high. The eastward deflection is due to the fact that the typhoon reaches the west side of the subtropical high, and the guiding airflow changes to a southerly wind and eventually a westerly wind. (In the process of moving from low latitudes to high latitudes, the wind direction gradually changes from east wind to west wind).

Because the earth rotates from west to east, typhoons generally move westward relative to people on earth.

Because our geography in China is in the west of the Pacific Ocean.

Most typhoons form over the ocean

So typhoons generally move from east to west!

Because it generally occurs in the southeast.

The direction of typhoons can be roughly divided into three categories: westward moving type, landward type, and turning type. Typhoon path refers to the path that a typhoon travels after it has formed.

The main reasons for the various paths of typhoons are that typhoons are affected by factors such as complex atmospheric environment during atmospheric movement. Studying the path of a typhoon can help you prepare in advance, prevent and mitigate disasters, and reduce human and economic losses.

Typhoon tracks are one of the most important concerns in typhoon weather analysis and forecasting, as different paths will have different impacts on different places. In the Western Pacific, there are roughly three paths for typhoon movements.

The first is a westerly path, with the typhoon passing through the Philippines or the Balintang Strait and the Bashi Strait entering the South China Sea, and heading westward to Hainan Island or Vietnam, which will have a greater impact on China.

The second is the northwest path, where the typhoon moves west-northwestward, makes landfall in Taiwan Province, and then passes through the Taiwan Strait to make landfall in Fujian Province, which is also called the landfall path.

The third is the steering path, with the typhoon moving northwest from the sea east of the Philippines and turning northeast around 25°N towards Japan. This path has little impact on our country.

The above three paths are typical, with different paths prevailing in different seasons, generally in midsummer with landfall and steering paths, and in spring and autumn with westbound and turning paths.

The path of a typhoon is mainly affected by the atmospheric environment.

The dynamics that determine the movement of a typhoon can be divided into two types: internal and external. The internal forces of a typhoon are mainly caused by the geostrophic deflection forces associated with the rotation, air flow convergence and upward motion of the typhoon itself. The magnitude of the typhoon's internal force is directly proportional to the radius of the typhoon, the convergence and upward motion of the air in the vortex, and the magnitude of the tangential wind, and inversely proportional to the latitude where the typhoon center is located.

Under the action of simple internal forces, the trajectory of the typhoon center is a complex cycloid composed of superimposed sine waves and cosine waves with different amplitudes and the same period. The external forces of a typhoon mainly include the pressure gradient force of the environment (mean airflow), the geostrophic deflection force, and the friction force.

The dynamics of a typhoon.

The direction and speed at which the typhoon moves depends on the dynamics acting on the typhoon. There are two types of power: internal force and external force. The internal force is the resultant force to the north and west caused by the difference in geostrophic deflection force caused by the difference between north and south latitude in the typhoon range, and the larger the typhoon range, the stronger the wind speed, and the greater the internal force.

The external force is the force of the typhoon environmental flow field on the typhoon vortex, that is, the guiding force of the easterly belt of the basic airflow on the south side of the subtropical high in the northern hemisphere.

Typhoon is a strong cyclonic whirlpool with a warm central structure that occurs over the tropical ocean, always accompanied by violent storms and rains, which will cause serious disasters to the affected areas, and has the characteristics of strong destructiveness and wide range of impact. In the western Pacific, that is, China, Japan and neighboring countries call it a typhoon, in the eastern Pacific, countries such as Europe and the United States call it a hurricane, and countries in the Indian Ocean call it a tropical storm. The principle of typhoon formation is that the ground temperature is high, the air flow rises, the sea surface wind, saliva vapor due to the proportion of the rock ground to supplement the ground air, the sea surface temperature is low, absorb the air and water vapor rising from the ground to supplement the space, due to the large sea surface temperature difference is small, the sea surface over the accumulation of water vapor more, rainfall Fan Jing chaos is wide, the volume of water vapor shrinks when the water vapor is formed, and the surrounding water vapor is late to replenish the formation of a gale.

There are two types of forces that move a typhoon: one is an internal force and the other is an external force.

The internal forces are the forces generated by the typhoon itself. Because a typhoon itself is a mass of air rotating in an anticlockwise direction (Northern Hemisphere), the direction of movement of the air particles is deflected by the Earth's rotation as it rotates.

This bias tends to be greater for the typhoon to the higher latitude side than to the equatorial side; In the case of the typhoon as a whole, a force towards higher latitudes is generated, which is the internal force. It was this force that prompted the Taidong Fufeng to move northward.

The external force is the thrust of the air around the typhoon when it moves. In summer and autumn, there is often a separate high pressure (commonly known as the subtropical high) in the Pacific Ocean, and the wind direction around this high pressure is very important for the path of the typhoon. The typhoon occurred on the southern edge of the Pacific high, where strong easterly winds blew and the typhoon moved westward.

Path: Wanna is inseparable from its roots

You can't step into the same river twice", and it seems that typhoons never choose the same path. Typhoons often give the impression of being "capricious" when it comes to choosing their path. However, if you put together the paths of typhoons over the years, you will find that although the distances vary widely, most typhoons follow a set path of westward turn-north.

The reason for this is that the movement of the typhoon is mainly driven by the Pacific subtropical high. At first, the typhoon formed in a southerly position, and under the influence of easterly winds from the south, it moved westward. At higher latitudes, due to the increase of geostrophic deflection force, it began to drift northward, and gradually turned to the east under the influence of the westerly wind belt.

In specific cases, it is also very common to divide the typical path of a typhoon into three types: westward, landfall, and turn. In fact, there is no contradiction between these two statements.

The so-called westward type means that the typhoon has been moving westward since its formation until it makes landfall along the eastern and western coasts, Hainan Island, or Vietnam. These typhoons have only completed the first part of their set path: westward, weakening and dissipating due to landfall.

In the same way, a landfall typhoon dissipates due to landfall after completing two steps of westward advance and turning.