Why don t typhoons occur at the equator?

Typhoon is a kind of cyclone, and its formation requires a sufficiently large geostrophic deflection force, and the Earth's rotation is conducive to the formation of cyclonic vortices, while the geostrophic deflection force at the equator is basically zero.

There is no geostrophic deflection force in the equatorial region, and the convection can only move vertically up and down, or slightly horizontally, and this atmospheric movement mode cannot form a cyclone.

The formation of a typhoon requires the formation of a heat source, known as a system of low pressure, over the tropical ocean. At the equator, the heat is uniform, and the pressure gradient force is very small.

We know that the equator is a very important parallel for the Earth. This place is a privileged environment for the best growth of flora and fauna. It is understood that more than half of the species exist near the equator, the temperature here is very suitable, and will not be affected by typhoons, some friends will be curious, why there are no typhoons at the equator.

Because of the equatorialGeostrophic deflection forceis zero, and this is a necessary factor for the formation of a typhoon, so there will be no formation of a typhoon near the equator. In addition, typhoons formed by Ushiken in other places are difficult to harm the equator, because there are many warm and countercurrent currents, which can be said to be very safe.

In order to form a typhoon, four conditions need to be met, and all of them are indispensable, which are geostrophic deflection force; sufficient water and gas resources; 28 or more air flow; Powerful subtropical high pressure.

Centre. However, the equator does not meet the first condition in the first place.

The equator is a depression.

When it is about to reach the west coast of the ocean, it will be blocked by the land, so some of them will turn back and form a countercurrent. The other part of the warm current reaches the east coast of the ocean and forms a compensating current, so the equator is still far away from the center of the subtropical high.

The main location of the typhoon.

Generally speaking, typhoons mainly occur at latitudes of 5-20°, especially 10-20° is the most likely to occur, while the latitude of Chi Rolling Xiangdao is 0°, so it is not within this range. Typhoons mainly occur in 8 sea areas, including 5 in the northern hemisphere and 3 in the southern hemisphere, such as the eastern and western parts of the North Pacific.

Anyone with some general knowledge of geography will know that there are no typhoons in the equatorial region. However, it is estimated that few people can clearly explain the reasons for the absence of typhoons in the equatorial region.

Typhoon formation condition 1: Sufficient heat There are many factors for the formation of typhoons, and one of the most important factors is to have enough heat. Because only when a certain amount of heat is reached, the water will evaporate and a low-pressure area will be formed.

A huge reverse force is formed from the high-pressure area to the low-pressure area.

Condition 2: The sea surface temperature is high enough, which is also an important reason for the formation of typhoons. When a true bay is reached. Water vapor is formed when heat is generated, and the formation of water vapor tends to form a low-pressure center.

Where the water temperature is relatively low, a high-pressure center will be formed, from the high-pressure center to the low-pressure center. There will be a reverse force, and this opposite force will promote the formation of the typhoon.

Condition 3: The geostrophic deflection force has a sufficiently high water temperature and a sufficiently high heat rate, but there is still no way to meet the conditions for the formation of a typhoon. So the question is, how to completely form a typhoon, in fact, there is an external condition to be met, that is, to have geostrophic deflection force.

Geostrophic deflection forces occur only in regions above latitudes of more than 5°. The latitude of the equatorial region is 0°, so the equator does not meet the factors that produce geostrophic deflection forces. This also means that typhoons will definitely not form in this area, because it cannot meet the basic factors for the formation of typhoons.

To sum up, there are many natural conditions for the formation of typhoons. It is a comprehensive factor, and the absence of any of these conditions cannot form a typhoon, because there is no above-ground bias force in the equatorial region, so it is said that the conditions for the formation of a typhoon cannot be met. In other words, there are no typhoons at all in the equatorial region.

Because the conditions at the equator are not suitable for the formation of typhoons, the geodetic pressure in the formation of typhoons needs to be large enough, but the geodetic pressure in the equatorial region is basically zero.

There are no conditions for the formation of a typhoon at the equator, and three conditions are required for the formation of a typhoon: higher temperatures; a constant stream of abundant water vapor; At the agitation where the trade winds of the northern and southern hemispheres meet, the air rises strongly in the vertical direction, and the horizontal direction is subject to a large deflection force of the floor tiles. However, the geostrophic deflection force at the equator is very small, and it is not easy to form typhoons.

The geostrophic deflection force is very small (i.e., close to the equator), and the relative vorticity of the typhoon is also very small at the beginning, although there is a certain convergence flow field, the vorticity is difficult to generate or is not easy to generate quickly, and the typhoon circulation cannot be reached. Therefore, in and around the equator, typhoons cannot form. Typhoons can occur only at a certain latitude from the equator, usually five latitudes from the equator.

The effect of geostrophic parameters is conducive to the generation of cyclonic vortices. For a given convergence value, the change in vorticity over time is proportional to the magnitude of the absolute vorticity. At the equator f=0, if the relative vorticity of the disturbance is also zero, the vorticity of the disturbance does not increase, regardless of the size of the radiation.

In the region f≠0 at a certain latitude away from the equator, the convergence can cause an increase in the vorticity, and for the same convergence, the further away from the equator the vorticity generation rate increases.

As a result, typhoons all occur in the tropical oceans 5 latitudes away from the equator, with only a few typhoons in the northwest Pacific forming around 3°N. However, typhoons are rarely found within three latitudes near the equator.

a.The geostrophic deflection force of the equator is zero.

b.The equatorial range has a small land area.

c.The temperature at the equator is too high.

d.The temperature at the equator is too low.

The reason why the equatorial region is calm all year round is very simple, and it is due to the existence of the "equatorial windless belt". The equatorial region has the smallest temperature difference in the world, so the pressure is so evenly distributed that the air cannot move and there is no wind.

Within 400,500 kilometres of the equatorial line, it is meteorologically known as the "equatorial windless belt". Sail there, the ship does not jolt, the man does not vomit; Blue sky, calm sea, let the seabirds fly. In particular, the colorful tropical forests on the island are truly refreshing and beautiful.

The reason why the equatorial region is calm all year round is very simple, in a word, it is due to the existence of the "equatorial windless belt". So, why is there an equatorial windless zone?

We know that the movement of air is the wind. Whereas, the movement of air is caused by the presence of a high and low air pressure system in the atmosphere. Air flows from the high-pressure area to the low-pressure area, and the greater the difference in air pressure, the greater the wind, and the smaller the difference in air pressure, the smaller the wind.

This truth clearly tells us that the emergence of the equatorial windless belt is due to the fact that the air pressure distribution in the equatorial region is very uniform, and there is no high and low pressure system in the atmosphere, so that the air cannot flow, and the wind and waves are calm.

As for why the distribution of air pressure in the equatorial region is uniform, it is related to temperature. When the temperature in an area is high, the air pressure is low; If the temperature is low, the air pressure is high; If the temperature difference is large, the air pressure distribution is uneven; If the temperature difference is small, the air pressure is evenly distributed. The equatorial region has the smallest temperature difference in the world, so the pressure distribution is very uniform.

In addition, there is an invisible line of defense in the equatorial windless belt, which makes it impossible for "tropical storms" to form and difficult to enter. Because the rotation of the earth from west to east, in addition to the phenomenon of day and night, it also causes all moving objects on the earth, such as air, flowing water, rockets, ships, etc., to deviate to the right in the northern hemisphere and to the left in the southern hemisphere, which is the deflection force generated by the rotation of the earth. Under the influence of this force, tropical storms with high rotation speed can form in tropical areas around 15° latitude.

However, this force is zero at the equator and very small on both sides of the equator. As a result, tropical storms with high rotational velocity are not produced in the equatorial region. In addition, when a tropical storm forms in the tropics, it first moves west or northwest with the easterly wind over the tropics and then enters the westerly belt. However, no tropical storm has yet been seen moving eastward and northeastward into the equatorial region.

The equatorial windless zone provides a suitable environment for outdoor badminton. Badminton in Indonesia and Malaysia is very popular, and this is probably the reason for side shooting!