Double typhoon effect

Typhoons are probably one of the most common weather disasters in coastal areas, especially in cities like Fujian, Hainan, Guangxi, Zhejiang, and other parts of the country, which have endured typhoons almost as a matter of routine over the years.

Typhoon transit is bound to be accompanied by violent storms, sometimes that hurricane can lift the tin roof, and break windows, this time, not to mention going out, hurrying to fix the doors and windows at home, back to the safe position is the best policy.

But have you seen the "double typhoon effect"? A typhoon brought disaster to coastal cities has been full of destruction, if two typhoons collide together, what will happen? Or damage offset, or double the scope? It all depends on the actual situation!

How typhoons are formed

I'm sure many people have heard about the power of typhoons, so do you know how they are formed?

Simply put, for a typhoon to appear in front of everyone's eyes, it must first meet three conditions: water vapor conditions, thermal conditions, and power conditions. First of all, typhoons originate from the sea, why choose the sea rather than land? Because the sea can produce a constant stream of water vapor.

But the water vapor is not enough, we must wait until the summer, the strong light directly to the sea on the hot heat will make the water vapor rise, so that rainfall can be produced.

But before the arrival of rainfall, the evaporation of hot air will be put on the sea to form a low-pressure center, when the outside clouds and air backed up into the formation of the wind. A typhoon is also a form of wind, how to let the wind evolve into a typhoon, requires the use of the third condition we mentioned above: power.

By the influence of the earth's deflection force, the northern hemisphere is easy to form counterclockwise and to the center of the spokes of the maelstrom, while the southern hemisphere is the formation of clockwise maelstrom; when the vapor up in the vortex to form rainfall, and leads to clouds and wind backflow, the power provided by the vortex is sufficient to form a certain scale of the typhoon.

Water vapor and wind are often found on the sea surface, but maelstroms are very rare, and typhoons lacking that power are not easily formed.

But once a typhoon is generated by the interaction of the three conditions and gradually approaches coastal cities, it is very likely to cause a series of disasters.

Common typhoon disasters include "gale force winds", "very heavy rainfall" and "storm surge", with gale force winds of 12 or more having a serious impact on people's lives, destroying houses, breaking high-altitude facilities are broken, and those communication lines.

For coastal cities, heavy rainfall can easily lead to flooding, and in some places near mountainous areas, mudslides and landslides can be induced.

The disaster of storm surge is mainly concentrated in the sea, if there is a ship underway when encountering storm surge, fear is very easy to be overturned; storm surge will also affect the seawall stability, if the scale of the storm surge is too large, it will lead to submarine breaches, seawater back up, these disasters can not be considered not serious.

Then some friends are curious since a typhoon has such destructive power, then if two typhoons meet? They will not form a larger cyclone, which in turn brings serious threats to coastal and surrounding cities.

You do not say, this happened! There is a professional term for this phenomenon called the "double-stand effect", or "Fujiwara effect".

The Double Stage Effect

The double-stand effect was first conceptualized by Japanese meteorologist Dr. Fujiwara in 1923 when Dr. Fujiwara derived the typhoon evolution through vortex experiments: when two cyclonic vortices are close to each other, their rotational paths will be influenced by each other, and then show a tendency to approach or even merge.

However, Dr. Fujiwara's concept is rather idealistic, because, in reality, it is impossible to allow typhoons of equal size to come close to each other.

But Dr. Fujiwara's conjecture also inspired future generations, and modern meteorologists, through meticulous judgment, have classified the effects of twin typhoons into three categories: one-way influence, mutual influence, and merger.

Dr. Fujiwara was talking about mutual influence, but in reality, when twin typhoons meet, most of them are one-way influence and merger; that is, the stronger typhoon will completely take over the trajectory of the weaker typhoon, making the weaker typhoon continue to do counterclockwise movement around the stronger typhoon.

For example, Typhoon Timu, which erupted in the Philippine Islands in 1994, kept the surrounding tropical storm, Vanessa, firmly in its grip. Although Yunisha is in the sea and raises a lot of wind and waves, in the go, Tim is currently without the slightest resistance, but only arothe Tim near the continuous circle, which is undoubtedly a greater disaster for the surrounding.

But as said above, not all typhoons can do this integration, sometimes two typhoons meet either expulsion or engulfment, and human civilization is rather a lot of similarities. For example, the outbreak of super typhoon "Morakot" in 2009, Morakot made landfall near Kaohsiung County on the island of Taiwan, causing 461 residents to be killed and several thousand injured.

What we don't know is that as early as before Morakot landed in Kaohsiung, there was another typhoon "Swan" that was present in the surrounding waters. Typhoon Swan was first on the coast of Guangdong, then entered the Gulf of Tonkin and suddenly circled the western part of Hainan, and finally disappeared.

In fact, by the normal trajectory of the "Swan", it should land in Guangdong to the East China Sea after circling, but it suddenly changed its direction of travel westward, in addition to the influence of atmospheric circulation, for the "Morakot" landing to vacate the location is also the main reason. Who let "Morakot" is too dominant, "swan," said they really can not afford to mess with ah!

Double Taiwan effect in the real world is still relatively rare, especially the two evenly matched typhoons meet, which will indeed bring greater disaster to the surrounding coastal cities.

But the number of such cases is very small, especially in modern society, we have long accumulated a lot of experience on how to prevent the arrival of typhoons, and typhoons also continue to reduce the casualties. But in any case, when a typhoon comes, careful prevention is not a bad thing, evacuate the coast as soon as possible if necessary.